In a message dated 10/10/02 12:35:31 PM Central Daylight Time,
cbqrr47@y... writes:
> Marshall
> In work train service with air operated equipment (air
> dumps, spreaders, rail loaders, etc.), the feed valve
> was set up to 110 psi, so-called "passenger air" and
> the throttle was set in notch 3 or so when the unit
> was stopped, to give plenty of air.
> John
>
Marshall, John -
Screwing the feed valve up to "passenger air" should have been used only when
the air operated equipment was buried in the train. Of course, in this
situation, anytime the spreader or air dumps were actuated, the brakes would
set on the balance of the train and you couldn't move until the air was
pumped-up (great move when you're on overtime). The ideal situation is when
the dumps or spreader are coupled to the engine, then the locomotive main
reservoir MU hose could be coupled and charge that huge air reservoir on the
spreader or air dumps. All the air-operated equipment I saw, had stenciled
on the air tank "Tested to 150 psi" and considering the locomotive MR
maintained between 130 & 140 psi air pressure, this was well within the range
of safe operation. The rear of the spreaders had two air hoses, one for the
trainline (brakes) and one for the reservoir (to control wings,
plow/flanger). The air dumps had three hoses on each end of the car; one
trainline and two reservoir hoses. Usually you see the two reservoir hoses
coupled together under the drawbar at each end of the car. A work train with
more than one air dump should have the reservoir hoses coupled between each
car and then to the MR on the engine for optimum performance. Each piece of
equipment had a valve between the reservoir and the trainline that determined
the source of air supply. Determining this source required a little bit of
effort/planning on the part of the person in charge of the work train. In
practice, though, be it a lack of knowledge or laziness, the locomotive MR MU
hose, generally, was not used, and the spreader/air dump reservoirs were
charged off the trainline.
Bob
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