One place is near the cab, where there always seems to be a small line of steam. What is the purpose of this?
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Yea the steam turbine / generator / "dynamo", and perhaps the injector exhaust (the injectors used to add water to the boiler from the tender). It may be just steam or some mixture of steam/water; it sounds like it's a tricky procedure to get the right combination.
Note the injector exhaust below the cab, some blowoff out the low-pressure safety valve, and the inactive generator:
Now the generator is on:
And the air brake pumps also have either some adjacent exhaust or may be leaky (most of this exhaust seems to go up the main stack on the EBT locos), which you can see on the 2nd loco in this double-header:http://www.youtube.com/watch?v=lggjMWj35wc
When the locos get worn I assume everything leaks. On one of the trains I rode last summer in colorado, I ask the engineer about steam coming out from around the pistons and he said the seals were worn out. They do the repairs in the winter. The poor thing leaked so much I didnt think it make it back up the grade.
Happy railroading.
Lee S.
Don't assume that all of the steam venting from various places on a locomotive are leaks. Sometimes there are other reasons for venting steam. From front to back, here are the places I commonly see steam venting and why:
Cylindercocks - Two on each cylinder.These are opened before starting to move the locomotive and remain open until all condensed water has been drained. Then the valves are closed and all steam is directed to the stack. They may also be opened when running if the engine has been drifting - prior to opening the throttle again. (They are also effective in preventing "mooning the train".)
Valve rod and Cylinder rod packing - These packing glands will start to wear with time and may leak. We never touch them when hot to prevent a catastrophic accident. However, we do inspect and tighten them during the monthly boiler wash.
House valves - These drain valves are opened when the locomotive is not being used (generally in the engine house - hence the name) to drain condensate from the steam lines to each cylinder. We close them each morning after moving the locomotive out of the house.
Smoke box drain - Not all engines have one but this is useful in draining condensate from the smoke box to prevent corrosion. One wants the smoke box to be as dry as possible.
Foward boiler washout plug -I have never seen this one leak as it is tested during hydrostatic testing but it could.
Steam dome applicances -The whistle and several pressure relief valves are on the steam dome. Since the whistle is frequently operated, it is common to see a little steam wafting around it but the valve must be opened at least 30-40% to produce sound. The pressure relief valves (at least 2 - sometimes 3) vent when the boiler pressure exceeds the valve setting. On the Jupiter one valve is set at about 155 psi and the other at about 165 psi. We operate at about 145 psi so popping the 1st safety happens occasionally and is no cause for concern. Popping the 2nd safety is a big deal. Both relief valves may also leak a vent a small amount of steam. We try to avoid that because the venting steam may erode the valve seats.
Air pump - just like the cylinders up front, these have condensate valves and valve packing. We open the condensate valves when standing and close before tunning but after the train line is at pressure.
Dynamo - neither of our engines have one - we use kerosene lamps. But most engines do and these will run constantly.
Power reverser - neither of our engines have one but these are steam powered and will have condensate valves and valve packing. Out Johnson bars are about 6 feet long to give sufficent reversing leverage.
Aft Boiler Washout plug - these are located on the mud ring (lowest part of the boiler) and are tested during hydrostatic testing.
Boiler blowdown valve - Also located on the mud ring (often under the cab). Depending on operation - the blowdown valve is opened every few hours to get mud and solids out of the engine. Since solids pass through this valve - it is notorious for leaking. We rebuild this valve once a year.
Injectors - It takes steam to make steam and the injectors use steam pressure to inject water from the tender into the boilder. Since these are used frequently they often leak both steam and water. But they also vent steam and water in use.
Trycock drain - These are a series of 3 valves one above the other on the backhead of the boiler and are used to check boiler water level. If you get steam, the water level is below the valve, If you get water, the water level is above the valve. These valves drain below the cab so you may see steam from the drain.
Water Glass drain - The glas is used to check boiler water level with a drain below the cab. The fireman blows down the water glass to clear solids and to make sure the glass is reading correctly.
Tender and water line heater - A steam line is connected to the tender and the injector feed line to prevent freezing in the winter. This is used sparingly because cold water injects better than hot water but this will be a source of "winter steam ambiance".
More modern engines will have other steam operated applicances - but these are the most common sources of the steam you will see.
PS - the steam leaks are also the reason I always wear long sleeves and gauntlet gloves.
dd
When it is REALLY cold,outside,steam leaks from EVERYWHERE on a steam engine!
All the appliances can leak, especially as they get worn.
Other times things can appear to leak would be on shutdown. With a few exceptions, everything that was opened is closed to save pressure for starting up the next day; and everything that was closed is opened, to drain while condensation occurs overnight. This creates many paths for steam to vent.
espeefoamer wrote: When it is REALLY cold,outside,steam leaks from EVERYWHERE on a steam engine!
Actually the steam is also leaking on hot days - it just isn't a visible. That is a problem for maintenance. What you can't see can still burn you.
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