Type W

   The Brandenburg W was a three-bay, two-seat floatplane with the pilot occupying the rear cockpit. The Type W, Heinkel's first seaplane design for Brandenburg, had been designed pre-war as a racing machine.(23) Previously the races had taken place on inland lakes. In 1912, an attempt had been made to have the race on the open sea; however, even the calm Baltic was too much for the aeroplane structures of the day, and, despite the wish of the Navy to hold the contest off the coast of the Baltic or the North Sea, the 1913 race was held on Lake Constance as the aeroplane manufacturers stated that they could not design types to meet the conditions to be expected on the high seas. In 1914 the race was going to again be attempted on the open sea as the Ostseeflug Warnemunde (Flight over the Baltic Sea at Warnemunde). Heinkel was sure he could develop a seaworthy floatplane using the Albatros B.II as the basis for the design. According to his autobiography Heinkel designed the machine in eight weeks. The Type W was at Warnemunde together with 26 other seaplanes for the competition as the Navy had promised a small contract for the successful seaplanes. AEG, Ago, Albatros, Aviatik, Brandenburg, Friedrichshafen, and Rumpler had entered aircraft in the competition. The commencement of the war meant the competition was abandoned. All 26 aeroplanes were impressed into German Navy service.
   Of conventional construction this three-bay biplane was marked by its crude floats. These were 4.850 m long and 0.900 m wide with a single step. The wings had dihedral and a slight sweep-back. The 150-hp Benz Bz.II(24) engine was exposed with Hazet
side radiators mounted under the forward cockpit. The rectangular fuselage tapered to a vertical knife edge. An Avro type comma shaped rudder and tail float completed the fuselage.
   After testing the prototype, the German Navy ordered a total of 23 machines as listed above. The type performed general duties and reconnaissance work.

(23) Although Heinkel's autobiography indicates it was a race, it appears that the contest was more towards a set of conditions for performance on the water and in the air.
(24) Gray &Thetford record the 150-hp Bz.III as the type's engine.


Brandenburg W Specifications
Source Typenschau Gray & Thetford Branden. 3-View
Dimensions in m
Span, m 10.70 10.700 10.700
Length, m 10.24 10.240 10.130
Wing Area 57.65 m2 57.85 m2
Empty Wt., kg 1,200 1,200 1,200
Loaded Wt., kg 1,830 1,830 1,830
Performance
Speed in km/hr 90 90
Motor 150-hp Maybach 150-hp Benz Bz.III 150-hp Benz


The Brandenburg W Production
Marine Numbers Engine Delivered Notes
57 - 58 150-hp Benz Dec 1914 57 was ex-Ostseeflug Nr.26. 58 was ex-Ostseeflug Nr.25 and was converted into a landplane 21 October 1914.
71 - 72 150-hp Benz Listed as Brandenburg in Atlas &. Typenschau but identified as Ago designs by P.M. Grosz.
116 140 hp Argus Listed as Brandenburg in Typenschau but Lohner according to P.M. Grosz
231 - 235 Bz.III Jun-Jul 1915 Class BFT.
260 - 263 Bz.III Jan 1915 - Feb 1916 Class B.
264 - 273 Mb.III Class B. 269 was captured by the Russians near Schlock.
422 - 423 Bz.III Aug-Sep 1915
484 Bz.III Listed as Brandenburg by Typenschau but Lohner Type T by P.M. Grosz.

Type FB

   The FB was Brandenburg and Heinkel's first flying boat and was used with success by the Austro-Hungarian Navy in the Adriatic. The German Navy was not an enthusiastic supporter of the flying boat and preferred floatplanes; however, they ordered six of the Class C flying boats (MN 511-516). The FB was a large machine with a crew of two or three, two in the main cockpit back in line with the wings while the observer in the bow cockpit had a Parabellum machine gun for defence. The upper wing had a large overhang that was supported by an additional pair of struts that came from the base of the interplane struts. The square tipped planes were swept back and staggered. The single 165-hp Austro-Daimler engine was mounted in pusher configuration supported by a system of V-struts. The rudder was rhomboidal in shape and mounted half below and half above the tailplane. The tailplane was suspended above the hull by a two forward struts and the rudder post. A triangular fin was mounted on top of the tailplane. The elevator was in two pieces. Small floats were suspended under the lower wing.
   Designed for maritime patrol work, they were known as Lohner flying boats in the German Navy.
   FB boat MN 513 was based at Angernsee Seeflugstation where it was used with a number of Friedrichshafen FF33 floatplanes in attacks against the Russians. MN 513, together with Friedrichshafen MN 659, was involved in the shooting down of a Russian M.9 flying boat on 4 July 1916. It appears that it was the only Brandenburg flying boat operated by the station that also operated the Brandenburg GW torpedo aircraft.
   Ltn.d.RMA Friedrich Christiansen flew an FB, MN 516, at Zeebrugge that he named Klar Kimming and this was painted on the bow. The FB could operate in the winter when snow and ice prevented other air activity, the FB boats patrolling the areas where the German minesweepers conducted an endless campaign in trying to keep channels open to allow U-boats access to the North Sea. In a May 1917 return of aircraft all six of the FB boats were still in German Naval service.
   The kuk Kriegsmarine ordered an FB from Brandenburg that was delivered to Pola and received the number K184. It was almost identical with the German prototype MN 511.(2) The type was ordered from UFAG after a number of modifications were carried out to suit the Navy's requirements. The outer parallel interplane struts supporting the wing overhang were replaced by a vee-strut. The fin and rudder were replaced by a completely new design that was connected to the top of the hull. The engine was now a 175-hp Rapp with a different radiator built in Austro-Hungary. The UFAG version could carry a bomb load up to 200 kg.
   The type was ordered from UFAG in seven batches commencing with K168 - K175 ordered before the delivery of the German-built K184. The type had a good performance and proved popular. A second batch, K176 - K173, was ordered on 28 July 1917. K233 saw further modifications introduced with a new tailplane and more powerful engines. The last batch, K251 - K262, was never delivered.
   K222 was captured off Brindisi on 11 August 1917. The machine was described as a "Capa Flying Boat"(3) and was equipped with a 160-hp Austro-Daimler engine No. 7139. The pilot stated that the "engine gives about 200 hp." Two magnetos were fitted but were thrown overboard when capture was certain. The propeller was of ash and mahogany with alternate laminations (diameter 275, pitch 210).
   Two main fuel tanks were located in the hull under the centre section and occupied the full breadth of the boat. A gravity/emergency tank was let into the upper wing centre section. The pilot stated that the machine had an endurance of six hours and a speed of 150 km/hr.
   The front cockpit had a typical German circular gun mounting. "To assist the observer to climb from beside the pilot to the gunner's seat, a strong handle is fitted in the middle of the boat and half of the windscreen in front of the observer is detachable."
   Bombs were carried on the sides of the hull under the planes. "The pilot stated he carried one 150-kg bomb on the port side, and one 50-kg bomb and one 25-kg bomb on the starboard side." The machine gun and ammunition and Very pistol had been thrown overboard.
   The main planes had been torn from the boat and were very badly crumpled up. The wingtip floats were of unusual shape "the nose being covered with paper-mache." The interplane struts were large steel tubes streamlined by a light wooden framework covered with fabric. The struts holding the engine bearers were streamlined by three-ply wood fairings. "The fabric used is reported to be of excellent quality. The lack of copper was very noticeable."(4)
   A total of 66 Brandenburg (UFAG) FB flying boats entered service with the kuk Kriegsmarine. Although this may seem a small number when compared with the attrition of machines involved in the land war, this was a substantial number for a fighting flying boat.
   The UFAG-built K248 was one of two K-boats taken to the US after the war. K248 received Bureau No. A-5807. Its condition merited a Trouble Report of 16 September 1920, but the problems with the boat are not recorded. It was shipped to the Naval Aircraft Factory (NAF) on 20 December 1920, arriving in the following January. On 11 September 1920, the NAF reported that there was a hole about one foot square staved in the forward part of the bottom of the hull. The forward bulkhead was stove in. Ribs were broken in both upper and lower left wings. The cause of the trouble was not clearly evident. It was requested that it be repaired at the NAF. On completion of repairs it was to be sent to Hampton Roads for trials. It was flown to Anacostia in March 1921 before being shipped to Hampton Roads later that month. After trials, if any, it was placed into storage at Hampton Roads where it was subject to a Trouble Report of 6 February 1924. While it was reported to be in a fair condition, it was disassembled with the engine and instruments removed. Experiments and study were now completed with the machine in storage awaiting disposition. It was considered to be of no further use and it was recommended that the hull and wings be burnt but the engine and instruments be salvaged. A-5087 was stricken on 15 March 1924. No thought was given to preserving one of these flying boats.

(2) G. Haddow speculates that K184 may well have been MN 511 given the German Navy's little liking for flying boats.
(3) Allied intelligence was usually very well informed; however, it appears that in this case the nick-name for the Brandenburg was accepted as the official name for the flying boat. In Jane's All the Worlds Aircraft for 1920 K222 is described as a "Kappa"flying boat.
(4) UKNA AIR1/716/27/19/32.


Kuk Kriegsmarine Type FB (UFAG Type K) Orders & Production
Serials Delivered Notes
K184 9 July 1916 From Brandenburg, same as German prototype except for wingtip floats.
K168 - K175 Autumn 1916 175-hp Rapp.
K176 - K183 October-December 1916 175-hp Rapp. K177 - K179 160-hp Mercedes
W.20 Experimental submarine borne flying boat.
K200 Serial assigned to Weichmann flying boat. Incorrectly marked?
K203 - K212 December 1916 - January 1917 185-hp Austro-Daimler.
K213 - K224 January-February 1917 160-hp Austro-Daimler.
K225 - K232 May-June 1917 165-hp Austro-Daimler.
K233 - K247 August 1918 200-hp Hiero. Redesigned tailplane.
K248 - K250 230-hp Hiero. K248 to USA post-war.
K251 - K262 Order for 12 in September 1918, never delivered.
  

Brandenburg FB Specifications
Source Typenschau Brandenburg* Gray & Thetford Brandenburg SVK MN 511-516 Brandenburg G. Haddow Data UFAG
Span, m 16.00/10.00 16.0 16.000/10.000 16
Chord, Upper, m 1.90 - 1.900 -
Chord, Lower, m 1.83 - - -
Length, m 10.18 10.105 10.200 10.185
Height, m - - 3.600 -
Areas in m2
Wings 16.00/10.00 16.0 16.000/10.000 16
Ailerons 1.90 - 1.900 -
Elevators 1.83 - - -
Rudder 10.18 10.105 10.200 10.185
Weights in kg
Empty 1,140 1,140 1,033 1,100
Loaded 1,620 1,620 1,693 1,680
Performance
Speed in km/hr 140 140 - 155
Time to 800 m 8.5/9.5 minutes - 9.5 minutes -
Time to 1000 m 12.5 minutes 8.5 minutes 12.5 minutes 7.3 minutes
Time to 1500 m 16 minutes - 16 minutes -
Time to 2000 m 22 minutes - 22 minutes -
Endurance - - - 6 hours
Motor 100-hp Mercedes 100-hp Mercedes 100-hp Mercedes See Production
* The Typenschau does not list the UFAG-modified Type FB.

Type LW

   The LW equi-span reconnaissance floatplane was constructed for the German Navy in 1915. Only three LW biplanes were built receiving Marine Numbers 477 (CBMG Class), 485 (B Class) and 571 (C Class), and were delivered in August 1916. The LW featured inward sloping interplane struts on its two-bay wings, a feature to be reproduced on many Heinkel designs, and bore a resemblance to the C.I reconnaissance biplane Heinkel designed for Austro-Hungary. This arrangement together with the float bracing struts enabled the first bay to be devoid of bracing cables. Heinkel states that the LW was a more simple machine than the NW in order to allow it to carry a machine gun. The floatplane was equipped with a single Parabellum machine gun with 500 rounds for the observer who sat behind the pilot.
   Although only three were commissioned in the Navy, Heinkel's statement that it served as a "reasonably satisfactory armed seaplane at the front" has elements of truth. LW MN 477 and two floatplanes, NW MNs 487 and 521, of SFA 1 attacked Britain on the night of 19/20 May 1916.(30) The British recorded 59 of the 90 10-kg bombs that the Germans claimed as having been dropped during the raid. NW 521 was attacked near Calais on the return flight but arrived back safely. One person was killed and two injured during the raid.
   LW MN 571, also from Zeebrugge, claimed a Short seaplane in flames and a second one forced to alight as well as driving off a Short Baby (possibly a Sopwith Baby escort) on 1 October 1916, but crashed on the 17th while on a test flight, injuring the crew.(31)

(30) According to Cole and Chessman the raid was carried out by three Friedrichshafen FF33, three Brandenburg NW, and the Gotha Ursinus UWD floatplanes.
(31) This section written mainly from "The Hornets of Zeebrugge," Cross & Cockade, Vol. 11, No.1,1970, PP. 9-12.

