Branchline Underbody Hints

THE PULLMAN PROJECT

Branchline Pullman Underbody Variations

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 components.

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 Pullmans 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 brine tank.

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.

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Tom Madden

tgmadden (at) worldnet (dot) att (dot) net