O.Thetford, P.Gray German Aircraft of the First World War (Putnam)

Sablatnig C I
   Built during 1917, the Sablatnig C I was a conventional C type two-seater of wood and fabric construction. At least two aircraft were built, Nos. 7700/17 (illustrated) and 7702/17, which served as prototypes for the subsequent N 1 type. The vee cut-outs in the trailing edge of the lower wings are usual - and unexplained. The lights built into the leading edge of the upper wing should be noted. Six 50 kg. bombs could be carried. Engine, 180 h.p. Argus As III. Span, 160 m. (52 ft. 6 in.). Length, 8.7 m. (28 ft. 6 1/2 in.). Weights: Empty, 1,050 kg. (2,310 lb.). Loaded, 1,540 kg. (3,380 lb.). Speed, 120 km.hr. (75 m.p.h.). Climb, 1,000 m. (3,280 ft.) in 9 min., 2,000 m. (6,560 ft.) in 20 min. Armament, one Parabellum machine-gun.

Sablatnig C II
   Built round the 240 h.p. Maybach engine during 1918, the Sablatnig C II remained only an experimental prototype. The wings were braced with two bays of I-struts, and the fuselage and vertical fin were ply-covered. In many respects the machine favoured the SF 7 seaplane, the inboard wing bay being braced in identical manner. Engine, 240 h.p. Maybach Mb IV. Span, 12.5 m. (41 ft. 0 1/4 in.). Length, 8.3 m. (27 ft. 2 3/4 in.). Height, 3.2 m. (10 ft. 6 in.). Weights: Empty, 1,070 kg. (2,354 lb.). Loaded, 1,600 kg. (3,520 lb.). Speed, 150 km.hr. (93.75 m.p.h.). Climb, 1,000 m. (3,280 ft.) in 4.5 min., 5,000 m. (16,400 ft.) in 30 min. Range, 525 km. (328 miles). Armament, one Parabellum and one Spandau machine-guns.

Sablatnig Experimental C Type
   These two machines were variants of the C II machine in an obvious endeavour to compare the advantages of the more normal parallel strut arrangement (above) with the I-strut system of the C II. For further comparison the X-strut cellule (below) was tried, this machine also differing in having overhung balanced elevators. Although not confirmed, dimensions were doubtless largely the same as those for the C II. Engine, 245 h.p. Maybach Mb IV.

Sablatnig N I
   Built during 1918 to the N specification (which was first devised in August 1917), calling for a single-engined two-seat night bomber, the Sablatnig N I bore more than a passing resemblance to the C I. Probably a short series was constructed, as Serial Nos. 7729/17 and 7730/17 have been noted in addition to 7745/17 (illustrated above). Engine, 220 h.p. Benz Bz IV. Span, 16.0 m. (52 ft. 6 in.). Length, 8.7 m. (28 ft. 6 1/2 in.). Height, 3.2 m. (10 ft. 6 in.). Weights: Empty, 1,190 kg. (2,618 lb.). Loaded, 1,860 kg. (4,092 lb.). Speed, 125 km.hr. (78.125 m.p.h.). Climb, 1,000 m. (3,280 ft.) in 10 min., 4,000 m. (13,120 ft.) in 59 min. Armament, one Parabellum and one Spandau machine-guns.

J.Herris Development of German Warplanes in WWI (A Centennial Perspective on Great War Airplanes 1)

N-Types: Single-Engine Night Bombers

   The Sablatnig company, a small manufacturer primarily known for its two-seat reconnaissance floatplanes used by the German Navy, also designed an N-type, the Sablatnig N.I, that was produced in small numbers, thought to be 45 aircraft, and these also served in small numbers at the Front. Neither N-type was built in large numbers because Germany had excellent twin-engine night bombers that carried heavier bomb loads and were preferred by their crews.

J.Herris Nachtflugzeug! German N-types of WWI (A Centennial Perspective on Great War Airplanes 3)

Sablatnig N.I & Related Types
  
   Sablatnig, a minor manufacturer, is best known for its series of floatplanes produced in small numbers for the German navy. Wanting to supply the German army, which bought airplanes in much greater quantity than the navy, starting in 1917 Sablatnig produced a series of prototypes for two-seat, C-type aircraft. At least five examples of the Sablatnig C.I were built, and this design was developed into the N.I.
   The Sablatnig C.I was a conventional, two-bay biplane powered by a 180 hp Argus As.III and the first prototype had a streamlined propeller spinner that was omitted from the four subsequent aircraft. The C.I had landing lights in the upper wing and thus seems to have been designed for night operations from the beginning. Moreover, the C.I could carry six 50-kg booms, the bomb load Idflieg had specified for the single-engine night bomber type, further indicating that the C.I was designed with the Idflieg night-bombing requirements in mind. Ailerons were fitted to all wings.
   Developed from the C.I, the N.I had the more powerful 220 hp Benz Bz.IV and lacked a spinner, something that was clearly unnecessary for such a slow aircraft. In addition, the wing-mounted landing lights were moved to the lower wing for better ground illumination during night landings. Like the C.I, ailerons were fitted to all wings, and the N.I also had servo tabs mounted on the top of the upper wing ailerons to reduce the aileron control forces and improve maneuverability. Despite its substantially greater power, the N.I had similar performance to the preceding C.I.


