Maintenance of a Steam Locomotive
For the personnel of the train the arrival to a terminal station did not mean the end of their task. Once the train was empty of passengers, lugagges and postal bags, it should move backwards towards a secondary track. Here the locomotive would be disengaged and sent to a pit where the fire box would be emptied without any danger, and then the machine would be entrusted to the maintenance team. Only after having delivered a complete report about the conditions of the travel and the performance of the machine, the workday of the personnel of the train could end.
Despite of its imposing size, a steam locomotive was a precision machine whose mechanical parts suffered from dirt, attrition and rust. Thus, the first task of the maintenance team was to clean the machine from end to end. With the help of long-handled pokers they scratched the grill to remove the soot, which could obstruct the air intake or block the valve. They removed, by using steam, the soot from the tubes of the boiler, cleaned the smoke box and checked that the exhausts and the stack were not obstructed. Every joint had to be inspected and replaced if necessary, for any fall of pressure in the braking system would endanger the whole train, and any defective injector could reduce the amount of water in the boiler, to the point that the fuses on the ceiling of the combustion chamber melted, stopping the machine.
To ease the cleaning of aerodynamical locomotives, the frontal part of the bodywork could be opened to access the smoke box. Scratchers and oil cans had diverse forms according to the needs and preferences of machinists and stokers.
Apart from the daily maintenance of the locomotives, these were periodically subjected to a full disassembly, and every ten years the Inspection of Mines effectuated a complete verification of the machine, before granting the license of circulation. It was not strange that a well built and carefully maintained locomotive became quinquagenarian or even octogenarian.
Every locomotive, and also those that belonged to a series, was individually built and each of its mobile parts was numbered, like those of a brand watch. Unlike what was done in the industry of the automobile, where defective parts were discarded and replaced by new ones, in the railway industry a worn bearing or a bent connecting rod were minutely repaired in the well equipped workshops of the company, to be installed again on the locomotive. The workshops were noisy caverns were long rows of drilling and milling machines, lathes and foundry benches lined up next to huge crane bridges capable of lifting machines of 100 tonnes with as much ease as if they were baskets of provisions. There worked men of extraordinary skill, mainly boiler and pipe specialists, for everything depended on the boiler.
For the railway crews around the world the great difficulty was the supply of non-calcareous water. Before heading to the desertic regions of the austral Africa onboard a powerful Garratt locomotive, the crew should not forget to fill the water tanks of the tender.
The two main risks that a machine had for effectuating its steaming function were the soot in the interior of the tubes and the calcareous deposits in the exterior. To clean the network of tubes by means of scratchers and brushes, and then a jet of water or steam, was indeed the dirtiest task, but it was more grievous the task of breaking the dozens of kilograms of calcareous crystallized sediment, hard as stone, which accumulated around the tubes. These two operations were essential, for a deposit of calcareous salts around the tubes grouped next to each other impeded the free circulation of the water, difficulting the diffusion of the heat. Besides, these salts had a corrosive effect which could affect the metal, forcing to effectuate much more important reparations which required the immobilization during weeks of the locomotive.
The machinists knew very well this danger and for preventing it they had a secret method which they considered infallible: to add oak bark to the water on the tank. These practices could be useful, but it seems that some mechinists went further... A certain day, in the water tank of a locomotive which had towed a convoy through a mountainous region crossed by rivers, the inspector discovered a colony of trouts. Not surprisingly, he reproached the machinist about the strange discovery, who impassive just answered: "But sir, that is my personal recipe for preventing the calcareous deposits!".