Brandenburg LW Specifications
Source Typenschau Gray & Thetford Branden. 3-View*
Dimensions in m
Span, Upper 12.40 12.4 12.400
Span, Lower 12.40 - 12.400
Length, m 9.50 9.5 9.500
Chord, m - - 1.800
Wing Area 42.60 m2 42.6 m2 -
Empty Wt., kg 994 994 994
Loaded Wt., kg 1,555 1,555 1,555
Performance
Speed in km/hr 131 130 -
Time to 1000 m - 12 min 12 min
Motor 160-hp Mercedes 160-hp Mercedes D.III -
* Marine Number 571

Type NW
  
   The first Brandenburg designed as a warplane was the NW, a two-seat reconnaissance floatplane that could be fitted with radio in the Navy BFT Class of aircraft. The type was a marked improvement over the W and showed the continuing influence of Heinkel's pre-war three-bay Albatros floatplanes. The NW was a large floatplane with slight sweep back to the wings. The floats were an improvement over those fitted to the Type W and had a single step. The radiator for the engine was carried on the centre section struts being mounted in front of the upper wing. The observer occupied the front cockpit under the wings. A total of 60 were supplied to the German Navy during 1915, including a batch of 30 built by Gotha under licence. Some were fitted to carry up to ten 5-kg bombs for use against enemy vessels.(25) Initially the Benz Bz.III engine was proposed for the batch MN 601 - 608 but the 160-hp Mercedes D.III was installed in all batches.
   The first four were assigned in early 1916 to bases at Borkum, Norderney and Heligoland. This dispersal says much for the state of the German Navy's aeronautical efforts prior to and during the early days of the war.
   The NW was used for daylight raids on the English coast, participating alone or in company with other aircraft. Attacks took place on 9 and 20 February, 19 March, 3 May 1916. The War Diary of Zeebrugge recorded that NW. MN 521, along with the Gotha UWD MN 120, Friedrichshafen FF33B MN 457; FF33E MNs 473 and 547, and FF33F MN 537, of See Flieger Abteilung 1 carried out an attack on Sunday, 19 March 1916. The machines bombed Dover, Deal, and Ramsgate. Fourteen people were killed and considerable damage caused. The CO of Zeebrugge, Oberleutenant-zur-See von Tschirschsky und Bogendorff, led the raid in Christiansen's usual Brandenburg. This machine and another were forced down at sea and narrowly escaped destruction.
   Dover received no warning of a raid and the RNAS station knew of it when a bomb exploded in the town. None of the four aircraft from the RFC, Dover, saw the enemy. The RNAS launched 24 aircraft, three of which suffered forced landings. Friedrichshafen MN 537 was engaged by a Nieuport 10 from Detling piloted by Flt. Cdr. R.J. Bone. Bone, the CO of Detling, had predicted the likelihood of a raid and, having fully loaded his ammunition, flew to Westgate where he waited with a thermos of coffee and sandwiches. He followed the seaplane towards the Belgium coast and after a 40-minute chase attacked. He was met by the observer's fire but sent the Friedrichshafen down with the propeller stopped and the engine smoking. Not having enough petrol to follow, he returned and a Short seaplane was sent out to bomb the enemy machine that was last seen on the water, but discovered nothing. The machine had been towed back to base.(26)
   The Brandenburg NW was attacked by an RFC F.E.2b piloted by 2nd Lt. Reginald Collins with Flt. Sgt. Alfred Emery as observer. Collins was flying the new machine to France and when he noticed the defender's fire on the attacking seaplanes, he placed himself in a position to cut off their retreat. Attacking from above and behind he gained to within 150 yards behind the Brandenburg that had not seen him and Emery opened fire. The NW went into a steep right-hand spiral with steam streaming from its engine. The F.E.2b then lost sight of their victim. Collins attack had wounded the pilot and damaged the radiator. Von Tschirschky climbed out onto the wing and fixed the leaking radiator with his handkerchief and insulation tape, enabling the machine to stay in the air and they eventually came down about 20 miles from Ostende. Further repairs were effective as they managed to take off again and reached Zeebrugge.(27)
   On 24 April 1916, NW seaplanes MNs 487 and 521 are recorded as being amongst six seaplanes that bombed ships in the Channel. On the night of 19/20 May 1916, LW MN 477 together with two NW floatplanes, MN 487 and 521 attacked Britain. This attack killed one and injured two but otherwise did little damage. Flt. Sub-Lt. R.S. Dallas claimed one aircraft shot down but See I lost no aircraft on this raid.
   The Austro-Hungarians ordered a Brandenburg NW on 3 March 1916, to evaluate the type in order to replace their Lohner L flying boats. The NW was given the kuk Kriegsmarine Serial K148. The Benz Bz.III engine was replaced by a 165-hp Rapp engine sometime before it was wrecked in a forced alighting at Fasana on 18 June 1916. A Friedrichshafen FF33H had been obtained at the same time, receiving the serial K149, and it suffered a forced alighting due to engine failure and it too was wrecked. No orders were forthcoming from the kuk Kriegsmarine for either of these two floatplanes.
   The German Naval contingent in Turkey was supplied with a number of NW floatplanes in January 1917 as follows: MNs 603, 604, 608, 760, 770, 771, 774 and 781. MN 603 was transferred to the Ottoman Navy in January 1918.(28) This NW floatplane was named Eregli 1 (Eregli 2 was a Gotha WD.13). Eregli 1 was operated by 2NCI Deniz Tayyare Bolukd from Eregli where it operated against the Russians in the Black Sea. After suffering storm damaged on 1 August 1917, it was flown to Yesilkoy for repairs. On its return flight it had a forced alighting and was wrecked. The remains were later towed to Eregli.
   On 4 April 1917 a Brandenburg (type not identified) dropped two bombs on a Russian submarine. A hit was observed on the superstructure and the submersible was seen trailing a large amount of oil.
   On 11 June, Brandenburg NW 760 was on a reconnaissance flight when it had to alight. In response to its call for help Brandenburg GNW MN 654 flew to pick up the crew but it crashed on alighting. Brandenburg MN 774 was then sent out and found the two stricken aircraft and thankfully their crews were still alive. It alighted safely and all were saved. MN 770 was lost in October but the crew managed to swim to shore.(29)
   Post-war Poland received at least one NW by the end of 1921. This received the Naval serial No.6.

(25) Dr. Fritz Stormer recalled that these 5-kg bombs "did not produce great results, but they did damage the ballast tanks on submarines and thereby made them unable to submerge. In other uses, the bombs were good for our morale, as the shock caused by the explosion was quite impressive." Stomer flew Brandenburg seaplanes from Zeebrugge. Stomer, F. "Seaplanes in Combat", Cross & Cockade Journal, USA, Vol.20, No.2, 1979, P.111.
(26) Bones'report is contained in UKNA AIR1/646/17/122/352.
(27) The account given in Cole, C. & Chesman, E. F., The Air Defence of Britain 1914-1918, Putnam, UK, 1984, states that the observer was wounded. Gutman, J. Naval Aces of World War 1, Part 2, Osprey, UK, 2012, states that both von Tschirschky and Christiansen were wounded.
(28) Nikolajsen, O. Turkish Military Aircraft Since 1912, self-published, France 2007.
(29) This section is mainly based on Nikolajsen, O. Turkish Military Aircraft Since 1912, self published, France 2007.


Brandenburg NW Production
Marine Numbers Class Delivered Notes
486 - 489 B July-Dec 1915 485 - 489 are listed as NW in Typenschau
517 - 526 BFT Oct.1915 - Nov.1916
563 - 570 BFT Nov.1915 - Dec.1916
601 - 608 BFT Delivered late 1916, early 1917
752 - 781 Gotha-built under licence


Brandenburg NW Specifications
Source Typenschau Gray & Thetford SVK MN 602 (601 - 608) SVK MN 756 (752 - 781)
Span, m 16.27/15.27 16.5 16.270/15.270 16.270/15.270
Length, m 9.85 9.4 9.850 9.850
Height, m - - 3.750 3.750
Chord, m - - 1.800 1.800
Wing Area, m2 55.00 57.85 - -
Empty Wt, kg 1,020 1,020 1,052 1,032
Loaded Wt, kg 1,648 1,650 1,575 1,614
Performance
Speed in km/hr 122 90 - -
Time to 500 m - - 5.5 minutes -
Time to 800 m 7 minutes - 9 minutes 7 minutes
Time to 1000 m 9.5 minutes - 11.5 minutes 9.5 minutes
Time to 1500 m - - 20 minutes 15.5 minutes
Time to 2000 m - - - 22.5 minutes
Motor 160-hp Mercedes 160-hp Mercedes D.III 160-hp Mercedes 160-hp Mercedes


German Naval Seaplane Group in Turkey
Marine Numbers Entered Service Written Off Notes
603 04.17 Transferred to Ottoman Navy
604 04.17
608 04.17
760 04.17 11.06.17 Forced alighting Black Sea
771 04.17 16.05.17 Forced alighting Aegean Sea
770 06.17 28.10.17 Ditched Black Sea
774 06.17
781 08.18 Ex-2DzTyBl


Type GNW
  
   The GNW was an unarmed three-bay two-seat biplane development of the NW reconnaissance seaplane. While there was no improvement in speed over the NW, it had a better climb. According to the Typenschau the type was designed to carry 10-kg bombs and had an endurance of 514 hours.

Brandenburg GNW Specifications
Source Typenschau Gray & Thetford Brandenburg 3-View SVK MN 629 (625 - 632 & 651 - 658)
Span, m 16.20/15.20 16.2 16.200/15.200 16.200/15.200
Length, m 9.65 9.88 9.650
Height, m — — — 2.750
Chord, m — — 1.800 1.800
Wing Area, m2 55.15 55.15
Aileron Area, m2 7.30 — — 7.30
Elevator Area, m2 1.65 — — 1.65
Rudder Area, m2 1.00 — — 1.00
Empty Wt, kg 1,100 1,100 1,078
Loaded Wt, kg 1,743 1,743 — 1,647
Performance
Speed in km/hr 115 115 — —
Time to 800 m — — — 8 minutes
Time to 1000 m 9.5 minutes 9.5 minutes — 10.5 minutes
Time to 1500 m — — — 17 minutes
Time to 2000 m — — — 26 minutes
Motor 160-hp Mercedes 160-hp Mercedes D.III 160-hp Mercedes 160-hp Benz


Brandenburg GNW Production
Marine Numbers Class Delivered Notes
625 - 632 B Sept. - Oct. 1916 The British illustrated MN 625 in their publication Types of German Seaplanes, and identified the type as the "Brandenburg-Gotha Seaplane 1916."(32)
651 - 658 BFT Sep. 1916 - Jan. 1917 628, 653 and 654 were delivered to the German Naval contingent in Turkey.(33)
(32) This booklet was printed by the Air Ministry, Air Intelligence (A.I.4), and dated July 1918. It was "not to be carried in aircraft." Each type was identified by photographs and silhouettes with a general description but no specifications. It details a total of 25 marine aircraft: 1 Albatros; 9 Brandenburg; 9 Friedrichshafen; 3 Sablatnig; 1 Rumpler and 2 Gotha seaplanes. The Brandenburgs illustrated are the KDW (2 entries, one probably the W.11); the NW; W.12; GW; GDW; GNW floatplanes and CC and FB flying boats.
(33) Nikolajsen, O. Op Cit.

Type CC

   The German Navy displayed interest in a single seat flying boat that Brandenburg had designed for the "star-strut" interplane strut system and placed an order for a single example in May 1916, MN 946. The machine was given the designation Type CC,(11) after Camillo Castiglione the proprietor of the Brandenburg works. The 150-hp Benz Bz.III engine was mounted in pusher configuration high up under the top wing by steel tube struts that replaced the flying and landing wires. These struts were given wooden aerodynamic fairings. The radiator was mounted directly in front of the engine. The wings resembled those of the KD landplane, square cut with ailerons incorporating washout only on the upper wing. The wooden hull featured a single step and tapered to a vertical knife edge where was mounted the balanced rudder. The rectangular tailplane was mounted high above the fuselage by two metal struts on each side. A curved ply covered fin completed the tailplane. Small floats were suspended under the lower wing near the strut attachment points. Armament of the prototype was a single machine gun that protruded through the windscreen. Production machines had two machine guns mounted each side of the windscreen.
   Testing must have proved adequate as two batches for a total of 35 aircraft were ordered. Boats in the second production run had a longer and wider hull than the prototype. Later aircraft had an additional pair of struts to brace the upper wing overhand, thus negating any benefit of the star strut arrangement. It is assumed that his modification was retro-fitted to the surviving earlier CC boats, the same as was applied to the KDW fighters. Some later machines had the engine enclosed in an egg shaped cowling. German pilots did not like the type; the CC was tricky and even dangerous to fly and unsuited to North Sea conditions. They considered it unsuitable for northern waters and, like the KDW, the day of the "star-strutter" was over and the survivors of the 36 ordered were relegated to storage at the Hage navy depot.
   Castiglione now saw the opportunity of supplying the CC flying boat to the kuk Kriegsmarine, and made a gift of a special CC to Linienschiffsleutnant Gottfried Banfield.(12) This machine differed from the German model in that it was powered by a 185-hp Austro-Daimler rather than the 160-hp Benz. This machine was initially marked CC on the hull and was allocated the serial A12.(13) Banfield reportedly shot down an Italian Farman over the Sdobba Estuary only a week after he received the CC but this was not officially credited to the ace. He was credited with one victory while flying A12, a Caproni Ca.I on 3 December 1916, for his eighth official victory. Banfield recorded that two Caproni bombers, escorted by two Nieuports, approached Dottugliano and Sesana, northeast of Trieste, and he took off to engage.
   "I immediately took off in my new Brandenburg A12 seaplane fighter, the best single-seat naval fighter so far constructed, with a speed of about 200 kilometres per hour.
   "I attacked the first Caproni, which turned westward. I closed from 300 metres distance and began firing at 30 metres. Immediately injured by my fire, the rear machine gunner left his post. The enemy continued to fire, however, hitting my aircraft twice. Then the Caproni went into a dive and a half roll in the direction of Duino. The wreckage of the crashed airplane was later brought back to Trieste."
   The crew of four were all injured, two severely. The Caproni bore the serial 1233. All crew were injured, the gunner, caporale Oreste Castoldi, was killed in the encounter. The survivors were made POWs.(14)
   Known as KDW (Kampf Doppeldecker Wasser - Fighting Biplane Water) in Austro-Hungarian service (not to be confused with the German Brandenburg KDW floatplane fighter). Two batches of CC fighters were then ordered from Brandenburg by the kuk Kriegsmarine: A13-A24 on 21 October 1916, and A25-A48 on 1 November.
   Improvements were made to meet the requirements of the German and Austro-Hungarian Navies. An aerofoil type radiator replaced the car-type used on the early aircraft, the fuselage was slightly increased in length to improve directional stability, and the slight stagger was eliminated.
   The type was in action during the summer of 1917 in the North Adriatic. It proved capable of meeting the Italian Nieuport 11 biplanes and although not as manoeuvrable, was faster than its opponent. However by the end of the year their place was taken by the Brandenburg W.18, a machine with more kindly flying characteristics. One CC, A21, was still in service as late as October 1918 when the type was definitely withdrawn from service. A total of 19 CC biplanes was lost to accidents and only two to enemy action, statistics that point to the tricky flight characteristics of the little flying boat fighter.(15)
   Caught up in the triplane craze, Brandenburg produced a triplane version of the CC in 1918. The bottom wing was reduced in span and the new middle wing was even shorter in span and mounted from the junction of the "star struts" to the engine bearers. It carried the radiator in the upper wing, indicating it was based on a late model CC. The wing span is stated to be 9 m as against the 9.3 m of the biplane.(16) One source states that the hull was lengthened, but the dimension quoted is the standard 7.6 m. The motor was the 200-hp Hiero.(17) Given the serial A.45 it would have been received in May 1918 but was not a success and was abandoned by September. Statements that the triplane was a modification of an existing kuk Kriegsmarine boat rather than a new machine have not been confirmed; however, The Typenschau lists the triplane as the Phonix Dr.I..

(11) For some reason the CC was noted as an Ago aircraft in the Allied press, the Italians apparently calling the Austro- Hungarian fighter seaplane an Ago well before 1918. An article in L'Aerophile for 1-15 November 1918,contained an article with a drawing of the CC but termed an Ago flying boat. (See "Austrian Naval Aircraft", Cross & Cockade Journal, US,Vol.7 No.2, P.116.)
(12) In his autobiography Heinkel states that he designed the CC specifically for Banfield at Castiglioni's request.
(13) The A Class was developed as the K Class could not defend itself from the rear. It was realized that a single-seat fighter was required as escort. The last year of the war saw the fighter seaplanes replaced by landplane fighers, the Phonix D.I and D.II.
(14) Banfield, G. "Air War in the Adriatic - A Memoir of Gottfried von Banfield," translated by P. Kilduff. Cross & Cockade Journal, USA, Vol.14 No.1,1973. P.49.
(15) Ciglic, B. Seaplanes of Bocche, Jeroplanae Books, Serbia, 2014. P.64.
(16) Schupita, P. Diek.u.k. Seeflieger, Bernard & Graefe Verag, Austria, 1983. P.77.
(17) The Typenschau lists the triplane as having a 185-hp Austro-Daimler.


