Wood 3 is a Henschel truck fitted with a wood gasifier, a device to generate combustible gas by burning wood in a controlled way, then cooling and filtering the gas, which could then be used to power a combustion engine, in the same sort of way that LPG is used. This sort of technology was widely used in Europe during WW2 when petrol was scarce. This gasifier was produced by Menck & Hambrock GMBH of Altona, Hamburg.