| Sh.III | |
|---|---|
 | |
| A Siemens-Halske Sh.III at the Museo Storico dei Motori e dei Meccanismi in, Palermo, Italy | |
| Type | Counter Rotary engine |
| National origin | Germany |
| Manufacturer | Siemens-Halske |
| Major applications | Siemens-Schuckert D.III and D.IV |
| Number built | approx 1,200 |
| Developed from | Siemens-Halske Sh.1 |
The Siemens-Halske Sh.III was an 11-cylinder, air-cooled counter rotary engine developed in Germany during World War I. [1] The engine was a development of the earlier 9-cylinder Siemens-Halske Sh.I. [2]
The Siemens-Halske Sh.III was an 11-cylinder counter rotary engine. [1] The Sh.III's propeller and cylinders were connected, these rotated anti-clockwise when viewed from the front of the aircraft (clockwise when viewed from the pilot's seat) while the crankshaft rotated clockwise. [1]
The crankshaft was driven at 900 rpm via a set of bevel gears, located at the back of the engine, with a 2:1 ratio. The cylinders and propeller would have rotated at a speed of 1800 rpm anti-clockwise had the crankshaft been fixed. With the crankshaft rotating at 900 rpm clockwise the net propeller rotational speed was reduced to 900 rpm. [1]
The counter rotary design allowed the engine to achieve the benefits of a high-power density from a high rotational speed while the propeller operated at a slower speed optimised for its design. By the end of WW1, operating the propeller at a slower speed than the engine had become normal practice for inline and V block engines but had proved difficult to accomplish on rotary engines. [1]
Additional benefits of the counter rotary design were lower aerodynamic losses [1] and reduced gyroscopic forces as the net cylinder rotational speed was reduced when compared to a conventional rotary of similar power output. [1] [2]
Unlike most rotary engines the Sh.III had a throttle which could reduce engine speed to 350 rpm. [2]
The Sh.III was initially designed with a power output of 160 hp. A later variant, the Sh.IIIa, had a power output of 200 hp with some examples developing as much as 240 hp. [2]
In operation the Sh.III suffered from poor reliability. The engine tended to overheat as the relatively slow rotation of the cylinders limited cooling air flow. Additionally, seizures of the engine were caused by poor lubrication as the Germans did not have access to castor oil [1] [2] which was one of the few oils that could retain its properties after being mixed with gasoline. [1] [3]
Data from Airplane Engine Encyclopedia [4]
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Siemens-Schuckert was a German electrical engineering company headquartered in Berlin, Erlangen and Nuremberg that was incorporated into the Siemens AG in 1966.
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Pfalz Flugzeugwerke was a World War I German aircraft manufacturer, located at the Speyer airfield in the Palatinate. They are best known for their series of fighters, notably the Pfalz D.III and Pfalz D.XII. The company went bankrupt after the Armistice, when the French occupation forces confiscated all of the equipment, but the factory was re-used by various other companies until re-forming in 1997. Today they are a parts manufacturer referred to as PFW.
The Mercedes D.III, or F1466 as it was known internally, was a six-cylinder SOHC valvetrain liquid-cooled inline aircraft engine built by Daimler and used on a wide variety of German aircraft during World War I. The initial versions were introduced in 1914 at 160 hp, but a series of changes improved this to 170 hp in 1917, and 180 by mid-1918. These later models were used on almost all late-war German fighters, and its only real competition, the BMW III, was available only in very limited numbers. Compared to the Allied engines it faced, the D.III was generally outdated.
The Pfalz D.VIII was a German World War I fighter aircraft.
The Fokker V.7 was a prototype German fighter triplane of World War I, an attempt to improve upon the Dr.I by using the experimental Siemens-Halske Sh.III, double acting rotary engine.. To make use of the higher power and rpm, the aircraft had a four-bladed propeller of larger diameter than the Dr.I. This required longer landing gear. The rear fuselage had to be extended to compensate for the heavier engine. Four V.7 aircraft were built. The V.7/I was in the fighter flyoff competition in January 1918. The performance of the V.7 was outstanding, but the engine was not ready for service. The Fokker V.7/I was converted to a Dr.I.
The Siemens-Schuckert D.I was a single-seat fighter built by Siemens-Schuckert Werke in 1916. It was a German copy of the French Nieuport 17 that was obsolete by the time it was available in numbers, so that it served mainly as an advanced trainer.
The Siemens-Schuckert D.III was a German single-seat fighter built by Siemens-Schuckert Werke. The D.III was a development of the earlier Siemens-Schuckert D.IIc prototype. The D.III was an (nearly) equal-span biplane powered by a 160 hp (119 kW) Siemens-Halske Sh.III bi-rotary engine. Idflieg placed an order for 20 aircraft in December 1917, followed by a second order of 30 aircraft in February 1918.
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The Siemens-Schuckert E.I was a German fighter aircraft, manufactured by Siemens-Schuckert.
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The Siemens-Schuckert DDr.I was a World War I German twin engine, push-pull configuration triplane fighter aircraft. Only one was built, crashing on its first flight.
The Pfalz D.VII was a German biplane fighter aircraft from World War I. It was not put into production.
The LFG Roland D.IX was a World War I German single seat fighter aircraft, a biplane powered by one of a new generation of powerful rotary engines. Three slightly different prototypes were built but there was no series production.
The LFG Roland D.XVI, initially designated the LFG Roland E.I, was a single-seat, single-engine, parasol wing German fighter aircraft flown close to the end of World War I. Only two were built.
The Siemens-Schuckert Dr.I was a German single seat triplane fighter aircraft first flown in 1917. Its development and that of a more powerful, uncompleted variant, was abandoned after a flight test programme.
The Siemens-Schuckert B was an unarmed German two seat reconnaissance biplane built early in World War I. A single example was delivered but soon lost.
The Pfalz Dr.II was a German triplane fighter prototype of World War I built by Pfalz Flugzeugwerke.
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