The driver of a steam locomotive is the one in charge of “heating”. He takes care of the fire (lighting and maintenance) and the water.
The combination of these two elements produces steam and pressure. It is the steam pressure that enables the locomotive engineer to operate the locomotive. To cover the 14 kilometers of the line, the driver will consume around 250 kilos of coal. For a single return trip during the day, to the coal consumed on the line must be added what is consumed at standstill and during warm-up. Around a ton of coal will be burned for a single daily run! It’s not just a matter of throwing coal into the fire, but also of distributing it evenly over the grates to optimize combustion. As far as water is concerned, the operator has to ensure that the water level in the boiler is always above a minimum threshold, by feeding water into the boiler via injectors or a feed pump. A good quality fire and a good water level produce steam in sufficient quantity to keep the locomotive running smoothly.