The unique truck we gonna tell you about appeared in 1949. People still remembered about severe war time when freighters had to perform their tasks with a shortage of liquid fuel - gasoline. Partially the problem was solved by gas-producer vehicles - heavy and demanding - they allowed to get gas for powering engines. However such vehicles were not efficient enough and engineers thought about steamers which were used widely abroad in the 1920-40s.
There was a serious conflict between the USSR and America in 1949. It's the very year when the USSR tested the first nuclear bomb.And it's when they were still building steamers powered by wood!
One Soviet institute was set a task to build a steam vehicle powered by wood. Nobody had ever tried to do that before.
Its lifting capacity had to be not less than 6 tons at its full mass of 14,5 tons including 350-400 kg of wood in its bunkers and 380 kg of water in the boiler. The maximum speed had to be about 40-45 km/h. Once it was fully fueled it could overcome the distance of 80 km.
Cycle diagram of the steamer.
The prototype for such steam vehicles was Sentinel S.4 from England.
The cabin for three was placed over the front axle, behind was a compartment with a steam power plant including the boiler. In the rear part the cargo bed was mounted.
The main power was tapped to the front axle. The gearbox had a direct and downshift gears with a gear ratio of 2.22. The downshift gear could be activated without full stop of the vehicle. The pedal effort was considerably reduced.
General view of the steamer.
To drive such a vehicle one had to be specially trained. All the machenism was very complicated.