Re: Purpose of various steam locomotive parts

Lets see if I can help you, A blowdown is a Valve connected directly to the side of the Firebox on the exterior wall of the boiler. Its purpose is to remove any sediment that gathers in the bottom of the Mudring which is the lowest area of the Boiler around the Firebox, It is good to blowdown the locomotive regularly to remove any sediment. This keeps any sediment from gathering in the lowest section of the boiler and to prevent the Mudring or the lowest section of the boiler from overheating because of a lack of water reaching the walls of the boiler and side sheets of the firebox.. did I explain that okay..
We carry three or sometimes four oil cans, A long spout with a light oil, two oil cans with car or journal oil and one can over the firebox doors to keep it warm of Cyclinder oil, its a heavier oil we use in the Hydrostatic Lubricator in the cab... and works well to "Get You Home" if you have a warmer than normal Crown Brass box or journal Box on a Driver Wheel.
Now for tools, we carry two Crescent Wrenches, one about 10 inches to refill the Hydrostatic Lubricator if we need too, a larger Crescent Wrench, A Pipe wrench for replacing Air Hoses, about a 18 incher, A cheater Pipe for extra leverage, Pliers, a set of Channel Locks or adjustable pliers to adjust Wedges if need be, a set of srewdrivers for electrical work, a Hammer and a Mallet, and don't tell the shop guys.. a piece of sanding paper to polish the armature on the Dynamo or electrical generator if the lights get weak on the line and I probably missed something...
Now for the Dynamo, it does produce all the electricity we need and there is no storage battery, if the Dynamo goes out, thats it, no more power..
Now as far as repairs go, my engineers test required us to do just about anything to get home, from running with valve gear on only one side to using the Automatic brake valve in most amazing ways to removing rods... Thanks to great luck, the most serious thing I have had to do was jack up and block and replace pins on the Spring rigging on 463 in Osier... hope i gave you some good answers...