CHARACTERS OF WW1 – LIEUTENANT W O BENTLEY RNVR

Most people have heard of Walter Owen Bentley’s achievements in the automotive industry. Not only did he found Bentley Motors (selling it to Rolls Royce in 1931), but he was later a design engineer for Lagonda and Aston Martin, too. However, in researching the sequel to my WW1 naval aviation novel, The Wings of the Wind, I discovered that Bentley had served in the Royal Naval Air Service (RNAS) during WW1 and designed two brand-new aero engines for the RNAS.

Bentley had already achieved success with the use of aluminium pistons in his car engines and he thought he could apply the same technology to aero engines. He expected that such modifications would enable aircraft engines to run cooler and with a higher power output. The Navy first sent him as a consultant to work with Rolls Royce and Sunbeam to help improve their engines, but the biggest supplier of aero engines at the time was the French company, Clerget. Britain manufactured Clerget engines under license in Chiswick. There his work achieved an extra 20HP for the Clerget engine, but Bentley discovered several design defects in the Clerget engines. The Navy tasked him to conduct the necessary Research and Development to design a new engine, but the manufacturer lacked the resources to carry out such R&D. Accordingly, the Navy set Bentley up with his own team at the Humber works in Coventry.

Bentley recognised that whereas in automotive engines a breakdown was an inconvenience, for the pilots it was a matter of life or death. The French engines tended to overheat after half an hour in the air and some pilots hated aircraft engine designers with a passion. Bentley’s solution was to ensure that none of his engines went into production before every possible test and precaution against failure had been taken. Moreover, he spent much time on the frontline in France talking in fastidious detail to both British and French pilots about their needs and frustrations flying in wartime conditions. In time, he developed the Bentley Rotary 1 engine, or BR1. This engine was fitted to the RNAS’s Sopwith Camels (or Bentley Camels as they were known to the pilots), but the Royal Flying Corps’ Camels were still fitted with French engines. Suddenly, the RNAS had a fighter capable of matching the Germans’ six-cylinder aircraft. Moreover, such was the reliability of the BR1, it became the aspiration of the naval pilots to be appointed to a BR squadron.

Bentley went on to develop a bigger engine, the BR2, and this was fitted late in the war to the RAF’s Sopwith Snipes. It was retired in 1928 as the RAF’s last rotary engine. Bentley was awarded the MBE for his war service and £8,000 for his inventions. In 1919, he went on to found Bentley Motors.

Bentley-Humber BR2