California's Railroad to the U.S. 1861 - 1996

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Model Train Help EBook

information page for modeling SP exDRGW EMD SD50 diesel locomotives in HO Scale

Construction of a Denver & Rio Grande SD50

By Andrew Hauser ©

This project starts out with a Railpower SD-60 shell, many detail parts and about 8 months of on and off modeling. After filing and sanding off the mold marks I glued under both sides of the cab a block of styrene. I stripped off all the parts from the Overland drive and fit just the frame in the shell. I located the styrene blocks and drilled a small hole through the frame into the blocks. The holes in the frame will be countersunk for a 1-72 screw and the blocks tapped to match. The next step was to reshape both front and rear anti-climbers. This was done by tracing a template from an Athearn GP-50, then transferring the trace onto a piece of 20 thou. sheet styrene. The template was placed on the anti-climbers and a line was scored with a sharp #11 X-acto blade, the rest was carved off and then dressed up with a file to match the template.

Next step was to fit the Cannon Thinwall Cab starting with the back wall, then both sides reinforced along the bottom and finally the front wall. The roof is then fit and only tacked in place, this is done to ease in its removal for the installation of the windows and lighting kit. The low hood has a DA DRGW style light mounted in a notch and backed with styrene blocks. Note: At the time of this construction Cannon did not have the sub-base kits out. You can use a sub-base kit and install the correct battery box doors on the base.


Body: Many makes of detail parts are used, not all are highlighted here but are on the attached list. On both pilots are working Detail Associates coupler cut levers installed in Detail Associates wire eye-bolts. Also on the pilots are OMI mu receptacles with the front having an mu-cable. The end of the long hood has DA grab irons mounted in # 80 holes and a DA dual headlight. The sides of the hood have DA eye-bolts, roof tabs, DW bell, and the side of the cab are working DA sun shades mounted in more DA eye-bolts. The top of the hood is detailed with PFM Q fans and a DA radio antenna with a piece of DA brass wire.

The handrail stanchions are from a Smokey Valley SD-60 handrail kit and the railings are hand formed from DA scale 3/4" brass wire. Each end walkway is closed off with a piece of chain mounted on two DA eye-bolts which are soldered to the stanchions.

Frame: An Overland drive is used with some added detail, the bottom of the frame has two 40 thou. square pieces running the length of the unit. Also added are two types of DW air filters sets, DA iron piping, DA air tanks, both the air tank and engine room have a drain pipe added. Added to the trucks were brake cylinder piping and a hand brake chain that is attached with DA eye-bolts.


These units were purchased new by the Rio Grand from EMD after testing a set of SD-50s borrowed from the KCS. The Rio Grand had originally order more SD-40T-2's, but this was changed after the testing the KCS units. All units are still working for their new owner on the Craig Branch in Colorado, and some have been repainted in SP speed lettering.

Finishing and lettering:

After all detail parts were added, the unit was washed in warm water using a household dish liquid and a soft 1" wide paint brush.

After drying the unit was primed using a 50/50 mixture of Floquil primer and thinner and the under frame parts were painted with Floquil Zinc Chromate primer. This was allowed to dry for a week and the ends were sprayed with a 60/40 mixture of Floquil SP Daylight orange and thinner. After drying for another week the orange ends were masked off, the body, frame and truck side frames were sprayed with Badger Accu Flex gloss black. After drying for about a week, the unit was sprayed with a 50/50 mixture of Crystal Cote and allowed to dry.

Microscale decals were used for all decaling requirements, including the end striping. After the decals had set the handrails were mounted, along with the window wipers and all detail painting was done. After drying, the unit was washed in warm soap and water and sealed with a 50/50 mixture of Floquil Flat Finish and thinner. The weathering was done with a mixture of weathering chalk and by airbrush using Floquil Grimy black, dust and mud. All weathering was again sealed with Floquil flat finish.

The only scratch building besides the couplers mounting pads and under frame mounting pads is the lighting unit. This unit was constructed on a piece of 1/2 x 1/2 square perforated board. On the perforated board are 6 diodes, three facing each way. This unit is connected to one side of the motor lead with a miniature connector. Two Sub miniature 1.5 volt bulbs are fit into the headlight housing, with the perforated board mounted to the inside roof of the cab. Both trucks can be removed from the unit by unplugging them from the top of the motor.

This article © Andrew Hauser 1996.

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Thursday, January 01, 1998 00:00:00 AM