What's New .... Updated July '24
1927 Supermarine S.5 Seaplane
1:8 Scale Model Under Construction
The Supermarine S.5 won the international Schneider Trophy race in 1927. It was the first of three consecutive wins by British seaplanes that permanently secured the trophy for Britain.
The Chief Designer for Supermarine was a young R. J. Mitchell. He later went on to greater fame as the designer of the Supermarine Spitfire.
The model is scratch built using 3D printed parts and balsa wood.
Although the Napier Lion engine in the S.5 model is similar to the Lion engine in my Napier-Railton model, the differences are such that the engine had to be completely redrawn. Notably, the crankcase, front engine housing and cylinders are quite different. The camshaft covers were also different and designed on the S.5 to be part of the body profile.
A separate, stand-alone, cut-away, VIIB Lion engine, is also being built It will stand alongside the seaplane model. It will be fully detailed including cylinder heads, camshafts and valves, plus a crankshaft, conrods and pistons. Portions of the model will be left off, or cut out, so the details can be seen.
The fuselage and pontoon frames are largely complete. The front fuselage sections was 3D printed which ensured that the engine would fit properly. Mitchell designed the fuselage to wrap around the engine to minimize the frontal area and reduce drag.
The wing frames are also done, but not shown here. You can see that the rear fuselage section is out of alignment. It will be rebuilt.
Below are photos of the completed engine that will be mounted in the fuselage:
The stand-alone, cut-away, VIIB Lion engine, is still under construction, but the overall appearance is shown here, below. The center cylinder bank will highlight the twin overhead cam shafts that operate four valves per cylinder. As on the prototype, each valve has double return springs. The left cylinder bank will show the four pistons in that bank. And one piston in the center bank is visible through the cutout in the cylinder wall.
There is still work to do as the ignition wires have yet to be connected and some bolt heads need painting, but so far so good.
Napier Lion Aero Engine
The Supermarine S.5 was powered by the VIIB version of the Napier Lion aero engine. The Lion engine had a W-12 arrangement and was the primary power source for the UK Airforce from 1918 to the mid 1930s.
Major modifications were made to the VIIB engine to lower its profile and help reduce drag. The more normal XIA version powered the Napier-Railton race car.
