G.Haddow, P.Grosz The German Giants (Putnam)
Staaken R-plane Projects
Staaken engineers were active in investigating new rib sections, undercarriage assemblies, geodetic structures and the hundreds of constructive details that comprise an R-plane. During their stay at Gotha, VGO engineers had already begun work on an enlarged R-plane design. Philipp Simon, head of the materials testing laboratory, recalls that it was a biplane with wings of 50 metre span and 6 metre chord. He continues:
The power plants were not known to me, but we built a substantial wing section for experimental load testing. It was a rather big undertaking, as we had to simulate flight loads by sand loading to a carefully prepared profile until the final collapse. But the project, which had cost the firm a considerable sum, was never continued.
Information regarding the Staaken projects under design or construction in 1917 and 1918 is sparse, and what has come to light is the subject of much intriguing speculation.
In 1917 the military authorities began to support the development of high-performance R-planes capable of executing daylight attacks. In order to achieve this goal an increase in overall performance was mandatory. Engineers had to resort to the latest materials and construction techniques and utilize the newest aerodynamic concepts if an R-plane capable of meeting enemy fighters on equal terms was to become a reality. It was logical that the choice would fall on all-metal R-monoplanes with accessible engines buried in thick, cantilever wings, a configuration developed by Junkers and adopted by AEG and Staaken, all of whom had R-monoplanes in various stages of completion at the end of the war.
In the case of Staaken, transfer of engineers fully versed in Dornier's revolutionary metal fabrication process enabled Staaken to begin building all-metal R-planes. The most important of these engineers was Dr. Adolf Rohrbach, an associate of Dornier since 1914, who moved to Slaaken in late 1916 or early 1917 to bring his knowledge and skills to bear on the all metal R-monoplane problem.
Von Bentivegni, in his writings, has fortunately left an important clue to the configuration of one of the Staaken R-monoplane projects. It had thick semi-cantilevered wings and was powered by five tractor engines. easily accessible in the wings and nose. A machine-gun position was located behind each engine, and armour plate protected the few but large fuel tanks in the fuselage behind the pilots' seats. The speed of the projected machine was considerably greater than that of existing R-planes. While the designation of this project is unknown, it is entirely possible that this project resembled the post-war all-metal monoplane, the Staaken E.4/20, designed by Dr. Adolf Rohrbach.
Two other Staaken Army R-plane projects have been identified. The first was known as the Staaken R.VIII, of which three examples numbered R.201/16 to R.203/16 were ordered by Idflieg.
The Staaken R.VIII was to have been an all-duraluminium bomber powered either by eight 260 h.p. Mercedes D.IVa or 245 h.p. Maybach Mb.IVa engines. The second project was the Staaken R.IX 206/16, which, as far as is known, was similar in all respects to the Staaken R.VIII.
In a March 1918 status report it states:
Staaken R.VIII 201/16 and 206/16 (2000 h.p.). Because of the final decision to construct the wings completely from metal rather than wood, the design has to be reworked and work must proceed at top speed. The Zeppelin-Werke hope, still within this month, to order the duraluminium parts for the wings in order to start assembly beginning May.
The drawings for both the R.VIII and R.IX were reputed to have been completed by April 1918. In the same report we learn that various armour-plated fuel tanks, both elliptical and diamond shaped, were under construction by Staaken.
The next month we read:
For R-planes, the first cone-shaped armoured fuel tanks are completed and will be installed in a Staaken R-plane for tests. Although a final decision has not yet been made it is planned to construct the middle section of the 2000 h.p. Staaken R-plane as a fixed armoured structure.
An Idflieg document, dated 15 March 1918, rather optimistically listed the intended delivery date for the R.201 as October 1918. It has not been determined when the construction of the R.201 was begun (if at all), how far it progressed and what its design looked like, other than that it was to be an all-metal monoplane.
It is difficult to determine why such high serial numbers were assigned out of sequence, unless the reason was that the Government purposely set these numbers aside for long-range development programmes.
No information exists regarding the Staaken R.X to R.XIII. If these numbers existed at all it is believed that they were set aside for project bureau studies.
The final Staaken project was a seaplane powered by four 530 h.p. Benz Bz.VI engines and assigned Navy Number 8307. It was ordered by the Navy in February 1918. Although further details are missing, it might be speculated that this machine resembled the Staaken R.XVI (powered by Benz Bz.VI engines) on floats.
Much technical material was deliberately destroyed or hidden by the Germans in 1919 to avoid its falling into the hands of the Inter-Allied Control Commission. The secrecy which surrounded these projects and the early post-war failure of the Staaken concern, in addition to the destruction of records in World War II makes it doubtful if the full story of the Staaken projects will ever be known.
Type: Staaken R.VIII and R.IX
Manufacturer: Zeppelin-Werke G.m.b.H., Staaken, Berlin
Eight 260 h.p. Mercedes D.IVa engines
Eight 245 h.p. Maybach Mb.IVa engines
Span, 55 m. (180 ft. 5 in.)
Length, 30 m. (98 ft. 5 in.)
Height, 8•8 m. (28 ft. 10 in.)
Type: Staaken 8307
Manufacturer: Zeppelin-Werke G.m.b.H., Staaken, Berlin
Engines: Four 530 h.p. Benz Bz.VI engines