AS the name implies, this gauge shows the pressure inside the boiler. When a steam locomotive has been standing for a while, steam may condense in the cylinders as they cool. The resulting water, being incompressible, can result in damage to the cylinders and pistons when the locomotive then tries to move away. It is these that produce the typical large cloud of steam from the front of a locomotive when it first begins to move. Dampers The primary supply of air to the fire is from below, via the ashpan.
Dampers are the flaps, operated from the cab, which regulate the flow of air through the ashpan.
They also provided access to rake out clinker and ash from the ashpan. Firedoors Used to close off the firehole, thus preventing flames blowing back in to the cab. The doors are hollow and allow a small amount of air into the firebox above the fire even when completely closed. The operating lever, on the left hand door, slides both half doors in opposite directions simultaneously. The oil thus displaced is fed to the pistons and cylinders to lubricate them while the engine is in motion with the regulator open.