Type CC Orders for the German Navy
Marine No. Class Delivered Notes
946 E Feb 1916 Prototype.
1137 - 1146 E2MG April-May 1917
1327 - 1351 E2MG May-Aug. 1917 Extra interplane struts.


Brandenburg CC Specifications
Source Typenschau Brandenburg Typenschau Phonix KDW Gray & Thetford MN 1137 - 1146 SVK MN 946 SVK MN 1341 Brandenburg 3-View George Haddow Data
Dimensions in m
Span, Upper 9.30 9.30 9.3 9.300 9.300 9.300 9.3
Span, Lower 8.74 8.74 - 8.740 8.740 8.740 8.74
Chord, Upper 1.650 - - 1.650 1.650 1.650 1.65
Chord, Lower 1.650 - - - 1.500 1.500 1.5
Gap - - - - - 2.000 2
Length 9.15 9.15 7.69 7.650 9.100 7.690 7.65
Hull Length 7.14 - - 7.140 8.450 7.14 -
Hull Width 1.00 - - - 1.000 - -
Height, m - - - - - - 3.2
Areas in m2
Wings 26.50 26.50 26.52 - - 26.52 26.5
Ailerons 1.80 - - - - 1.76 -
Elevators 1.15 - - - - 1.15 -
Rudder 0.54 - - - - - -
Weights in kg
Empty 801 801 716 - - 716 716
Loaded 1,081 1,081 1,031 - - 1,031 1,030
Performance
Speed in km/hr 160 160 175 - - - 170
Time to 800 m 4 minutes 4 minutes - - - -
Time to 1000 m 5 minutes - 5 minutes - - - 5 minutes
Time to 1500 m 8.5 minutes - - - - -
Time to 2000 m 13 minutes - - - - - 11.2 min.
Motor 160-hp Austro-Daimler 185-hp Austro Daimler - - - 150-hp Benz 185-hp Austro Daimler


Type CC Orders for the kuk Kriegsmarine
Serials Notes
A12 185-hp Austro-Daimler
A13 - A24 160-hp Hiero/180-hp Hiero/200-hp Hiero. A14 - A17 were fitted with 160-hp Hiero engines due to shortage of the 180-hp Hieros.
A25 - A48 200-hp Hiero/200-hp Austro-Daimler. From A31 on twin guns & improvements similar to German Navy requirements were added.
  


Type W.21 & W.22
  
   It is thought that this was an experimental machine to test the new hull but no data are available.These were projected flying boats with the 80-hp Oberursel rotary engine. Their tie in to Marine Numbers is unknown; however the use of the 80-hp rotary engine would indicate that these were in the Class Bu. A printed list "Hansa-Brandenburg, 1914-1919", source unknown, lists the W.21 as a reconnaissance aircraft, and the W.22 as a fighter flying boat with a 200-hp Hiero engine.


Type W.22
  
   It is thought that this was an experimental machine to test the new hull but no data are available.A Brandenburg flying boat identified as the W.22 was a single-seat pusher flying boat with the "star-strut" layout of the later CC boats with the additional V-struts supporting the wing overhang. What is unusual about this boat is the hull had oval-shaped sponsons each side. It is thought that the machine was an experiment to see what benefit the addition of sponsons would have to the flying boat. The machine may have been a modified CC but further details, including its Marine Number if it had one, are lacking. The following specifications have not been confirmed.(21) The W.22 has also been identified as a projected flying boat with the 80-hp Oberursel rotary engine and is discussed below.

(21) Specifications from Gutschow, F, Die Deutsch Flugboote, Motorbuch Verlag, Stuggart, 1978.

Type W.22 Specifications
Span upper/lower 9.30/8.75 m
Length 9.15 m
Weight 1170 kg
Speed 200 kph
Engine 200-hp Mercedes


Type W.31

   This is listed in Brandenburg records as a "Windtunnel Model" of a flying boat. Why this designation was applied to a model is not known. Brandenburg was developing a piloted model of a giant (R-Type) flying boat and this may have been the W.31.

Type GW
  
   According to Heinkel, the GW floatplane was based on the twin-engined GF bomber. The family development is readily seen in the appearance of the machine. This large floatplane was developed during 1916 to carry a 725-kg torpedo, hence T Class. The prototype, MN 528, had triple vertical tail surfaces but this was simplified on production machines. The drag-inducing frontal radiators of the prototype were replaced by flush-mounted aerofoil radiators on the rest of the batch of floatplanes. Heinkel states it was the first time that a machine carried starting devices for the engines.(35) One defensive Parabellum machine gun was provided. The prototype passed its tests in January 1916 at Warnemunde. The German Navy ordered a further 20 of these aircraft after successful testing of the prototype.
   The twin Mercedes engines were mounted in nacelles between the wings on each sides of the fuselage. The rudder was balanced being above the fin and below the fuselage. A large triangular fin was mounted atop the fuselage. The twin floats were mounted directly below each engine nacelle. A single machine gun was provided for defence.
   The first two batches of five machines each were delivered between April and August 1916. The production examples were mainly operated from Lake Engure,(36) Angernsee seaplane station in Courland, Latvia, against Russian targets. The German army had captured large areas of the Russian Empire in 1915. The seaplane base established at Angernsee was to enable the Germans to carry out reconnaissance and aerial operations against the Russian forces on the Eastern and Southern sides of the Gulf of Riga. The lake was an excellent place from which to operate seaplanes and a nearby airfield allowed for the use of landplanes as well, Fokker Eindecker monoplanes operating from here in defence of the station. In July 1916 the 1st Torpedo-Staffel began to establish itself at the station with a single Friedrichshafen FF33H and four Brandenburg GW floatplanes. The Brandenburgs were numbered T1 to T4 and these numbers were carried on their fuselage.
   T3 (MN 648) was damaged during a Russian air raid on 16/17 August. Its tail was damaged when a Russian bomb blew the hangar door in. T1 and T4(37) also sustained slight shrapnel damage during this attack.
   Apparently the GW floatplanes were not well received as it was reported back to the test command that it took over an hour to reach cruising altitude.
   Although each batch was different they were all designated Type GW and were duly recorded as such in the SVK drawings. The prototype had triple rudders. MNs 700 - 704 had a more rounded nose and a single rudder. This batch was constructed between September 1916 and January 1917. MNs 1080 - 1084 had short noses and were constructed between September and November 1917. They saw service from Zeebrugge and other North Sea bases.
   The kuk Kriegsmarine received a single GW (MN 701) in late November 1917 that received the Austro-Hungarian serial T1 (T2 and T3 were Gotha WD.14 biplanes).

(35) Various writers have noted that Heinkel had a habit of claiming the "first" for many innovations.
(36) Also spelt Angern. This section has been written mainly from "The Battle of Angernsee", by A. Alexandrov and R. Kintner, Over the Front Journal, US, Vol.18, No.4, 2003, P.292.
(37) T4 was MN 649.


Brandenburg GW Production
Marine Numbers Class Delivered Notes
528 T Jan. 1916 Prototype. Triple rudders.
620 - 624 TMG Aug. - Oct. 1916 Machine gun provided for defence. Revised tailplane, triple rudders.
646 - 650 TMG Apr. - July 1916 Transition between triple & single rudders in this batch.
700 - 704 T Nov.1916 - Mar.1917 Single rudder. Gunner to rear. 701 to Austro-Hungarian Navy.
1080 - 1084 T Sept. - Nov.1917 Revised tailplane, balanced elevators.


Brandenburg GW Specifications
Source Typenschau Gray & Thetford Brandenburg 3-View GW IV Serie SVK MN 620 (620 - 624) SVK MN 647 (646 - 650) SVK MN 700 (700 - 704) SVK MN 1083 (1080 - 1084)
Dimensions in m
Span, Upper 21.56 21.56 21.560 21.000 21.000 21.000 21.560
Span, Lower 21.56 21.56 21.560 21.000 21.000 21.000 21.560
Length 11.74 11.74 11.700 11.700 11.740 11.900
Chord, Upper 2.56 - 2.560 2.400 2.400 2.500 2.560
Chord, Lower 2.56 - 2.560 2.400 2.400 2.500 2.560
Areas in m2
Wings 103.40 103.4 - - - - -
Ailerons 6.0 - - - - - -
Elevators 2.5 - - - - - -
Rudder 2.13 - - - - - -
Weights in kg
Empty 2,374 2,374 2,334 2,399 2,315 2,361 2,374
Loaded 3,856 3,856 3,928 3,590 3,741 3,787 3,856
Performance
Speed in km/hr 127.5 127.5 - - - - -
Time to 500 m - - - 9.9 min. 10.5 min. 9 min. 11.7 min.
Time to 800 m 20.9 min. 20.9 min. - 17.5 min. 21 min. 14.5 min. 20.8 min.
Time to 1000 m 29.1 min. 29.1 min. 22 min. 26 min. 30 min. 19.9 min. 29.4 min.
Time to 1500 m - - - 53.5 min. 60.5 min. 34 min. -
Motor 160-hp Mercedes 160-hp Mercedes D.III 160-hp Mercedes 195-hp 195-hp 160-hp 160-hp Mercedes


Type GDW
  
   As the designation shows, the Class T floatplane GDW was a development of the GW designed to carry the heavier 825-kg torpedo, the extra power being supplied by a pair of 220-hp Benz engines. Only a single aircraft, MN 746, was built. The prototype was modified after its acceptance by the SVK as photographs show that the rudder was now an inverted L shape and did not extend below the fuselage. A large triangular fin was fitted. The elevators were now balanced and in two pieces. The SVK drawing shows MN 746 with plain elevators and a large rudder with balance surfaces above and below the fuselage. The machine must have been modified after initial testing. Again a single machine gun provided defence. The pilot and gunner were both situated towards the wing trailing edge, in close proximity for communication. The pilot would have had little view above due to being situated almost completely below the upper wing. The wings were constructed in seven sections, the outer panels being swept back from the engine nacelles.
   It is thought the GDW was utilized for training as no further development took place. Production of such large aircraft in small numbers was typical of the times. Aircraft were constantly evolving and the skilled factory workers could produce a prototype in a relatively short time. Until a machine had flown there was no way of knowing if the design would perform as predicted by the aeronautical engineering science of the day.

Brandenburg GDW Specifications
Source Typenschau Gray & Thetford SVK MN 746
Dimensions in m
Span, Upper 24.30 24.5 24.500
Span, Lower 24.30 - 24.500
Length 9.50 9.5 9.500
Height - 5.0 5.000
Chord, Upper 2.935 - 2.935
Chord, Lower 2.935 - 2.935
Areas in m2
Wings 134.00 134 -
Ailerons 9.0 - -
Elevators 3.40 - -
Rudder 2.85 - -
Empty Wt., kg 2,950 2,936 -
Loaded Wt., kg 4,865 4,851
Performance
Speed in km/hr 130 130 -
Time to 800 m 13.5 min. - -
Time to 1000 m 17.5 min. 19.5 min. -
Time to 1500 m 29.0 min. - -
Time to 2000 m 45.0 min. - -
Motor 220-hp Benz 200-hp Benz Bz.IV 200-hp Benz

Type KDW

   The Brandenburg KD (D.I) land based fighter was the basis of the KDW single seat fighting floatplane. The floatplane retained the "star struts" of the KD; in fact the prototype was virtually a KD fuselage mounted on floats with wings of slightly increased area. The KDW was designed due to a requirement for a naval air station defence fighter.
   The fuselage followed the construction of the KD with four spruce longerons, ply formers forward, spruce spacers and transverse diagonal bracing members aft the cockpit and ply covering, eliminating the need for internal wire bracing. Metal panels enclosed the engine. The fuselage was deep and tapered to a vertical knife edge. A synchronised Maxim 08/15 machine gun was mounted on the starboard side. Initially this was mounted too far forward for the pilot to be able to rectify a jam while in flight. On later machines it was mounted within reach of the pilot. The fin was ply covered, while the tail surfaces were of metal tube with fabric covering.
   The horizontal tailplane was mounted on the longerons and braced by steel tubes to the lower longeron. The parallel chord elevators were of steel tube and fabric covered.
   The KDW proved as difficult to fly as its landplane counterpart. It was necessary to increase the fin area below the fuselage, and an upper fin had to be added as well. The machine had poor directional stability due to the deep fuselage blanketing the rudder and spin recovery was marginal, "more by luck than by any degree of skill."(38)
   The prototype received the MN 748, and five batches were constructed as noted in the table, for a total of 58 aircraft. The prototype and early production aircraft up to MN 1076 were fitted with the 150-hp Benz and a nose mounted radiator. On 27 June 1917, flying on all Brandenburg KDW and CC fighters was forbidden until an additional pair of light tubular struts supporting the wing overhang were fitted, thereby obviating the benefit of the star-strut arrangement. This modification was standard on the last two batches. The aircraft from the first, third and fourth batches were fitted with the 160-hp Maybach Mb.III engine and an aerofoil radiator mounted in the wing to starboard of the centre line. The Maybach powered examples can be identified by their single exhaust manifold on the starboard side. Aircraft of the second production batch had either the 150-hp Benz Bz.III if intended to serve in the Baltic, or, if intended for the North Sea and Flanders, the 160-hp Mercedes D.III. The selection of engine provides a statement as to what area was considered the greater threat to the seaplanes.
   The German Navy found the "star-strutters," both the KDW and CC, heavy, tricky and unsafe to fly. The view from the cockpit of the KDW was poor, making it unsuitable for air fighting as the risk of a collision was constant. The type was known as the "Spider" in service due to the unusual strut arrangement. The survivors of the 58 KDW fighters were stored at the Navy Depot at Hage.
   KDW fighters MNs 1571 - 1573 were to go to Turkey but were instead sent to the Seddin depot. One KDW is reported by Turkish sources to have been used by the Ottoman air force as a maritime reconnaissance machine. When it arrived it had no armament and was powered by a Mercedes engine. KDW MN 1557 was sent to Japan post-war. The Japanese showed more interest in the Brandenburg floatplanes than any of the Allied powers, even receiving Austro-Hungarian Brandenburg C.I biplanes.


