Branchline Pullman Underbody Variations
Copyright 2001 – 2010 Thomas C. Madden
All six Branchline
Pullman kits use the same body core - a one-piece molding consisting of two ends
and the floor/underframe. Bosses are molded for mounting a single 18” UC
brake cylinder and the UC control valve. Other underbody components can be
mounted as appropriate for the prototype. Included in all Branchline’s
Pullman kits are two 8-cell battery boxes, one APWS (air pressure water system)
water tank, one UC valve, one 18” brake cylinder with levers and rodding, four air reservoirs, and air conditioner
The supplied parts
will let the modeler construct representative underbodies. But not all possible combinations of brake
and a/c layouts can be modeled from the kit parts. Here are some helpful hints.
Brakes - cylinders
A UC brake system
with a single 18” brake cylinder was the most common one installed on the
Branchline produces, but there were many with two 16” brake cylinders.
The Milwaukee Road,
for example, specified two-cylinder UC systems on most of its heavyweight Pullmans. The Branchline
brake cylinder is actually closer to 16” than 18”, an apparent
misunderstanding of the specified cylinder size being the inside diameter, not
the outside diameter. UC brake cylinders from other manufacturers also have
this error. Underbody layout drawings for two-cylinder systems will be added to
this web site eventually. Two-cylinder brake systems also have different
numbers and sizes of air reservoirs than single cylinder systems.
Brakes – UC valve
The mounting lug for
the UC valve is correctly located for many cars, but not all. The easiest fix
is to make a new lug out of styrene and remove the molded-on one.
Brakes – air reservoirs
Branchline has molded
the Service and Auxiliary air brake reservoirs as a co-joined pair. This is fine for most cars with PM or PMB a/c
systems, but in most other cases the two were mounted in separate locations.
New tanks can be scratchbuilt, or the Branchline tanks can be cut apart and
mounted so the cut sides are not visible.
PM or PMB A/C
Highly accurate Pullman mechanical a/c systems with or without brine
auxiliary tanks can be modeled with kit parts. Pullmans
assigned to the New York
Central did not have brine tanks. PMB-equipped cars that were later reassigned
to the NYC had their brine tanks removed. Pullman
began removing brine tanks in late 1947, and by late 1952 they had been removed
from virtually all in-service heavyweight Pullmans.
Check the CCR database for the dates your model would have been equipped with a
Ice A/C – cold water sumps
Cold water collection
sumps are seldom modeled in HO, and the Branchline kit does not include one.
These were suspended from the center sills and were the lowest-hanging pieces
of equipment on the cars save for steam and air hoses. Pullman used three different sump designs.
The 1933 version featured an insulated tank that looked like an upside-down
rural mailbox hanging from the center sill, with the circulating pump mounted
nearby. The 1934/35 and 1936 designs placed the tank and sump into a common
rectangular housing. There were minor differences between these latter two, but
they are of little consequence on an HO model. New England Rail Service offers
a cast resin 1936 sump housing, part number 253. The 1933 sump has not been
offered as a separate part.
Ice A/C – battery boxes
Pullmans retrofitted with ice a/c systems usually
had both 8-cell battery boxes removed and replaced with a single 16-cell box.
Not a box twice as big as an 8-cell box, but one that was 10” deeper. No
one has offered this as an aftermarket part, but when viewed from the car side
it is identical to a standard 8-cell box.
tgmadden (at) worldnet (dot) att (dot) net