The Prototype
After a successful demonstration, the Southern Pacific ordered 15 model SD7 locomotives from the Electromotive Division (EMD) of General Motors (GM) on 4. April 1952. These featured a single 1,200 gal. fuel tank, Mars dual sealed beam headlights, and dynamic brakes. As delivered, these units were painted in the Road Switcher variation of what’s become known as the “Tiger Stripe” paint scheme. These were later repainted in “Black Widow” and had Mars signal lights added.
These were originally numbered 5279 – 5293, and classed DF-114 (DF being Diesel Freight). The 5288 and 5289 were ordered with 15 tons of extra ballast, and intended for helper duty on Cuesta (Coast Division, North of San Luis Obispo to Santa Maragrita California, about a 2.2% grade).
5288 and 5289 were put in service on 1. February 1953, so these would be very new locomotives on my future model railroad, set in 1953 over Cuesta. Thus, these two are a must for me to model.
The Model – Fuel Tank
My starting point is the original Life Like Proto 2000 (now Walthers Proto 2000) SD7, factory painted in the correct early roadswitcher paint scheme, but needing to be renumbered. There are also a number of issues that need to be addressed:
The biggest concern is that this order had a single 1,200 gal. fuel tank. There are Southern Pacific SD7s with a second 1,200 gallon tank, but this for water used in a short-hood mounted steam generator. Only the last 20 units (5316-5335, 20 units of class DF-118, to be discussed in a later part) had these features.
The second tank, as modeled by Life Like, then Walthers, and also by Broadway Limited, can not be simply cut away due to the structural limitations of the frame. However, Rail Power Products (RPP) (now Protopower West/A-line) has produced a frame for their SD7/9 shell that has a single fuel tank, with an optional plastic tank for those modeling dual tank SD7s and SD9s.
The fuel tank on the RPP frame is rather crude, while the fuel tanks on the Life Like model are fine injection molded plastic overlays. My solution is to mill the RPP frame to accept half of the Life Like plastic fuel tank.
To Be Continued
Other changes will include renumbering the shells to 5288 and 5289, of course, changing the factor cast Pyle dual sealed beam headlight for the Mars dual beam headlight as used on this order, adding other miscellaneous details, and equipping the models with ESU LokSound V DCC decoders. LED lighting will also be added for the headlights, number boards, ground and (possibly) step lights.
Stay tuned!