Service use of the KDW(39)

   Prototype MN 748 was flown to Angernsee where it was to be tested under actual service conditions. Here the Germans were facing the Russians. Sikorsky bombers that, together with other aircraft, carried out attacks against the German base. MN 748 commenced its first mission on 12 September 1916, as escort to torpedo bombers. On 23 September MN 748 was in the hands of Ltn.d.R. Fritz Hammer when he intercepted one of the giant Sikorsky bombers and after making four runs at the bomber, Hammer succeeded in forcing it down near a forest near Dunamunde. During the combat Hammer had been caught up in the turbulence from the Sikorsky's engines and had nearly lost control of his small floatplane, a type not known for its stability.
   On 12 February 1917, Zeebrugge had the following Brandenburg aircraft out of a total of 53 aircraft on strength:
   KDW: MNs 912 - 916, and 1067 - 1068
   W.11: MNs 988 - 990
   CC: MNs 1137, 1139, 1141, 1143, and 1145
   W.12: MNs 1014 - 1015
   The superlative W.12 would replace the obsolescent KDW in the fighter role.
   The 28 March 1918, was not a good day for the KDW fighter-trainers of the floatplane school at Putzig. KDW fighters MNs 1385 and 1072 were part of a group of three when they collided. The KDW had been criticized for the lack of visibility from the cockpit, particularly when trying to fly in formation. MN 1385 cut off the tail of MN 1072 that crashed, killing the pilot. MN 1385 also crashed but the pilot survived. The third KDW, MN 917, also crashed trying to avoid the other two and although destroyed, the pilot survived. This was not the end of the saga as MN 915 took off to assist the machine side-slipping out of a turn at 100 metres and crashing, again destroying the aircraft but the pilot managing to survive. The pilots owed their survival to being picked up by local fishing boats. The school did not have a fast motor launch and the unit's diary recorded this fact.
   As a result all KDW training was cancelled, the machines being grounded. As the current course could not be completed without these machines the ban was soon lifted and the KDW floatplanes were soon flying, and crashing, again. However, not all the blame could be levelled at the Brandenburg as Albatros W.4 and Rumpler 6B2 biplanes also contributed to the statistics. In the period of one month eight single-seat floatplanes had been destroyed or seriously damaged, five of them being KDW fighters with three deaths on the Brandenburg machines. It appears that the school continued to use the Brandenburgs till at least July, with one, 1387, being shipped from there to Hage in early November.
   Given the small number of marine aircraft built for the German Navy, the KDW was a reasonable success. The competing Albatros W.4 floatplane based on the D.I biplane fighter was built in double the numbers of the KDW, had a better performance, and was a better fighting machine due to its speed and the view from the cockpit.
   The British confidential Types of German Seaplanes and Flying Boats of July 1918, contains photographs and silhouettes of the KDW wherein it is described as "Brandenburg Seaplane 1917." Apart from stating that the machine was powered by a 150-hp Benz or 160-hp Maybach, no other technical information is described. A second entry repeats the description but states the motor is a 200-hp Benz and it is apparent that the aircraft is the W.11; however, it is illustrated with photographs of a machine bearing MN 508. This Marine Number was assigned to a Friedrichshafen FF33E. This error was repeated for the Type NW. As the photographs have been copied from a German publication the question arises if they were designed to mislead the Allies, yet the photograph of the Type GW show MN 700 and correctly identifies the engines as 160-hp Mercedes.

(38) Gray, P. & Thetford, O. German Aircraft of the First Word War, Putnam, UK, 1962.
(39) This section is based on the pioneering work of Ron Kinter. See "The Brandenburg KDW Operational History," Over the Front Journal, Vol.24, No.3, P.217.


Brandenburg KDW Production
Marine Numbers Class Engine Delivered Notes
748 ED 150 Bz.III Sept. 1916 Prototype. Completed Sept. 1916
783 - 784 ED 150 Bz.III Sept. 1916 Prototypes. Completed Sept. 1916
912 - 921 ED 160 Mb.III Jan. - Feb. 1917 Completed Feb. 1917
1067 - 1076 ED 160 D.III/ 150 Bz.III Oct. 1917 - Apr. 1918 Completed in Mar. & Apr 1917. Aircraft for North Sea had Mercedes. Aircraft for Baltic had Benz.
1380 - 1394 ED 160 Mb.III Mar. - Aug. 1917 Additional interplane struts as standard.
1554 - 1573 E2MG 160 Mb.III One or two machine guns. Completed between Oct. 1917 &. Feb. 1918. Additional interplane struts.


Brandenburg KDW Specifications
Source Typenschau (see note) Gray & Thetford SVK MN 784 SVK MN 914 SVK MN 1067 SVK MN 1554 Brandenburg 3-View
Dimensions in m
Span, Upper 9.30 9.25 9.300 9.300 9.300 9.250 9.300
Span, Lower 9.30 - 9.300 9.300 9.300 9.250 9.300
Chord, Upper 1.655 - 1.650 1.650 1.650 1.650 1.650
Chord, Lower 1.655 - 1.650 1.650 1.650 1.650 1.650
Length 7.86 8.0 8.000 7.900 7.900 8.000 7.860
Height - 3.35 3.150 3.370 3.370 3.350
Areas in m2
Wings 29.15 20 - - - - -
Ailerons 1.85 - 1.85 1.85 1.85 1.74 -
Elevators 1.10 - 1.08 1.10 1.10 1.10 -
Rudder 0.64 - 0.65 0.64 0.62 0.53 -
Weights in kg
Empty 759 940 768 759 775 940 768
Loaded 1,039 1,210 1.048 1,059 1,065 1,210 1,048
Performance
Speed in km/hr 172 170 - - - - -
Time to 800 m 3 min. - 4 min. 3 min. 3 min. 4.5 min. -
Time to 1000 m 4 min. 5.9 min. 4.5 min. 4 min. 4 min. 5.9 min. 4.5 min.
Time to 1500 m 6 min. - 7.5 min. 6 min. 7 min. 9.5 min. -
Time to 2000 m 9 min. 14 min. 11 min. 9 min. 11 min. 14.9 min. 11 min.
Time to 3000 m 16 min. 21 min. 21.5 min. 16 min. 22.5 min. 21 min. 21.5 min.
Endurance - 2.5 hour - - - - -
Motor 160-hp Maybach/150-hp Benz 150-hp Benz Bz.III/160-hp Maybach Mb .III 150-hp Benz 160-hp Maybach 150-hp Benz 160 Maybach 150-hp Benz
Note: The Typenschau specifications are for a machine with a single machine gun.

Type W.13 (Austro-Hungarian K Flying Boat)

   The W.13 was another large flying boat built for production in Austro-Hungary by Phonix and UFAG, and later by Oeffag, as a Type K boat.(5) The prototype was constructed in Germany but none were used by the German air services.
   The first W.13 for the kuk Kriegsmarine was K305 that arrived at Pola in March 1917. This machine crashed on 25 April during trials. The second Brandenburg-built machine, K306, did not arrive until 6 March 1918, indicating problems at the Brandenburg factory at Briest. In the meantime the type had entered active service, with K366 attacking the Italian barracks at Palmanova in August 1917.
   K307 was found by an Italian Torpedo boat on 28 September 1917, having alighted due to engine failure, and was recovered in almost perfect condition. "She appeared to be brand new, well-built, and nicely finished off, a great contrast to K222, captured on 11th August 1917, which was rather cheaply built." The report published by the British noted that the wings were of deep section and large camber. The interplane struts were of 44 mm streamlined steel tubing and inclined inwards from bottom to top. The fin was a hollow three-ply structure built onto the hull that was constructed of three-ply throughout.
   The wings were attached by steel extensions of the main spars that passed through the deck of the hull. The pilot sat on the left side with the observer on the right. He could pass to the front cockpit by means of a sliding door without climbing over the top. The engine was reported to be a 12-cylinder Vee-type Austro-Daimler of 345-hp. Twin Bosch magnetos were fitted, each supplying 12 cylinders. Twin carburettors were fitted on the starboard side, each supplying six cylinders. Starting was achieved by means of a starting crank (removable) on the end of the crank shaft and a standard Bosch starting magneto. The engine was supported on steel bearers.
   The two-bladed propeller had brass tips and was of mahogany except for the central lamination that was of ash. Fuel for eight hours was carried in two tanks located in the hull under the engine. The forward tank held 170 litres, while the aft tank held 590 litres. A gravity tank located in the starboard top plane was fed by air pressure from the main tanks. Full supply also could be made from the main tanks. A hand pump and two mechanical pumps driven off the cam shaft could be used to supply fuel.
   The aileron controls were led from the hull through the wings. Rudder and elevator control runs were along the top of the boat. No controls were duplicated. "The rudder control bar is fitted with rests for both feet, and must be unusually comfortable for a long flight."
   Armament comprised a single machine gun in the front cockpit, the gunner standing to operate the gun. K307 was fitted to carry two 155 kg bombs and fourteen 20 kg bombs. One 155 kg bomb was carried against the hull under the main planes on each side. The bombs could not be released except in a live condition as the fusing wire was operated by the bomb-dropping lever. Fourteen 30 kg bombs could be carried in two "more or less" streamlined boxes mounted on the lower main planes. The bombs could be dropped separately or by turning the lever swiftly, in a box together.(6)
   Despite the "Kappa" having a good record in service, 59 of the 134 known to have been constructed were placed directly into storage, mainly due to the lack of suitable engines.
   After the end of the war, when the French left the Austro-Hungarian seaplane base at Kumbor, the Royal Yugoslav Navy obtained 22 abandoned Austro-Hungarian marine aircraft. There were four Brandenburg W.18 flying boats, five Brandenburg K, and five Brandenburg W.13 boats, together with a Friedrichshafen FF49C, two Rumpler 6B2 floatplanes, and five Lohner TL boats. Some of these, including the Brandenburgs, were pressed into service, mostly as trainers.(7)
   The USN received a number of Austro-Hungarian naval aircraft post-Armistice. On 23 October 1919, it was reported that the Commander, US Naval Forces, Eastern Mediterranean, had arranged with Italian authorities to obtain two ex-Austrian seaplanes from the Naval Air station at Pola. UFAG-built W.13 K405, with a 12-cylinder 450-hp Daimler engine, was shipped to the US by the USS Mars in October 1919, along with UFAG-built FB K248 with a 250-hp Hiero engine,(8) both boats being reported at the Naval Aircraft Factory (NAF) on 1 October 1920. K405 was restored to flight status with a Liberty engine by the NAF. On 4 January 1921, it was reported that the bottom of the hull was weak and old and should be replaced. Whether this was done or not is unknown; however, the flying boat was shipped by air to Hampton Roads, where the USN had its experimental facility, on 27 May 1921. It underwent testing at Hampton Roads with the Bureau No. A-5806. On 18 May 1922, Hampton Roads put in a Trouble Report that noted that the hull had depreciated to such an extent that the machine was no longer safe to fly and as it was beyond economic repair, it was recommended that it be stricken from the list of naval aircraft, this being carried out on 16 June 1922.

(5) The K class of flying boat was introduced to supplement the L Class and to have a greater load and defensive power with a crew of three and a machine gun in the forward cockpit. The types were most often flown with a crew of only two.
(6) UKNA AIR1 /716/27/19/32. "Austrian Flying Boat"K.307."
(7) Why the W.13 boats were listed separately from K boats is not explained. Source: Isaic,V. and Frka, D. Naval Aviation at the Eastern Coast of the Adriatic Sea 1918-1941 (Volume 1), TKO ZNA ZNA, Zagreb, 2010.
(8) NARA RG72 Box 2, File O-ZS-21.


Brandenburg W.13 Production
Serial Manufacturer Notes
K305 - K319 Brandenburg Short hulls. 350-hp Austro-Daimler.
K320 - K364 Brandenburg Long hulls. 350-hp Austro-Daimler. 40 delivered without engine.
K365 - K422 UFAG 350-hp Austro-Daimler. K417 - K421 destroyed in fire at factory.
K425 - K452 Phonix Long hull. Only first 10 delivered, 7 without engine (See below).
K431 & K434 Oeffag 350-hp Austro-Daimler. Possibly sub-contract from Brandenburg.

Type W.16

   The little W.16 station defence fighter of pleasing lines was constructed in 1916. Unusually for a Brandenburg floatplane design it was powered by a rotary engine, the 160-hp Oberursel U.III. Of conventional Brandenburg-type construction, it featured "V" interplane struts with another strut from the lower wing to the fuselage, thereby doing away with cable bracing. Three were ordered (MNs 1077 - 1079) but MN 1078 was reportedly cancelled; however, all three were recorded at Warnemunde according to a report of 15 May 1917; and MN 1078 was recorded at the Hage Repair Depot in November 1919. No flying records of these aircraft have been found in the war diaries to date.
   While flying characteristics were probably an improvement over the KDW, its speed of 170 km/h was the same, and above 1,000 m its climb was inferior. The type therefore had no chance of a production run, especially as the W.12 was greatly superior.
  

Brandenburg W.16 Specifications
Source Typenschau Gray & Thetford Brandenburg 3-View SVK MN 1078 (1077 - 1079)
Span, m 9.11/7.77 9.25 9.110/7.774 9.250/7.800
Chord, m 1.6601.100 - 1.650/1.100 1.660/1.110
Length, m 7.35 7.35 6.845 7.350
Height, m - 2.925 - 2.925
Areas, m2
Wings 23.00 21.35 23.0 21.35
Ailerons 1.45 - - 1.45
Elevators 1.0 - - 1.00
Rudder 0.40 - - 0.40
Empty Wt, kg 659 636 659 636
Loaded Wt, kg 935 896 935 896
Performance
Speed in km/hr 170 179 - -
Time to 500 m - - - 3.9 minutes
Time to 800 m - - - -
Time to 1000 m 5 minutes 5 minutes - 5 minutes
Time to 1500 m 8.2 minutes - - 8.2 minutes
Time to 2000 m 12.6 minutes - - 12.6 minutes
Time to 3000 m 27 minutes 27 minutes - 27.0 minutes
Endurance - 2 hours approximately - -
Engine 160-hp Oberursel 160-hp Oberursel U.III - 160-hp Oberursel


Brandenburg W.16 Production
Marine Numbers Class Engine Notes
1077 - 1079 ED Oberursel U.III 1078 reportedly cancelled 15.11.18. 1079 static test November 1918.