Sablatnig N.I Orders and Production

   Like most information on the N.I, orders and production details are obscure. What is known is that a batch of 50 Sablatnig C.I aircraft with 180 hp Argus As.III engines were ordered in July 1917, receiving serials C.7700/17 to C.7749/17. Technical requirements specified were: take-off and landing run 150m, a bomb load of six 50 kg PuW bombs, totallying 300 kg, and a maximum speed of at least 125 km/h. These requirements were consistent with Idflieg’s single-engine night bomber specifications, which, together with the landing lights built into the upper wing, strongly indicate the C.I was designed to those requirements. Moreover, the early AEG N.I aircraft were originally designated C.IVn; N-class serials were first assigned in September 1917, a couple of months after the Sablatnig C.I order.
   In is not known when and why it was decided to build most of the aircraft as Sablatnig N.I(Bz) with Benz engines. Perhaps the N.I needed more power for its night-bombing role, although the AEG N.I carried the same bomb load with only 150 hp The 'Bz' suffix to the type designation is consistent with license production; if Benz built the airframes, it is reasonable that Benz engines would be used.
   Known Sablatnig C.I serials include: 7700/17, 7702/17, 7703/18, and 7704/18 (the year '18' suffixes likely a painter's mistake). Known Sablatnig N.I serials include: 7705/17, 7730/17, 7734/17, 7736/17, 7743/17, and 7745/17. From this data it seems clear that the first 5 aircraft of the 50-aircraft order were completed as C.Is and the remaining 45 were completed as N.Is.

  
Continued Development

   Development of Sablatnig C-types continued with additional prototypes. First was the Sablatnig C.II; several C.II prototypes were produced that differed primarily in their inter-plane bracing. One version had two bays featuring I-struts, another version had X-struts, and the third had conventional parallel struts. All three variants had supplementary bracing struts from the upper fuselage longerons to the lower wings, eliminating the need for bracing wires on the inner bay of struts. Ailerons were fitted on all wings connected by an actuating strut. The fuselage appeared to be a semi-monocoque plywood shell similar to those commonly used by Albatros. The C.II in its various versions was more compact than the C.I with a more powerful 240-245 h.p. Maybach Mb.IVa engine. Nevertheless, speed was significantly below requirements and no production ensued.
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In Retrospect

   Like the AEG N.I, the Sablatnig N.I was assigned in ones and twos to two-seater and bombing units and labored in obscurity performing short-range, tactical night bombing. Interestingly, the Sablatnig does not appear in the Frontbest and inventory until well after front-line AEG N.I numbers peaked. Although this could indicate the Sablatnig had a protracted development, it is more likely that some factor related to production capacity drove the Sablatnig N.I production schedule.
   The Germans preferred twin-engine night bombers for their greater reliability and bomb load, therefore the N-types were never numerous. Moreover, it is difficult to rationalize production of the Sablatnig N.I when compared to the AEG N.I, which preceded it in both production and operations. Despite the significantly greater power of the Sablatnig's 220 hp Benz Bz.IV compared to the 150 hp Benz Bz.III used by the AEG, the Sablatnig N.I was slower than the AEG and apparently carried the same bomb load. While speed was not especially important in night bombing, bomb-load certainly was. And the more powerful engine used in the Sablatnig N.I used more scarce fuel to operate. Unless the Sablatnig carried more bombs, or there was some other compelling reason such as excess production capacity at Sablatnig or Benz that would otherwise have been wasted, it is difficult to understand why the Sablatnig N.I was placed in production.
   The Sablatnig C.II derived from the N.I was a mediocre design deserving of its obscurity. However, the elegant C.III was a real design break-through, although the wire wing bracing appears vulnerable to combat damage and might have been replaced with stronger struts had development continued. The C.III appeared to have good development potential but arrived too late.


Sablatnig C.I, N.I, & C.II Specifications
Sablatnig C.I Sablatnig N.I Sablatnig C.I
Engine 180 hp Argus As.III 220 hp Benz Bz.IV 240 hp Maybach Mb.IVa
Wing Span (Upper) 16.0 m (52.5 ft.) 16.0 m (52.5 ft.) 12.5 m (41.0 ft.)
Length: 8.7 m (28.5 ft.) 8.7 m (28.5 ft.) 8.3 m (27.2 ft.)
Empty Weight 1,050 kg (2,315 lb.) 1,190 kg (2,624 lb.) 1,070 kg (2,354 lb.)
Loaded Weight 1,540 kg (3,395 lb.) 1,860 kg (4,101 lb.) 1,600 kg (3,520 lb.)
Maximum Speed 120 km/h (75 mph) 125 km/h (78 mph) 150 km/h (94 mph)
Climb to 1000m 9 min. 10 min. 4.5 min.
Climb to 2000m 20 min. - -
Climb to 4000m - 59 min. -
Climb to 5000m - 30 min.
Armament 1 flexible machine gun & 300 kg bombs 1 flexible machine gun & 300 kg bombs 1 flexible machine gun
& 1 fixed machine gun