Recently realized that I never knew this !


M

MarkInLA

Guest
Hi. I've been into trains since the 1950s. So it's odd that I never questioned how the water gets from the tender to the boiler !! My guess is there's an impeller/pump under the tender with (flexible) steam pipes from cab to it. Water is then pumped thru another pipe back to the boiler..No ? Related: With a feed water heater over the smokebox, can I assume it's the same activity except for cold water traveling a longer way to it, then running back to boiler, preheated ? Thanks, M
 
Hi Mark.
There are two ways to feed water to the boiler. The main thing is that cold water is bad for the boiler and has to be pre-heated before it is added.
The most used way is with an Injector which uses boiler steam pressure to Inject water into the boiler. These are located on the loco and draws water from the tender via a flexible hose. The injector consists of a set of cones which form a path for the steam and water to mix.
The steam from the boiler trades pressure for velocity so even low pressures can overcome boiler pressure and even exhaust steam can be used with the right injector.
The water leaving the injector is at nearly boiler temperature so does not need further heating.
Where a feed water heater is used the cold water is pumped through the heater by a pump again on the loco and by pump pressure into the boiler. The exhaust steam used for heating is usually condensed and run back into the tender.
Hope this helps. Regards.
 
Most injectors just dump the water on the tack, not going back to the tender.
 
Most injectors just dump the water on the tack, not going back to the tender.
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Injectors do not return water to the tender - the water dumped on the track is overflow water and should be reduced or eliminated by balancing the water and steam controls. Only exhaust steam feedwater heaters return condensed water back to the tender in most designs.
 
There's water in the tender? You learn something new everyday. I thought it was all coal or wood and the water was up front.
 
Gregjl said:
There's water in the tender? You learn something new everyday. I thought it was all coal or wood and the water was up front.
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Yes, the part at the back, usually with a hatch in the middle, is for water. The part at the front of the tender is for coal/oil/gas.
 
bnsf971 said:
Yes, the part at the back, usually with a hatch in the middle, is for water. The part at the front of the tender is for coal/oil/gas.
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I saw a still photo years ago of a steam engine filling up with water and the pipe was over the front, in front of the cab. I guess they dropped the pipe prematurely.
 
Gregjl said:
I saw a still photo years ago of a steam engine filling up with water and the pipe was over the front, in front of the cab. I guess they dropped the pipe prematurely.
Click to expand...
Maybe what you were seeing was not water, but the sand dome being filled with sand ?
 
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