Type W.12
  
   The KDW and Albatros W.4 single-seater fighters performed well for their day, but were obsolescent by the end of 1916 and the Naval authorities had already determined to concentrate their limited raw materials to the development of two-seat fighter floatplanes that would be defended from the rear. The English were experimenting with the Curtiss America flying boats and the first Large America boat, the Curtiss H-8 serial 8650, arrived at Felixstowe for erection on 24 March 1916. The machine required much modification and the improved type, designated H-12, started to enter service at the end of the year, therefore the W.12 was not designed to counteract the Large America flying boats as has been suggested in some publications. The British Short floatplanes on anti-submarine patrols from Dunkirk were escorted by Sopwith Baby fighters. By May 1917 the Dunkirk seaplanes were unable to undertake meaningful work due to the opposition by German fighting aircraft, and it was suggested that the Baby seaplanes be replaced by fighter land planes.
   A combat on 19 June 1917, with Short 184 serial 9057 and its two escorting Sopwith Baby fighters of the Dunkirk Seaplane Squadron, emphasized the change in conditions. The British aircraft set out on a mine and U-Boat spotting patrol. When half an hour out and about 12 miles north-east of Dunkirk they were attacked by three enemy fighting seaplanes. Flt. Sub. Lt. J.E. Potvin in Baby N1015 was shot down by the German pilot Dyck, who was himself brought down with an abdomen wound when attacked by Flt. Lt. R. Graham in the other Baby. In the meantime the observer in the Short, Lt. T. Rogers, had been shot and killed by another of the attacking Germans. The Short's radiator and fuel tank had been hit, forcing the floatplane to alight. Graham's Baby was badly shot about and he was forced to leave the action with a failing engine. He alighted alongside a French destroyer and sent two messages by pigeon to Dunkirk. Graham wrote that the Short had been shot down and "Potvin?" His tank had been shot and he couldn't climb. He requested that more fighters be sent.
   Dyck had managed to alight safely and one of his companions landed alongside and removed the wounded pilot to his own single-seat fighter and succeeded in reaching Ostend, but in vain, as Dyck had died on the way. A thunderstorm meant that Dunkirk could not send out any aircraft and the decision was made to send out two of the then secret Coastal Motor Boats (CMB) as speed was essential. One of the boats suffered engine problems and was captured by the Germans. The other had an eventful cruise, being attacked by four enemy destroyers, and after firing a torpedo, unsuccessfully, returned without seeing anything. It was afterwards learned that German destroyers had reached the Short and taken aboard her pilot and dead observer. This episode resulted in the loss of two seaplanes and one of the new CMB vessels, and emphasized the need for first-class fighter aircraft to oppose the German seaplanes. The Baby seaplanes were replaced by Sopwith Pup fighters and later by Sopwith Camels when the Flight was expanded into the Seaplane Defence Squadron (later No.13 Squadron, RNAS).
   The first Brandenburg floatplane fighter to achieve fame, the W.12 exhibited characteristics that the late P.M. Grosz noted were inherited from the development of the Brandenburg Type K and KDD landplanes built for the Austro-Hungarian LFT. These characteristics were the high-sided fuselage with rudder under the tailplane giving the rear gunner an unparallel field of fire without danger of damaging his own aircraft. The Castiglioni group of companies shared information and it is probable that the fuselage design of the prototype that became the W.12 was influenced by the design efforts in Austro-Hungary that led to the Phonix and UFAG C.I reconnaissance two-seat biplanes.
   Heinkel states that he designed the W.12 in eight weeks. Heinkel was the Chief Designer but was not alone in working on the design. He states in his autobiography that he had to work hard to achieve the light, strong structure in order to meet the performance specification with the then available engines.
   The W.12 was designed in 1916 as a seaplane defence fighter having a gun for rearward protection. The German Navy placed an order for three W.12 prototypes on 15 October 1916, (MN 1014 - 1016). This was followed the next month by another order for three further prototypes (MN 1011 - 1013).(41)
   The W.12 was of conventional Brandenburg construction but possessed design characteristics that were to be carried forward through to the next models of Brandenburg fighters and to influence other manufacturers. The fuselage was based on four spruce longerons with multi-ply formers supporting the engine. The pilot was located behind the engine seated over the fuel tank. Immediately aft of the engine bearers the longerons swept up towards the tail giving an elevated gun position for the observer. The observer's cockpit was surmounted by a metal basin shaped structure containing the gun ring. This allowed plenty of room for handling the gun. He could fire his LMG 14/17 Parabellum machine gun over the wing and, if necessary, through the wings without concern that he would cut the bracing cables as the structure did not require any cables. The fuselage tapered to a vertical knife edge. The cantilever horizontal tailplane was ply covered and mounted flush with the upper longerons, well clear of spray. The tailplane was thicker at the centre and air flow disturbance caused the steel tube elevators to be redesigned. The cantilevered tailplane meant that the gunner could aim his gun close to the fuselage without tailplane bracing struts entering his field of fire. The elevators were welded metal framed steel tube with fabric covering as were the rudder and ailerons. The rudder was mounted on the stern post with the balance section underneath the fuselage. The deep fuselage compensated for the additional float area and lack of a fin. The fuselage was of usual Brandenburg construction and covered with ply eliminating the need for internal wire bracing. Easily detachable metal panels forward enclosed the engine. Those machines equipped with the 160-hp Mercedes D.III engine had a leading edge radiator whilst the batches equipped with the 150-hp Benz Bz.III had a radiator mounted in the nose.
   The wings were of conventional construction but were of a thick aerofoil section in order to be strong enough to eliminate the interplane bracing cables. Both wings were of the same chord, tapering towards the tips. The upper wing was slightly longer than the lower wing. The wings were constructed around two spars, the upper wing being in one piece. A cut-out in the trailing edge gave the observer clear upward vision although this had to be enlarged on production machines. Plain unbalanced ailerons were carried on the top wing only. Later machines had ailerons on all wings connected by a link strut.
   A compass of the liquid type with floating dial of about 110 mm diameter was mounted in the lower wing about 900 mm from the side of the fuselage. In some cases it was illuminated with a small electric bulb protected from the front, the wiring for which was carried out from the fuselage through the wing. An air speed indicator of the cup type was often mounted on an interplane strut.
   The single step floats were of wood being composed of five water tight compartments and covered with marine ply. Bituminous paint was often used as a finish to make them watertight. A chassis of steel tube struts, in the form of the letter "M" in front view, connected the floats to the fuselage, the points of the "M" being located at the roots of the wing spars. Additional struts brace the floats to the wings under the interplane struts completed the structure. These formed the letter "N" in side elevation. The struts were steel tubes faired with light veneer. The ends of the struts were fitted with a screw plug that would have been used to align the machines. These struts formed a strong, robust structure that helped support the wing cellule without having to resort to cable bracing. This system of support struts was to be carried through the W.19, W.29, W.33, W.34 and proposed W.37, and was seen on the Heinkel He.1 post-war floatplane.
   The W.12 was not an instant success. As the waters round Brandenburg were frozen, the machine was crated and shipped to the seaplane test unit at Warnemunde for its first flight. Heinkel records that the test pilot was named Walter Stagge. On its first flight the W.12 proved dangerously tail heavy, and the observer had to throw all ballast out in order to allow the machine to make a safe alighting. The floatplane had to be re-rigged before the Navy personnel were allowed to fly it.(42) MN 1014 had arrived at the SVK in January 1917 but was later wrecked in an emergency landing, having to be rebuilt and was returned to testing in June 1917. Initial testing was promising, the machine possessing a good turn of speed and manoeuvrability. Before the prototypes had flown an order had been placed for ten production W.12 fighters. These machines had round wingtips as against the prototypes square tips.
   As the W.12 was developed many improvements were tried and introduced into production batches. Later aircraft had four ailerons connected by a link strut that gave improved flight characteristics. A longer fuselage was introduced from MN 2000 that significantly improved longitudinal control and the rudder was reduced in area to compensate for the additional side area. Aerofoil radiators were tried as well as a narrow tailplane; there were at least three variations of the tailplane on production machines. The wings were basically the same on all batches.
   An early criticism was made to the location of the pilot under the upper wing. In the event of an accident, his chance of getting out was hampered by the interplane struts and wing. The cut-out was made larger on the first production batch, and increased later as a reduction in stagger moved the wing backwards. Redesigning the centre-section struts to facilitate entry/exit took longer. On early production machines the upper wing was supported by five struts, the odd leg carrying the fuel pipe to the upper wing gravity tank. Later machines had a revised system of two substantial support N struts.
   The modifications that were incorporated into production aircraft were faithfully recorded on the Atlas drawings of the various batches of the W.12 as reproduced in these pages.


W.12 in Service

   German Naval activities did not involve seeking out enemy seaplanes alone, in fact reconnaissance was more important. Dr. Fritz Stormer recalled that:
   Our submarines were particularly interested in changes of the buoys set out in our sector of the sea, as well as new blockade nettings, minefields, wrecks and other underwater obstacles, all of which we were supposed to report upon our return or landing at sea. Even if we could not convey the exact nautical position we could usually mention enough recognition points to make our report essentially clear, which was especially important when we pushed as far forward as High Margate in the Thames.
   The patrols would report whether the cleared channels for access for U-Boats were kept clear. As Dr Stormer noted:
   We did more than just interdict enemy aircraft. Indeed, our mission was mainly devoted to surveillance of maritime traffic in the entire blockade sector from the English coast to Holland. On many occasions, our aircraft pursued vessels and either dropped bombs near them or signalled them to halt by directing a stream of machine gun fire across their bows, after which a German boarding party would take over. In these instances the Staffeln reported the ship’s presence by wireless telegraphy and gave the precise location. Then a large seaplane would come out with a “prize officer” who was put aboard the captured vessel while our aircraft circled overhead and observed their slow progress towards our shore. Thus many large sailing ships, as well as two steamers, did not reach their intended ports of call and were, instead, brought into Zeebrugge. One of these prizes of war served as a barrack ship for the petty officers among our flying personnel.(43)
   In line with the above activities Christiansen's Staffel was credited with the destruction of the Dutch ship Agina on 12 July 1917.
   The W.12 entered active service in the autumn of 1916. By 12 February 1917, Zeebrugge had W.12 floatplanes MNs 1014 and 1015 in service. However it was not until October that the W.12 made its combat debut. A sortie by three Friedrichshafen FF 33L, an Albatros W.4 and Brandenburg W.12 MN 1183, left Zeebrugge at 1600 (German time). After one FF33L dropped out and alighted with engine trouble, and another returned to summons help to the downed biplane, the three remaining aircraft encountered a large British flying boat and attacked.
   This flying boat was Porte Baby 9810, a three-engined machine designed by John Porte at Felixstowe. The boat was on patrol from Felixstowe in the vicinity of the North Hinder Light Vessel when attacked by "an aeroplane and two fighting seaplanes." The pilot, Flt Cmdr N. Shoto Douglas, managed to avoid many of the attacks by sideslipping, until the port and centre engine were shot up and the boat forced to alight. Once on the water the Germans attacked but AM C. Spikings kept up return fire although he had been scalded when the engine near him had been set on fire. He also worked on the engines during the night despite having burned his hands. The boat managed to taxi to the Sizewell Gap, north of Oxford, where she was taken in tow.(44) The Baby was ill designed to withstand attacks by fighter aircraft. As a result of this action the Baby was not used where enemy aircraft were expected unless an escort of America flying boats could be given.
   The Germans claimed that the British flying boat was shot down with bullets in its left engine and radiator by the W.12. The pilot, Oberleutnant zur See Friedrich Christiansen, claiming his second victory.(45) This was to be the start of the increasing activities of the Zeebrugge Brandenburg biplanes and then monoplanes against the British patrolling flying boats that lasted until the end of the war.
   "Fiede" Christiansen's name now became synonymous with the activities of the Brandenburgs from Zeebrugge. The most spectacular victory achieved by Christiansen was the shooting down the British coastal non-rigid Astra-Torres type airship C27 on 11 December 1917, off the East Anglia coast. Three aircraft took off for an offensive patrol at 0900 (German time) and over the Outer Gabbard sighted a British airship in the vicinity of the North Hinder Lightship. MN 1183 began the fight and within two minutes the airship fell some 400 metres to the sea. The crew of five perished. In actuality Christiansen was responsible for the loss of two airships. The sister airship, C26, was lost the following day while searching for the missing C27. The non-rigid drifted into Eemnes, near the Zuyderzee, after its engine failed, resulting in the crew being interned in the Netherlands.(46) As a result of this, no airship patrols were to be flown where they were liable to be intercepted by German aircraft.
   Encounters with the "Large America" Curtiss H.12 and Felixstowe F2a flying boats often turned into running battles with the flying boats flying low over the water in order to prevent attacks from beneath. The Brandenburgs would fly alongside with the gunners trading fire over the short distance separating the two adversaries. The W.12 and later W.19 would fly mixed formations with Friedrichshafen reconnaissance aircraft. When conditions were suitable the Brandenburgs would alight and wait while the aircraft with longer endurance would search for patrolling British flying boats or ships. If it saw a formation it would try and get the British to follow it to the waiting Brandenburgs, or else call up the fighters by wireless while keeping the British engaged.
   The Brandenburgs did not have everything their own way. On 1 April 1918, two W.12 floatplanes, MNs 2102 and 2107, together with a Friedrichshafen FF49C HFT Class aircraft left Zeebrugge. According to German reports they encountered six enemy landplanes and in the ensuing fight the Friedrichshafen and one W.12 (MN 2102) were shot down. The surviving W.12 shot down one enemy aircraft and returned to the station. In actuality there were only three British aircraft but they were Sopwith Camels of No.213 Squadron, the RNAS and RFC being amalgamated on that day. No British aircraft were lost. The usual accidents associated with any military air base also took their toll. On 3 April W.12 MN 1413 collided with another aircraft while alighting. Both aircraft were destroyed and the Brandenburg's pilot, Ltn.d.RMI Johns, was drowned.
   The Germans now were active in attacking the British flying boats such that instead of a lone boat the British had to send out three and eventually up to five in order to ensure that the reconnaissance was carried out. This led to a debate within the British authorities as to what was needed to combat the new German fighters. The Curtiss H.12 had inadequate armament while the Felixstowe F.2a was more heavily armed but was still vulnerable to attacks from below. The bow position carried a single Lewis gun on a Scarff mounting, the pilot had a Lewis gun on a pivot mount, and there were three gun positions behind the wings. On each side of the hull a single or double Lewis gun could be mounted on a Gallows Mount, and in the center of the hull a Lewis gun on a ring mount. An attack from the rear and below could not be engaged from any of these positions, forcing the British boats to fly low over the water in order to prevent the Germans from getting beneath them.
   The situation became so bad that a special meeting was held in May 1918 where the British stated that "in addition to the fighting seaplanes, there were the fighting aeroplanes which came up from the German coast, and it frequently happened now that a reconnaissance was not carried out because the Boats found themselves up against a superior German formation." It was stated that three boats were required if one was to win through, and it was likely that up to five boats would be needed by the end of the summer.(47)
   Christiansen added the Curtiss H.12B serial N4338 on 15 February and Curtiss H.12 serial 8677 on 24 April 1918, to his score, and claimed another Curtiss on the 25th.
   The W.12 was popular with its crews and earned the colloquial name "Kamael", probably due to the distinctive fuselage. It remained in service alongside the W.29 until the end of the war.
   The German Naval contingent in Turkey received three W.12 biplanes: MN 2018 late in 1918 and MNs 2110 and 2112 in July 1918. Nothing further is known of their activities.(48)

(41) The out of sequence of the Marine Numbers was probably due to the bureaucracy finalising the documentation and not an attempt at confusing the enemy.
(42) The top wing had to be moved backwards 350 mm. Heinkel had a works crew carry this out overnight.
(43) Dr. Fritz Stormer served in the German Imperial Navy in WWI, first in the naval infantry, then as an observer in two-seat seaplanes based on the Flanders coast. Stormer, F. "Seaplanes in Combat", Cross & Cockade Journal, USA, Vol.20, No.2, 1979.
(44) Jones, H.A. The War in the Air, Vol.IV, P.67
(45) "The Hornets of Zeebrugge", Cross & Cockade Journal, USA. Vol.11, No.1, 1970. In fact the Porte Baby made it back to the UK and was returned to service surviving until December 1918, but the type was never used in areas where opposition from German marine aircraft could be expected.
(46) C26 came down in Holland on 13 December 1917. About 03.15 four men jumped out of the gondola at Poortugaal (SW of Rotterdam), they were brought by car to Rotterdam. Between 07.00 and 08.00 the last man jumped in the Biesbosch, opposite Sliedrecht. Local workers brought him over the Merwede River. He was brought by train at 09.00 to Dordrecht. At Wijngaarden, just north of Sliedrecht, a bomb was found. C26 ended at Eemnes-Buiten, a village about 5 km from the (then) Zuiderzee, now Gooimeer and Eemmeer.The airship caused enormous damage with broken electric and telephone lines. (Research by F Gerdessen.) For several photographs of the wreck of C26 enter www.geheugenvannederland.nl and then enter "Eemnes."
(47) Forty-Fifth Meeting of the Technical Committee, 30.05.18. Copy in NARA RG72 File O-ZS-7.The Meeting was held to discuss whether the construction of a fighting flying boat was warranted.
(48) Nikolajsen, O. Op Cit.


