locomotive engineer license

During the year 1930 there was one engine which as on hype named as 'Ricardo' sleeve valve engine. Mirrlees the period introduced two Mirrleesengines represented this patent type of the valve engine. Well the first kind had bore of around 5.5 inches and developed a stroke of just about 6.5 inches and produced 20BHP each cylinder at rate of 900 r.p.m. the other had 17 inches bore and 21.5 inches stroke, giving 50BHP per cylinder on the rate of 200 r.p.m.