The first steam engines were all stationary in kind, driving for example various smaller machines in the factories. It was not a problem to install a separate boiler next to the engine. When the steam engine developed further into driving trains, the train had to carry both enough water and firewood. These disadvantages precluded the steam engine from powering vehicles for the road. Additionally, there was a long waiting period before sufficient steam was generated.
How it works
The steam engine works with outer combustion. The steam has to be generated in the boiler, before it is - led by a special control - directed towards the correct side of the piston. (see the picture to the right) It is important to have a pressure relief valve, because the steam is capable of blasting the whole system.