Brandenburg W.12 Specifications
Source Typenschau Gray & Thetford Brand. 3-View*
Dimensions in m
Span, Upper 11.20 11.20 11.200
Span, Lower 10.48 - 10.480
Length 9.60 9.6 9.605
Height - 3.3 -
Chord, Upper - - 1.800
Chord, Lower - - 1.800
Areas in m2
Wings 36.20 35.3 36.26
Ailerons 9.6
Elevators 1.8 1.50
Rudder 0.75 0.75
Empty Wt., kg 1,000 997 1,000
Loaded Wt., kg 1,463 1,454 1,463
Performance
Speed in km/hr 160 159.5 -
Time to 800 m 6 min. 6 min.
Time to 1000 m 8 min. 7 min. 8 min.
Time to 1500 m 13 min. 13 min.
Time to 2000 m 20 min. 18.9 min. 20 min.
Time to 3000 m 38.5 min. 38 min.
Motor 160-hp Mercedes; 150 hp Benz 160-hp Mercedes D.III; 150-hp Benz Bz.III 160-hp Mercedes
* Date 9.3.17, MN 1011 - 1016


Brandenburg W.12 Specifications
Source SVK MN 1014 SVK MN 1185 SVK MN 1413 SVK MN 2001 (2001 - 2019) SVK MN 2023
Dimensions in m
Span, Upper 11.250 11.200 11.200 11.200 11.200
Span, Lower 10.500 10.500 10.500 10.500 10.500
Length 8.470 9.450 8.690 9.600 9.600
Height 3.230 3.550 3.300 3.300 3.300
Chord 1.800 1.800 1.800 1.800 1.800
Stagger - - 0.220 0.225 0.128
Empty Wt, kg 857 977 959 997 1,056
Loaded Wt, kg 1,314 1,434 1,230 1,454 1,550
Performance
Time to 800 m 6 minutes 7.6 minutes 5.8 minutes 5.2 minutes 8.8 minutes
Time to 1000 m 8 minutes 9.6 minutes 7.7 minutes 7.0 minutes 11.1 minutes
Time to 1500 m 13 minutes 16.2 minutes 12.9 minutes 12.0 minutes 19.7 minutes
Time to 2000 m 20 minutes 24 minutes 20.9 minutes 18.4 minutes 30.5 minutes
Time to 3000 m 38.5 minutes - - - -
Engine 160-hp Mercedes 150-hp Benz 150-hp Benz 150-hp Benz 150 hp Benz

  
Brandenburg W.12 Production
Marine Numbers Class Engine Delivered Notes
1011 - 1013 C2MG D.III Feb. - Sep./Oct. 1917 2nd order for prototypes 22 Nov. 1916. Short fuselage.
1014 - 1016 C2MG D.III 1st order for prototypes 15 Oct. 1916. Short fuselage.
1178 - 1187 C2MG Bz.III July - Aug. 1917 1st production order Jan. 1917. Short fuselage. 1181 not delivered. 1185 long fuselage.
1395 - 1414 C2MG D.III Sep. - Dec. 1917 Ordered Mar. 1917. Short fuselage. 1413 four ailerons.
2000 - 2019 C2MG Bz.III Dec. 1917 - Mar. 1918 Ordered Sep. 1917. Long fuselage, larger wing cut-out. 2016 Hispano-Suiza, later Benz Bz.IIIb V-8 engine. 2018 to Turkey.
2023 - 2052 C3MG Bz.III Mar. - May 1918 Ordered Oct. 1917. Long fuselage. 2024 used for trials of motor machine gun. 2027 destroyed during acceptance.
2093 - 2132 C2MG D.III Feb. - May 1918 Ordered Oct. 1917. 2095 nose radiator. 2110 - 2112 to Turkey.
2217 - 2236 C2MGHFT D.IIIa Apr. - June 1918 Ordered Nov. 1917. Radio fitted.

Type W.18

   The W.18 was a version of the CC single-seat fighter flying boat. One was supplied to the German Navy in December 1917, as a Class E2MG machine, with MN 2138, and a Benz Bz.III engine. The W.18 reverted to conventional interplane bracing with struts and cables. The wings were equal in chord but the lower wing was swept back. Armament was two Maxim 08/15 machine guns. The German Navy then appear to have had no interest in the machine.
   A slightly modified version with a 230-hp Hiero engine went to the Austro-Hungarian Navy. On 14 December 1916, 47 boats were ordered by the kuk Kriegsmarine. Given the serials A50 - A96, the Austro-Hungarian machines differed from the German prototype. The hull was lengthened to provide better stability, and modified to fit 8-mm Schwarzlose machine guns to the nose. The wing cellule was modified as were the tailplane and elevators. All 47 boats were delivered by the end of February 1918, and were in service in the Adriatic. A88 - A96 had been accepted without engines, probably as replacement boats, and were in service by May 1918. The problem with engine supply meant that some W.18 boats were fitted with the 200-hp Hiero.
   Phonix built a much-modified version as the Phonix A. Sixty were constructed (A61 - A120). They had a single machine gun as against the two guns of the German model. The type could take on the Italian Nieuport 11 fighters but their short endurance restricted them to operating close to the naval air stations where they were based. They were replaced by Phonix D.I landplanes when the Italians introduced new aircraft towards the end of 1917. The Phonix D series was developed from the Brandenburg D.I fighters built under licence.
   The Royal Yugoslav Navy used at least one W.18 flying boat post-war. It was a school machine and carried the serial N9.
   The US Navy received ex-Austro-Hungarian W.18 A87 after the war along with Lohner S.3, S26, L126, R9 and Mickl A125. These machines were shipped to the US by the USS Nereus in April 1920. A later listing gives S32 instead of S3 and A126 instead of A125. The W.18 had a 230-hp Hiero engine. None of these boats were considered airworthy and they were given Bureau Nos. A-6049 to A-6054 inclusive in April 1921 for record purposes as they were not considered to be worth the expense of placing them into flying condition. No indication of a connection between the Bureau Numbers and the aircraft has been found. On 5 May 1921, Survey Report 182-21 recommended that they be stricken. This was carried out in September when they were stricken as a group. No photographs of these machines in US hands are known to exist.


Type W.18 Production
Serials Notes
A50 - A51 200-hp Hiero.
A51 - A70 230-hp Hiero. A52 was delivered in German naval hexagon camouflage.
A71 - A72 200-hp Hiero.
A73 - A79 230-hp Hiero.
A80 - A86 200-hp Hiero.
A87 230-hp Hiero.
A88 - A96 Supplied without engine.


Brandenburg W.18 Specifications
Source Typenschau Gray & Thetford SVK MN 2138 George Haddow Data Schupita Data
Dimensions in m
Span 10.70/10.30 10.7 10.700/10.300 10.7/8.92 10.7/10.3
Chord 1.80 - 1.800 - -
Length 8.15 8.15 8.150 8.64 8.15
Hull Length 7.60 - 7.600 - -
Hull Width 0.965 - 0.965 - -
Height - 3.45 3.450 3.45 -
Areas in m2
Wings 34.38 34.38 34.38 - -
Ailerons 1.90 - 1.90 - -
Elevators 1.08 - 1.08 - -
Rudder 0.57 - 0.57 - -
Weights in kg
Empty 875 875 875 812 716
Loaded 1,145 1,145 1,145 1,092 941
Performance
Speed in km/hr 160 160 - 180 -
Time to 800 m 3.9 minutes - 3.9 minutes - -
Time to 1000 m 5 minutes 5 minutes 5 minutes 5 minutes -
Time to 1500 m 8.1 minutes - 8.1 minutes - -
Time to 2000 m 11.2 minutes - 11.2 minutes 11.2 minutes 9 minutes
Time to 3000 m 23.4 minutes 23 minutes 23.4 minutes 23.4 minutes 15 minutes
Ceiling, m - - - 4,000 5,000
Range - - - 400 km -
Motor 200-hp Hiero 150-hp Benz Bz.m 150-hp Benz 230-hp Hiero 200-hp Hiero/230-hp Hiero


Type W.23

   The W.23 was a further development of the single-seat fighting flying boat. Three of the experimental Class EMGMK were ordered, MN 1647 - 1649. The machine was to be armed with one machine gun and a 2-cm Becker cannon. The boat was of conventional Brandenburg construction and resembled the other boats in the Brandenburg family with its pusher installation, swept lower wing, single-step hull, and wing floats.
   All three were built and delivered. MN 1647 was recorded at the Hage Repair Depot in November 1918. Further details are lacking. One source states that they had poor flight characteristics.(22)

(22) Leaman, P. "The Hansa-Brandenburg Seaplanes Pt.3," Cross & Cockade International, UK, 2011. Vol.42 P.97.


Brandenburg W.23 Specifications
Source Typenschau Branden. 3-View* SVK MN 1647
Dimensions in m
Span, Upper 10.70 10.700 10.700
Span, Lower 10.24 10.240 10.130
Chord, Upper 1.80 1.800
Chord, Lower 1.80 1.650
Length 9.13 9.140 9.125
Height 3.600
Hull Length 8.60 8.600
Hull Width 1.00 1.000
Areas in m2
Wings 34.70 34.7
Ailerons 2.25 2.10 2.25
Elevators 1.00 1.04 1.00
Rudder 0.50 0.45 0.50
Weights in kg
Empty 918 918 907
Loaded 1,261 1,261 1,250
Performance
Speed in km/hr 165 165
Time to 800 m 6 min. 6 min.
Time to 1000 m 7 min. 7.7 min.
Time to 1500 m 12 min. 12 min.
Time to 2000 m 18.2 min. 18.2 min.
Time to 3000 m 38.3 min. 38.3 min.
Motor 160-hp Mercedes 105-hp Mercedes 160-hp Mercedes
* 3-view dated 14.01.19

Brandenburg W.19
  
   The W.19 was a larger and more powerful two-seat naval fighter that followed the W.12. It had been found from operational experience that a machine with more endurance was required and the W.19 was designed to meet this specification. The usual three prototypes were ordered, MNs 1469 - 1471. Aircraft 1469 is reported to have crashed on its first flight, sometime in August 1917. Another source indicates that MN 1469 was used for static testing and not delivered. Research by Ron Kintner has established that MN 1469 was deleted without being allotted to any naval air station, while MNs 1470 and 1471 are recorded in the Daily Orders of the Chief of Naval Aviation. Although at least 77 of the 115 W.19 biplanes ordered are confirmed built, pictorially the W.19 remains one of the least photographed Brandenburg floatplanes that entered active service. The type was operated with the W.12 and was not reported by their opponents as a new type.
   The W.19 with a larger wing span than the W.12 featured two-bay wings. On the prototypes these had cable bracing in each bay; however, on production machines the inner bay was wireless. Of similar configuration and construction to the W.12 it was considerably larger and possessed a greater endurance and radius of action. When equipped with the more powerful 260-hp Maybach engine(54) performance did not suffer and the two types could operate effectively together, although it appears that the Brandenburg Kastas gave up their W.12 fighters and were entirely equipped with the W.19 as numbers allowed. The W.19 was reportedly easier to fly than the earlier 150-hp Brandenburg but not as manoeuvrable.
   Borkum flew large patrols of the W.19 from August to early October. On 8 October the W.19 fighters at Borkum were transferred to Norderney and they were replaced by the W.29. Details of the operations of the W.19 from other naval air stations are sketchy. Despite this the W.19 was an effective fighter and did enable the German naval aviators to keep up the pressure on their British opponents until they were replaced by the W.29. A total of 115 W.19 fighters were ordered; however, only 77 can be confirmed. It is not known if all the machines of the last batch were delivered. The Japanese expressed interest in the type and obtained MN 2690 post-war.

Operational Use of the W.19(55)

