Heinrich Lanz HR 5

The register lists here 3 versions with a uniform 11 kW from the single-cylinder engine at rated speeds of 500 to 540 rpm. Unladen weights range from 2,650 to 3,640 kg, lengths from 3,030 to 3,130 mm, width is uniformly 1,945 mm and heights range from 1,335 to 2,200 mm.

With their high unladen weight against comparatively moderate power, Bulldogs such as the HR 5 stood for reliability and pulling power rather than speed; they worked on mid-size and larger farms, where cheap multi-fuel operation lowered running costs against pure diesel engines.

On a used example, the condition of the hot bulb and cylinder, tightness of the cooling, condition of the flywheel, and rust on chassis and mudguards after decades of use count; parts are available through specialist Lanz Bulldog workshops and vintage-machinery dealers.

The Lanz Bulldog's hot-bulb engine ignites the fuel-air mixture on a glowing head, preheated from outside with a blowtorch, rather than by spark plug or injection pressure; this principle tolerated variable fuel quality and enabled the machines' characteristic multi-fuel operation on crude oil, diesel or even vegetable oil. The single-speed 540 rpm PTO was the rule in this early period.