J.Herris German Seaplanes of WWI (A Centennial Perspective on Great War Airplanes 15)

Oertz W5
  
  The Oertz W5 design was similar to the earlier Oertz flying boats but it was larger and more powerful. It featured a three-bay wing and was powered by the 240 hp Maybach Mb.IV. Five boats, Marine Numbers 276-280, were ordered in August 1914, making the W5 the Oertz type constructed in the largest numbers. Production was extremely slow; the first was not delivered until May 1916 and the last was not delivered until February 1918.

Oertz W5 Specifications
Engine: 240 hp Maybach Mb.IV
Wing: Span 18.0 m
Area 77.0 m2
General: Length 10.7 m
Empty Weight 1,580 kg
Loaded Weight 2,250 kg
Maximum Speed: 120 km/h


Oertz W7

  Two examples of the Oertz W7, Marine Numbers 474-475, were ordered in April 1915; they were delivered in May and June 1916. The W7 boats were powered by a 150 hp Maybach Mb.Ill and were similar in configuration to the W5 but were smaller, two-bay boats.

M.Dusing German Aviation Industry in WWI. Volume 2 (A Centennial Perspective on Great War Airplanes 85)

Max Oertz, Jachtwerft, Neuhof-Reiherstieg (Hamburg)
  
Aircraft Development:

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  The Oertz W.5 flying boat specially designed for a the 240 hp Maybach engine. This machine was presented to the Navy by Messrs. Krupp von Bohlen and Halbach. All previous experience was taken advantage of in the design of this boat, and especially was the step question solved successfully.
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Журнал Flight

Flight, October 9, 1919.

THE OERTZ FLYING BOATS

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   "It was not long before a demand arose for larger and more powerful boats, and the Oertz Works received an order for a series of flying boats, which were to be fitted with 260 h.p. Argus engines. Delivery of these engines was much delayed, and when they were available they proved to have exceeded the estimated weight to such an extent that it was quite out of the question to fit them in the Oertz boats. It was, therefore, decided to fit, instead, the 240 h.p. Maybach airship motors, which were at that time quite new. This was done, and in the autumn of 1915 the first of these boats could be delivered. In spite of the fact that the boats were really too large for the engines' power, which was lower than that for which they were designed, and that the engines were heavier than had been the estimated weight of the Argus engines, the boats were able to pass their acceptance tests. One of these boats is shown in Fig. 5.
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