   It appears orders for the distribution of the W.19 were issued in February 1918. Aircraft were to be shipped to Zeebrugge and Borkum. The later received its first W.19 biplanes by May. The first operational use of the Borkum's W.19 fighters was on 10 May. A formation comprising two W.19 and a Friedrichshafen FF49C floatplane left on a morning patrol. W.19 MN 2208 was forced to alight at sea, the Friedrichshafen, MN 1825, also landing. The other W.19, MN 2211, returned and reported. A rescue flight was sent out but did not locate the downed aircraft. The Friedrichshafen was located and towed in but the crew of the W.19 had to sink their aircraft and were interned in the Netherlands.
   The British discovered that the Germans accompanied their mine-sweeping vessels with light vessels, and support capital shops were sometimes patrolling or even anchored in the inner Bight. Coastal Motor-Boats (CMBs) being of shallow draft and equipped with torpedoes could be carried to near the mine-field and released for a dash across to the inner part of the Bight and attack any capital targets of opportunity. It was proposed that flying boats from Yarmouth and Felixstowe would patrol off the Dutch islands to distract the attention of German seaplanes from the CMBs. A number of such operations were carried out with limited or no success. During one such operation on 1 August, a Zeppelin made a bombing attack on the naval forces. As it appeared that the Zeppelin commanders were losing their sense of caution it was determined to carry a fighter on the next excursion.
   On the evening of 10 August the Harwich Force set out again with the CMBs and a Sopwith 2F.1 Camel on a towed lighter. A few minutes after the CMBs started their run the Force was sighted by some German seaplanes that kept the Force under reconnaissance. These were probably those from Kasta 5 that was making the first patrol of the day. At 7.10am the Yarmouth flying boats arrived and were directed to the position of the German seaplanes. The weather conditions allowed the surface ships to easily view the German machines but they were not visible from the flying boats that set off in the wrong direction. They returned and asked for more information and were directed to seek out the CMBs that should have been returning. No sighting of the motor-boats was made. While this was in progress the L.53 made an appearance and Lt. Stuart D Culley took off in his Sopwith 2F1 Camel N6812 and soon after the remains of the Zeppelin fell into the sea. The CMBs were now overdue and the destroyers and light cruisers were ordered to sweep in search of them. Flying boats from Yarmouth were dispatched but no sign of the missing boats was found.
   After being launched from the cruisers, the motorboats had moved towards the Dutch coast and then turned and ran along the coastline outside Dutch territorial waters. Six seaplanes were sighted but were thought to be British until they were close enough for the black crosses to be made out. These were Brandenburg W.29 biplanes of Kasta 5. The CMBs closed up to concentrate the fire of their Lewis guns and were soon in a running duel with the German seaplanes that bombed and strafed the motor-boats. After about half an hour the leader decided to return to the Harwich Force, and then four fast fighting seaplanes with twin forward-firing guns arrived. Actually Brandenburg W.19 biplanes of Kasta 1 and Norderney W.12 and W.29 aircraft arrived, and continued the attack. Keeping the sun at their backs the Germans dived on the motorboats, "defined in clear detail, and the fire from the seaplanes, opened with fair accuracy at long range, was maintained without break and with increasing sureness of aim as they neared the luckless crews." The fight took place four miles off the Dutch coast. One boat managed to reach the shore. Another caught fire but managed to get within half a mile of the shore before it blew up. Two were sunk by their crews when they ran out of ammunition and fuel. They were picked up after three hours in the water by a Dutch torpedo boat. Two others drifted into Dutch waters and were salvaged by the Dutch. All the crew survived to be interned but four officers and two men had been wounded.
   Three Borkum W.19 crews were credited with a motor-boat each. Two Norderney W.12 crews and one W.29 crew also received credit for one motorboat each. One Norderney W.29 had been shot down in the action and its crew killed. Also a Norderney W.12 had to alight with a bullet in the radiator and had to be towed in by a torpedo boat. Activity continued all day with all six Borkum Kastas flying a mission and Kasta 5 flying two.
   On 30 May 1918, two flying boats from Great Yarmouth were making a reconnaissance over the Borkum area when Curtiss H.12 convert 8660 was forced to alight with engine trouble. The accompanying flying boat was notified by Aldis lamp that the trouble was repairable, and it circled the downed boat until after about 50 minutes two German fighting seaplanes appeared and a combat ensued. The two forward guns on the flying boat jammed after a few rounds; however, the German seaplanes turned and flew off in the direction of Borkum with the evident intent of bring back reinforcements. The British boat pursued the Germans until he realized he was too far from his damaged comrade and he turned back but could not locate the Curtiss boat. Finding nothing after a long and careful search, he flew home at 4.45pm with only about twenty minutes fuel left. At 6pm Capt. R. Leckie took another boat out to search for the missing boat. Not long after he departed a pigeon message arrived stating that 8660 was on the water and being attacked by three "Huns."
   H.12 8660's engine had been fixed and the boat had left the water and continued on its patrol. After three-quarters of an hour the machine was again forced to alight with engine trouble. In the meantime the Borkum station had sent out four seaplanes, three Brandenburg W.19 fighters and an accompanying Friedrichshafen FF49C MN 1830. This was Kasta 1 that had been equipped with the W.19 from 25 May, flying its last patrol in the W.12 on 3 May. The Germans found 8660 on the water and immediately attacked, circling the boat and letting their observers fire on the machine on the water. MN 2213 had to break off the attack due to engine trouble. Two diving attacks were made when the attackers noted that three men had left the boat and were swimming away from it and so they ceased their attack and landed to pick up the swimmers. Two were taken captive and the other drowned. The Friedrichshafen taxied up to the boat and the observer went onboard to find the mechanic wounded in the head by splinters and the pilot, Capt. Charles L. Young, DFC, dead at the controls. As the flying boat could not be towed back to Borkum the boat was set on fire and the Germans left with their three POWs.

W.19 Engines

   There were numerous engine, armament, and equipment variations within W.19 production. For example, airplanes through the first three production batches were generally scheduled to receive the 240-hp Maybach Mb.IVa engine, but when struck off charge some individual airplanes had the high-compression 260-hp Maybach Mb.IVa engine. It is not known if the more powerful engine was installed during production or retrofitted after delivery. The fourth production series was scheduled to have the 260-hp Maybach Mb.IVa. On 12 August 1918 this series was allotted between Kofl F (North Sea) and Kofl Marinekorps (Flanders).
Confusingly, both the Maybach 240-hp and 260-hp engines apparently shared the designation Mb.IVa. The engine rated at 240-hp had cast iron pistons, produced a maximum of 245-hp, and weighed 400 kg. The engine rated at 260-hp had aluminum pistons, produced a maximum of 300-hp, and weighed 390 kg. Both engines had six cylinders of 165mm bore and 180mm stroke and developed their rated power at 1,400 RPM. From these similarities it appears they were essentially the same engine with different pistons, power ratings, and compression ratios, but with little or nothing to distinguish between them visually. The reduced reciprocating mass of aluminum pistons allows the engine to rev more easily, and the improved thermal conductivity enables a higher compression ratio before knocking/pinging.

(54) The prototypes, and many early machines, were powered by the 240-hp Maybach.
(55) This section is based on the research of R. Kintner. See "The Brandenburg W.19 - Operational History", Over the Front Journal, Vol.26, No.4,2011.


Brandenburg W.19 Production
Marine Numbers Class Engine Delivered Notes
1469 - 1471 C2MG Mb.IVa The engine used in 1469 is unknown, the machine was destroyed on its first flight August 1917. The other two had the 240-hp Maybach.
2207 - 2216 C3MG Mb.IVa Apr. - May 1918 2215 cancelled 2 Apr. 18, due to faulty workmanship
2237 CK Mb.IVa Apr. 1918 20mm Becker Kannon test installation
2238 - 2257 C3MG Mb.IVa Jan. - June 1918
2259 - 2278 C3MG Mb.IVa Feb. - June 1918 2267 accepted in second half of June 1918 had a 260-hp Maybach. 2278 MGMK. Some aircraft CHFT2MG
2537 C3MG Mb.IVa May 1918 Replacement for 2215
2544 - 2563 CK Mb.IVa Also 1MG1MK. Most found at Warnemunde by Allied Armistice Naval Commission (See Appendix in Vol.3).
2683 - 2722 C3MG Mb.IVa 2687 &. 2688 to Italy post-war


Brandenburg W.19 Specifications
Source Typenschau Gray & Thetford Brandenburg 3-view SVK MN 1470 SVK MN 2208
Dimensions in m
Span 13.80/13.80 13.80 13.800/13.800 13.800/13.800 13.800/13.800
Chord 8.470 9.450 8.690 9.600 9.600
Length 3.230 3.550 3.300 3.300 3.300
Height 1.800 1.800 1.800 1.800 1.800
Areas in m2
Wings 57.80 57.8 - 50.46* 57.80
Ailerons 5.00 - 2.28 5.00 -
Elevators 2.27 - 1.62 2.25 -
Rudder 1.25 - 0.75 1.25 -
Empty Wt, kg 857 977 959 997 1,056
Loaded Wt, kg 1,314 1,434 1,230 1,454 1,550
Performance
Speed in km/h 151 150.5 - - 150.5
Time to 800 m 6.7 minutes - - - 6.7 minutes
Time to 1000 m 8.4 minutes 6.4 minutes 8.4 minutes 6.7 minutes 8.4 minutes
Time to 1500 m 13.8 minutes - 13.8 minutes 10.2 minutes 13.8 minutes
Time to 2000 m 18.9 minutes 18.9 minutes 18.9 minutes 14.2 minutes 18.9 minutes
Time to 3000 m 23 minutes 23.0 minutes 28.7 minutes 25.1 minutes 23 minutes
Endurance - 5 hours (approx) - - -
Engine 260-hp Maybach 260-hp Maybach Mb.IV 260-hp Maybach 240-hp Maybach -
* This discrepancy cannot be explained as the span and chord are the same for both Atlas entries.

Type W.20 and Submarine-Borne Aeroplanes

   In the last half of 1917 and the first half of 1918, three Brandenburg W.20 flying boats were delivered to the German Navy. The W.20 was a small reconnaissance flying boat designed as Class Bu, to be carried by a submarine. The history of the decision to build such an aircraft has not been uncovered to date, but aircraft had liaisoned with submarines and the submarine-borne aircraft was a logical way to develop a means to widen the range of vision of a U-boat on patrol. The success of the raider SMS Wolf was due in no small part to the use of the Friedrichshafen 33E floatplane that had been carried by that ship. While the Wolf returned to Germany on 24 February 1918, and the development of a submarine-borne aircraft was already proceeding, it seems logical to infer that the use of an aircraft by a ship or submarine was not lost to the German Navy, indeed it would have reinforced the desire to produce a successful machine to be capable of being used with the large U-Boat cruisers being developed.
   Brandenburg received an order on 30 April 1917, for three floatplanes (MNs 1478 - 1483) and three flying boats (MNs 1551 - 1553) to meet the requirement for a submarine-borne aircraft. The floatplanes were cancelled on 9 November. The flying boat was given the designation W.20 and was a single-seat reconnaissance flying boat designed to be dismantled to fit into a 20 foot x 6 foot space in order to enable it to be carried by a submarine. It took 2 3/4 minutes to reassemble the aircraft and 1 3/4 minutes to dismantle. Part of the specification was that no tool other than a hammer should be used to assemble/disassemble the aircraft. This was to prevent delays that could prove disastrous to a submarine if tools were mislaid. A full-sized mockup was built to check that the proposed machine would fit into the cylinder that would be carried outside the submarine's pressure hull.
   It appears from the testimony of Ernst Rothenburg, who had come to Brandenburg from Dornier as chief engineer in charge of metal construction, that the W.20 series were used to develop the concept and once the ideal machine was derived, an all-metal aircraft would be built for active service.
   Apart from its small size the W.20 was a conventional Brandenburg construction aircraft with wooden hull and fabric-covered wooden wings. A Brandenburg three-view drawing of 22 June 1917, shows the W.20 with the upper wing of lesser span than the lower wing and interplane struts. On the first boat, MN 1551, the upper wing was supported by the centre-section struts with two long struts from the hull to about one third span. The upper wing was of greater span than the lower wing. The lower wing would have been of cantilever construction similar to that of the W.17. This arrangement proved insufficient in practice. MN 1551 suffered severe damage in October 1917, possibly during trials. The second version of the W.20 had the upper and lower wing increased in span and interplane struts for a greater margin of safety. Two of these flying boats were built, MNs 1552 - 1553, and 1551 was modified with interplane struts to a similar configuration. MN 1552 was delivered to the SVK in March 1918. Tested during the period 1 to 15 April, 1552 was flown several times but could not perform the trials required as modifications requested had not been carried out by the factory. Nevertheless, the W.20 was accepted by the Navy and the aircraft was modified by Brandenburg and the repaired Marine Numbers 1551 and 1553 were shipped to Warnemunde.(9)
   It appears that nothing further was done with these aircraft. The three W.20 boats were stored at Warnemunde when inspected by the Allied Naval Armistice Commission on 7 December 1918. The machines were dismissed as "an abandoned experimental design". Only the US appears to have acknowledged the advanced concept that the Germans were working on with regards to submarine borne aircraft.(10)
   Heinkel states that the W.20 was very important to himself as it enabled him to re-enter the aviation industry and eventually to set up his own company.
   Brandenburg received a contract for three all-metal monoplanes in June 1918, (MNs 2590 - 2592). Ernst Rothenburg was actively working on these aircraft that were apparently built and tested; however he does not describe whether they were flying boats or floatplanes, nor is their designation known. Work stopped in November 1918. There were two orders for monoplanes for submarine service that fit Rothenburg's recollections:
Orders for Monoplanes for Submarine Service
Marine No. Class Engine Notes
2590 - 2592 Bu Ur.II Work stopped November 1918
2790 - 2791 Bu Ur.II Work stopped November 1918

(9) The only known photograph showing 1551 after modification appeared in the German magazine Flugzeug, No.6,1991, P.67.This shows the wing cellule was modified to match that of 1552, confirming the Atlas drawings relating to the three machines, MNs 1551 - 1553.
(10) The British had sent out Sopwith Schneider floatplanes on the deck of the submarine E.22 in April and May 1916. They were launched and flew back to Felixstowe. The idea was not pursued owing to the difficulty of hoisting the aircraft when the submarine needed to submerge.


Brandenburg W.20 Specifications
Source Typenschau Gray & Thetford MN 1551 Gray & Thetford MN 1552 - 1553 SVK MN 1552 (1551 -1553)
Span, m 6.80/6A0 5.8 6.8 6.800/6.400
Chord, Upper, m 1.19 - - 1.190
Chord, Lower, m 1.51 - - 1.510
Length, m 5.93 5.91 5.925 5.925
Height, m - - - 2.900
Hull Length, m 5.45 - - 5.450
Hull Breadth, m 0.80 - - 0.800
Areas in m2
Wings 15.82 14.95 15.82 15.82
Ailerons 1.25 - - 1.25
Elevators 0.64 - - 0.64
Rudder 0.375 - - 0.375
Weights in kg
Empty 395 - 396 395
Loaded 567 - 568 567
Performance
Speed in km/hr 117 - - -
Time to 800 m 11.4 minutes - - 11.4 minutes
Time to 1000 m 14.9 minutes - 14.9 minutes 14.8 minutes
Endurance - - 1 1/4 hour -
Motor 80-hp Oberursel 80-hp Oberursel U.O 80-hp Oberursel U.O 80-hp Oberursel

Type W.26

   The W.26 was a long-range reconnaissance seaplane in the CMGHFT category designed for an endurance of eight hours. This machine showed Friedrichshafen influences. This biplane was one of the first assignments that Hanns Klemm had with Brandenburg.(34) A large two-bay biplane, it could carry transmitting and receiving wireless apparatus. The state of the naval air war meant that it was soon converted to a C2MGHFT machine. The pilot was equipped with a synchronised Maxim 08/15 machine gun while the observer had a ring-mounted Parabellum. The upper wing was constructed in three pieces. The outer panels were swept back. The now standard Brandenburg float strut arrangement was used, leaving the inner bay devoid of cable bracing. It could also carry small bombs. The W.26 was delayed as Klemm was placed in charge of developing the revolutionary W.29 monoplane, the former project being shelved in the interim.
   The usual three prototypes were ordered, receiving MNs 1739-1741. No further development took place. One source states that they were used for medium-range reconnaissance in the North Sea. The three prototypes were discovered at the Warnemunde Testing Station by the Allies on 14 December 1918.

   (34) Hanns Klemm had gone to school with Heinkel. A civil engineer, he served in the Army on the outbreak of war. Wounded, he was discharged and went to work for Dornier in April 1917 as a specialist in metal construction and load calculation. He worked on the Dornier metal aircraft before being lured away by Heinkel


Brandenburg W.26 Specifications
Source Typenschau Gray & Thetford Branden. 3-View
Dimensions in m
Span, Upper m 18.80 18.8 18.800
Span, Lower m 18.80 - 18.800
Chord, m 2.450*
Length, m 12.79 13.015 -
Wing Area, m2 86.30 86.3 -
Empty Wt., kg 1,675 1,675 1,675
Loaded Wt., kg 2,490 2,490 2,490
Performance
Speed in km/hr 135 135 Ca. 135
Endurance - 8 hours -
Motor 260/275-hp Mercedes 260-hp Mercedes D.IVa 275-hp Mercedes
* Both upper and lower wings

Type W.27

   The W.27 was a 1917 development of the W.12 two-seat fighting floatplane. The machine was powered by the 195-hp Benz Bz IIIb Vee-eight engine. The fuselage was virtually the same as that of the W.12 but the wings were different and featured "I" interplane struts. The Brandenburg three-view drawing of the Seekampf-Flugzeug-Type WXXVII shows a neatly cowled engine with a spinner to the propeller similar to the W.32. Performance was not improved enough to warrant production. All three were constructed but only photographs of MN 2202 appear to have survived. The type ended its days as a training machine. Unlike the Allies, Germany had problems with developing a Vee-eight engine during the war years and the failure of the W.27 may have been attributed to its engine.

