Forno

Fireboxes is chambers found on steam vehicles , where fuel is burned in order to heat up water inside boilers .

Coal-powered fireboxes have a firedoor, which can be open to shovel coal inside. The door should be kept closed otherwise, to prevent blowback. Blowback is a dangerous event where exhaust flow is reversed, drawing fire into the cab , potentially catastrophically harming the crew. It happens upon entering tunnels with the firedoor open.

La temperatura all'interno del forno viene misurata tramite un termometro e dovrebbe essere mantenuta a un livello tale da permettere la generazione della quantità di vapore richiesta. Se la temperatura è troppo bassa, la generazione di vapore risulterà inefficiente, mentre un'eccessiva temperatura può portare a uno spreco di carburante.

Firebox temperature is controlled by the amount of coal and airflow inside it. Simply having no more coal to burn will cause the firebox to cool down, and adding more coal will warm it up if the airflow is sufficient. The amount of airflow depends on whether the steam is being admitted to the cylinders , but can also be adjusted by the blower and damper controls.

Having the firebox full to the brim with coal is not always the best choice. Too much coal with too little airflow negatively affects fuel efficiency , resulting in a lot of coal particles getting spewed out of the chimney before they’re fully burned. This is what makes exhaust dark. When coal amount is proportional to available airflow, however, it burns cleaner and the exhaust color is bright.

Per controllare più precisamente il livello di carbone all’interno del forno, il macchinista può utilizzare la pala professionale. Inoltre, è anche possibile scaricare il carbone utilizzando la leva di scarico del carbone situata accanto alla boccaporta.

Coal in fireboxes can be dumped manually, with the coal dump lever found next to the firedoor.