Hi Jonathan:
My guess on your steam blowing into the exhaust stream at the
stack...without seeing the photo... is that the steam is the exhaust from
either the feedwater pump or the air pump(s). Sometimes the air pump
exhaust is piped into one of the cylinder exhaust passages, sometimes
directly in through the side of the smokebox with the pipe directed up into
the stack, and sometimes outside the smokebox near the stack, exhausting
directly into the atmosphere.
The Coffin feedwater heaters were mounted essentially inside the smokebox,
it's a nasty, dirty, inconvenient place to have to work on one. If they
weren't a whole lot more effective than the "outside" types, they might not
be worth the trouble.
The difference between lifting and non-lifting injectors is that a lifting
injector will "lift" water from a level lower than itself. They are usually
mounted on the side of the boiler, either in the cab, or just in front of
it. The downside is that, if the injector...because of a steam valve leak
or leaking boiler check...gets too hot, it won't lift....then you are out of
business. An injector has to be cool enough that the steam will condense
into a jet and "pick up" the water to force it into the boiler. A hot
injector won't create the vacuum to suck the water into it. A non-lifting
injector is mounted down low below the cab, and if it gets hot, you can
flood it with water from the tender and cool it down so it will work. My
guess is that most modern power was equipped with nonlifting injectors
because they were less trouble, and easier to get at for service.
Best,
Mike Decker
----- Original Message -----
From: <BRHSlist@yahoogroups.com>
To: <BRHSlist@yahoogroups.com>
> Date: Sun, 10 Mar 2002 09:28:56 -0900
> From: jonathanharris@e...
> Subject: Re: Steam engine questions
>
> Thanks, John, for clarifying the relative merits of Elesco vs.
Worthington
> BL feedwater heaters. Can you or anyone extend this thread and tell us a
> little about the Coffin units? I'm curious because, to my knowledge, the
> Burlington had only three engines equipped with feedwater heaters of that
> type (all Ottumwa Division O-3s), and those units all were removed from
the
> engines relatively early. Why were they so unsuccessful?
>
> A related (sort of) question: Can you explain the difference between
> "lifting" and "non-lifting" injectors, and tell us why the Burlington
seems
> to have had so strong a preference for the latter?
>
> Thanks again,
> Jonathan
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