Brandenburg W.27 Specifications
Source Typenschau Gray & Thetford Brand. 3-View
Dimensions in m
Span, Upper 11.20 11.2 11.200
Span, Lower 10.50 - 10.500
Length 8.32 9.23 8.320
Height - 3.057 -
Wing Area, m2 36.6 36.6 36.06
Empty Wt., kg 1,109 1,109 1,109
Loaded Wt., kg 1,619 1,619 1,619
Engine 195-hp Benz 195-hp Benz Bz.inb 200-hp Benz V- form

Brandenburg W.27 Production
Marine Numbers Class Engine Notes
2201 - 2203 C3MG Benz Bz.IIIbo One machine had a Benz Bz.IIIbm


Brandenburg W.32
  
   The W.32 was an early 1918 development of the W.27 with the standard straight-six 160-hp Mercedes engine, the Typenschau stating that the machine was a conversion of the W.27. It would seem from the allocation of the Marine Numbers that the W.32 was Brandenburg's attempt to salvage the effort that went into the development of the W.27. Five W.32 biplanes were ordered but only the first three were built, the last two being cancelled in April 1918 so that Brandenburg could concentrate on the superior W.29 monoplane. MNs 2282 - 2286 were allotted to these Class C3MG machines. They were delivered to Kiel-Holtenau in early 1918.

Brandenburg W.32 Specifications
Source Typenschau Gray & Thetford SVK MN 2282
Dimensions in m
Span, Upper 11.20 11.2 11.200
Span, Lower 10.50 - 10.500
Stagger - - 1.300
Length 8.32 9.23 9.500
Height - 3.25 3.250
Wing Area, m2 36.06 36.06 -
Empty Wt., kg 1,063 1,063 1,063
Loaded Wt., kg 1,544 1,544 1,544
Performance
Time to 800 m 8.9 min. - 8.9 min.
Time to 1000 m 11.6 min. 11.6 min. 11.6 min.
Time to 1500 m 19.8 min. - 19.8 min.
Engine 160-hp Mercedes 160-hp Mercedes D.III 160-hp Mercedes

Brandenburg W.32 Production
Marine Numbers Class Engine Notes
2282 - 2286 C3MG Mercedes D.III Delivered early 1918.

The Van Berkel WA(49)

   Neutral nations in World War I that bordered the warring states had to upgrade their military in order to defend their neutrality. The Netherlands was particularly sited that aircraft of the combatants often overflew its territory, and damaged combat aircraft would head into the Netherlands rather than be captured, and this does not include those that were lost through navigation error, landed and were interned. As a result the Netherlands utilised these aircraft where possible. Landplanes, the majority of internees, were used by the Luchtvaartafdeling (LVA) while the Navy's air arm, the Matineluchtvaartdienst (MLD) received only 17 aircraft that were considered useful enough to warrant serial numbers from this source. Of these 11 were purchased from their former owners.
   On 31 October 1917, W.12 MN 1185 (160-hp Benz No. 26849) with crew of Flugobermaat Huthmacher and Ltn.z.S Zapp left Zeebrugge at 07.00. They became lost and ran out of fuel. They alighted on a flooded meadow that had looked like a lake from the air with hardly any damage. The crew then burned their aircraft. Zapp was interned but Huthmacher managed to evade his guards and escape back across the border. The remains were salvaged by the LVA and the motor was acquired by the MLD who most likely used it for spares.
   W.12 MN 1398 (160-hp Benz No. 26851) was acquired on 6 December. The crew of Oblt.d.Res F. Hopken and Flugmaat J. Johannsen were returning from a reconnaissance patrol to the UK when they were forced down with engine trouble. The floatplane was badly damaged and the crew clung to the floats until they managed to attract the attention of the gas transport vessel Vlissingen by firing a flare. The Vlissingen transported gas to the lightship Noordhinder. The machine was picked up some 35 km west of Westkapelle after some 22 hours adrift. The floatplane was recovered, the Vlissingen having a relief crew aboard, but only the engine was salvageable and purchased. The crew was released as shipwrecked mariners.
   Again, on 16 April 1918, W.12 MN 2035 (150-hp Benz No. 27087), with crew of Flugzeugmeister Hartmuth Frosch (or Trosch) and Flugmechanikermatt Antonie Hansen, was lost in fog and ended up on a beach at Scheveningen and was burned by the crew. The nearby Coast Guard station had not seen the machine due to the fog and arrived too late to save it from being destroyed. The Benz motor was purchased for f4,000.
   On 22 April 1918, W.12 MN 2098 (160-hp Mercedes No. 34158), alighted south of Rottum Island due to the crew of Deckoffizier Alfred Walter and Flugobermaat Leonard Wuggazer, losing their way in fog and then suffering engine failure. The Coast Guard informed the MLD base at De Mok of the alighting and a team was sent to salvage the aircraft and bring it back to De Mok. The W.12 was on a sandbank and in full airworthy condition, so OMSD3 H.J. Takens decided to leave the aircraft intact and tow it to De Mok. This was against standing instructions that stated that interned aircraft were to be dismantled; however, Takens had no facilities to dismantle the machine. Fortuitously a sailing vessel came by and Takens commandeered this, the seaplane being hoisted aboard the vessel. The machine gun was removed and the German insignia covered up as much as possible.
   Though Takens was praised for his initiative, he also had it pointed out to him that his actions may have had serious international consequences. The open transportation of a seaplane of one of the belligerent powers could have endangered Dutch neutrality. The machine was test flown by LTZ1 D. Vreede, the commanding officer of the MLD, who was impressed with the Brandenburg and as the acquisition of an up-to-date fighter seaplane was too good an opportunity for the MLD to miss, the incident was hushed up.
   The machine was purchased from the German Navy for f25,000, and taken into the MLD with the serial W-1. This became the pattern aircraft for the construction of the Van Berkel WA.
   A further W.12 identified as MN 2200 crashed near Terschelling on 2 October 1918.
   The performance and seaworthiness of the Brandenburg led to a licence being obtained for its construction in the Netherlands.(50) The Trompenburg aircraft factory was fully committed to the production of Spijker trainers, and a new manufacturing concern was necessary in order to undertake the production of the W.12. W.A. van Berkel was the successful owner of the Van Berkel Patents firm(51) and was prepared to undertake the risk of starting an aircraft manufacturing plant. Late in 1918 the factory was established at Keileweg 9, Rotterdam. The company was given a contract for 35 Brandenburg floatplanes on 15 November 1918. The contract signed by the Munitions Office and the Company was for the production of slicing machines according to Van Berkel's Patent and other tools. Why the seaplanes had to be concealed has not been revealed. They were to be equipped with the 200-hp Hispano-Suiza engine, that Van Berkel was also to manufacture under licence and be completely airworthy. The machine had to have provision for mounting two machine guns, one for the observer and a synchronised one for the pilot.
   Article 10 stated that the machine should be able to perform the same requirements of speed, climb, etc., as the seaplane V-3, when both were in the fully loaded condition. The W.12 serial W.1 had crashed and so could no longer be used for comparison purposes, therefore the Friedrichshafen FF33L, ex-MN 1581, that had been interned on 24 September 1917, and given the MLD serial V-3, was to be used instead.
   The production of the engines did not proceed well. The processes involved proved to be fraught with problems. The castings for the engines proved highly porous and were rejected. The program was terminated.
   The W.12 produced by van Berkel was named the WA after Mr. van Berkel. After a slow start things progressed better when a number of German workmen from Friedrichshafen were engaged. Takens was placed as supervisor for the Navy. The debacle of the Hispano-Suiza engines meant that another source of engines had to be found, and at van Berkel's request Takens went to Germany to obtain suitable engines. With the help of a Mr. Bruno Jablonsky, one hundred second-hand Mercedes D.IIIau engines were obtained at Tempelhof. Sixty were for the Navy with the others going to the LVA. Takens had also obtained a complete test rig from Germany. Apparently Fokker had offered BMW engines but the Mercedes were preferred as they had a better altitude performance. This comment is interesting in the light of future events. The total price including engines and propellers was 35,050 Dutch guilders.
   Due to the turmoil in Germany the engines could not be tested there and when the first engine was given a test run in the Netherlands, its output was less than the rated 180-hp. It appeared that the "duramen Hollander" had been sold a bunch of "ill fed horses." However Takens solved the problem by modifying the exhaust collector and the engines performed above their rated horsepower. With the engine problem solved and Mr. Carl Lesch engaged as test pilot, the program got under way in mid-1919.
   The first WA was exhibited at the ELTA exhibition in Amsterdam. It was to be used for sand loading testing. The second machine was sent in a dismantled state to the MLD base at Schellingwoude, where it was tested on 6 September 1919, by LTZ1 H. Nieuwenhuis with Takens in the rear cockpit, becoming the first WA to fly. The performance was so good that they decided to fly to Rotterdam that afternoon. Van Berkel, always good for publicity, had notified the populous of the intending flight by placing bulletins in cafes and tobacco shops. Nieuwenhuis made circuits over the ELTA exhibition before flying to Rotterdam. By the time they landed a big crowd had gathered. After refreshing themselves from Van Berkel's Patent's motorboat, the pair took off and returned to Amsterdam.
   W-1 and W-2 were accepted in October and in November were crated and sent to the Netherlands East Indies (NEI). The NEI received W-1 to W-12, W-12a, and W-14 to W-20. Although 13 was used in serial designations, for the WA it was not used and 12a substituted instead. The NEI also had W-21c that was built at the MLD station Morokrembangan, Surabaya, from the remains of W-11 and W-19. The wooden floats were not up to the conditions suffered in the NEI and aluminium floats built by the Dornier works at Friedrichshafen replaced them.
   The NEI was a vast archipelago comprising many islands spread over many hundreds of square kilometers of sea. These islands with their sheltered bays and inlets were ideal for the operation of seaplanes as the Japanese would demonstrate in World War II. The MLD had tried previously in 1918 to employ seaplanes by shipping a Friedrichshafen and Rumpler seaplane to the area, but both were wrecked and written off in 1920.
   Eight destroyers were modified to carry a WA on the stern. All new ships had to be able to carry an aircraft. This greatly extended the range in which the WA floatplanes could operate. The machines were used for hydrographic duties, spotting reefs, medical services by flying needed medical supplies into isolated areas, showing the flag, and giving local leaders flights to increase their local prestige. All this was in addition to their normal naval duties of spotting for the fleet. The only disadvantage of the WA in the NEI was its short range. The floatplanes were based at the old Army seaplane station at Tandjong Priok, and later Surabaya. Due to the fact that the aircraft could not make the trip between the two stations in one flight, an auxiliary base was established at Semarang.
   In the Netherlands serials W-51 to W-70 were allocated to WA floatplanes. However, it is thought that W-66 to W-70 were actually built by the MLD. The repair shops at De Kooy would often build complete aircraft from the remains of wrecked aircraft and spares. For example the wreck of W-63 was transported to De Kooy by barge; that same day a brand-new W-63 was transported back from De Kooy.
   In October 1924 a steel-tube fuselage was built for the WA at De Kooy, and proved successful. Thereafter all WA biplanes were given a fabric-covered steel fuselage when in for repair. W-67 was written off in July 1930, the last of the wooden fuselage WA biplanes. The type continued to serve until 1934 when they were finally retired. Only three fatal crashes concerned the WA; however, in all cases both crewmen were killed.
- W-57 on 28 September 1925, near Den Helder.
- W-16 on 2 June 1927, in the Java Sea.
- W-54 on 2 September 1930, at the Loosdrecht Lakes.
   As in the NEI ships were adapted to carry the WA biplanes, in the Netherlands the ironclads HMS Hertog Hendrick and HMS Jacob van Heemskerk were modified to carry aircraft.
   The WA could mount a 7.7 mm Vickers machine gun on the gun ring. This was never carried on fleet exercises. When not in use the gun could be lowered into a slot in the fuselage that was covered by an aluminium panel. Despite the contract calling for a synchronised gun for the pilot this was never fitted to the WA.
   During its long service the WA had many modifications. The metal fuselage with fabric covering and metal floats has been mentioned above. From 1927 dural floats were used in the Netherlands.
   From 1925 the Mercedes engines were replaced during overhaul with the 185-hp BMW IIIa six-cylinder inline engine. The wing mounted radiator was replaced by a car type radiator mounted in the nose.
   Both in the Netherlands and the NEI the tailplane had a double set of supporting struts. No reason is given for their fitting as the original German machines did not require any additional bracing.
   A larger rudder was introduced to help with taxying. Following the introduction of the more powerful BMW engine the elevator balance and tailplane area were increased in late 1926 to overcome instability in flight due to the new engine.
   The Netherlands Navy requested a two-seat long-range monoplane similar to the Brandenburg W.29. Baumhauer designed a monoplane for Van Berkel that was a completely new design of larger proportions and powered by a Rolls Royce Eagle VIII engine. Six of these WB monoplanes were built and are often referred to as Brandenburgs, but apart from some superficial similarities, the WB was a completely new design. The WB was the last aircraft built by Van Berkel.

(49) This section has been written in the main from the researches of Fritz Gerdessen.
(50) This section has been written in the main from material supplied by the Netherlands Bureau Maritieme Historie, translated by Fritz Gerdessen.
(51) Wilhelmus Adrianos Van Berkel successfully patented, manufactured and sold meat slicing and weighing machines. He was internationally famous and rich by the time of the war. His firm made rifles and ammunition for the Dutch Army after the outbreak of the war. He always produced to specification and had a good reputation with the military.


Van Berkel Patents WA Specifications
Source Bureau Maritieme Historie MLD Type WA 3-View
Dimensions in m
Span, Upper 11.17 11.270
Span, Lower 9.60(52) 9.475
Length - 9.475
Height 3.35 4.250 (incl. rad.)
Wing Area, m2 36.20(53) -
Empty Wt., kg 997 -
Mil. Load, kg 230 -
Loaded Wt., kg 1,454 -
Performance
Max. Speed 135 km/h -
Cruise Speed 120 km/h 6 min.
Time to 1000 m 7 min. 8 min.
Time to 1525 m - 13 min.
Time to 2000 m 18.9 min. 20 min.
Time to 3000 m - 38 min.
Service Ceiling 4,500 m -
Range at Cruise 580 km -
Engine Mercedes D.IIIau -
(52) According to "Van Berkel seaplanes" by N. Geldhof, (Air Britain Digest, Summer 1995, P.43), the span of the lower wing was 10.49 m. All other dimensions quoted are the same as those quoted in the Bureau Maritieme Historie paper.
(53) An article in de Modelbouwer gives an area of 35 m2.