In old steam locomotives, the true architect of their power wasn't the engineer. That rarely acknowledged role actually fell to the stoker.
Being a stoker didn't just consist of throwing shovelfuls of coal onto the fire. Their job involved constantly balancing numerous factors, such as the technical characteristics of the locomotive, the weight of the train they were pulling at the time, the route they were traveling on, the water level, and the quality of the fuel, to ensure that the boiler pressure was maintained at its maximum at all times, thus ensuring the engine could deliver its full potential without failing. Even shoveling coal was a science, as it couldn't be done lightly. The grating had to be covered as evenly as possible to prevent excessive accumulation in any one spot from impeding air flow and hampering combustion, or to prevent cold air from penetrating through any area that lacked it. Furthermore, depending on the size of the engine, this could be exhausting work. Renfe's "Santa Fe" locomotives could consume up to four tons per hour while arduously ascending the steep slope of Brañuelas (León).
As if all this weren't enough, at the stations the fireman had to fill the locomotive's tanks with water. He also had to check the multiple lubrication points on the connecting rods, ensure that the axle and connecting rod bearings hadn't overheated, and use a hammer and wrench to tighten any loose parts. In short, it was exhausting work that required the utmost attention, as any carelessness could result in a breakdown or loss of power, with the resulting delay in service.
Basque Railway Museum Euskotren
