The engines built from a quiet purr to a bone-deep, bass rumble, more felt than heard.

Of the 342 engines built only two have been preserved.

Twelve engines ordered in 1905 and built at Cowlairs in 1906-07.

Twenty-two engines built between 1917 and 1920.

The last and 2,115th, engine built during the war, number 42 2580, left the factory on 9 March 1945.

The engine proved extremely popular with fleet operators, and built a strong reputation for reliability and longevity.

Engines will be 2 litre (2000cc) restricted engines also built between 1981 and 2005.

Six mobile engines for each legion, already built.

This was 1800 hp triple-expansion four-cylinder engine built in 1906.

MU-2D with 90-gallon tip tanks and upgraded engines, three built.