Re: (erielack) Air pump placement

[Richard Young <ryoungceo_@_yahoo.com>]

	Getting caught up on email and thought I'de interject
on this one. Air pump placement was mainly dictated by
space due to mechanical constraints on the engineers
side. The linkage involved with a "Johnson Bar" and
later power reversers takes up all of the right side
of a locomotive. There is no way to effectively cram
in another appliance that would clear all of the
direct connected linkage to the valve gear. And why
would you try to mechaniccally engineer a way to
connect the likage differently just to put the pumps
there when they can be located anywhere on a
locomotive.

	Pumps were mounted by different railroads all over
locomotives ( Left side , pilots , on top of boilers,
under cabs, on smokeboxes) anywhere they could plumb a
steam line in and an air line out. Some short lived
placements were even put on tenders but maintenance on
the flexible steam lines prove to unreliable and
costly ( steam connections leak and ultimately the
pumps would fail causing constant replacement of
flexible joints).

	Though mounting them on the left created the
"balanced" look it was mearly for convienience of
maintenence. Mounting them on the smokebox was most
efficient as it kept them cooler for better air output
and cleaner air input.

Sorry, SGL !

	Weight has almost no bearing on it when you look at
the over all weight of an engine verse the weight of a
pump you are looking at .5% to 1% of the total weight
of the locomotive. The only constraints in mounting
appliances is in how the boiler is engineered and
proper hole placement to allow it.People would be
suprised if they knew exactly wow many holes there are
in a boiler. With working on NKP 765 this last weekend
,which is completely stripped right now, there are
probebly over two hundred studs in the main boiler
corses. With removing most of them it looks like is
has been hit with .45 caliber buckshot. Calculating
all of those holes placement , the thickness of the
plate metal, spaces between holes, PSI , tensile
strength  etc...  determines the placement  or weight
allowed to be place or hung on a boiler in any given
area. If you look at the SP 4449 , on the firemans
side you have Not only two air pumps side by side but
also a Worthington Hot water pump to boot. Also all
three are about 1800 pounds each verses the right with
only the power reverser at about the same weight all
hung off the boiler.

Rich Young

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