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  • Canadian Pacific SD40-2 with "Elephant Ears"

    by Bob Boudreau

    Photos by the author

    Kadee #5 coupler box mounted below pilot with styrene spacers (two .080 and one .020). Self-tapping screw adds a mechanical bond to coupler. Note rear of coupler box has been trimmed off so as not to interfere with the swing of the truck.
    Model Railroading - March 2005 - Page 26

    Canadian Pacific Railway had problems with its diesels operating in long tunnels in the western mountains, just as had the Rio Grande and Southern Pacific in the US. The problem was with trailing engines in a multi-unit lashup. The hot exhaust gasses from the lead unit would accumulate at the roof of the tunnel, and the trailing units would draw this hot air in for cooling their radiators. Too much hot air through the radiators would lessen their cooling abilities, and the diesel power plants would overheat and shut down. Not something you want in heavy mountain railroading!

    Southern Pacific's approach to this diesel cooling problem was to install hoods over the rear radiator openings on two SD40-2 engines, the idea being they would draw cooler air from nearer ground level in the tunnels. Canadian Pacific decided to try these large hoods in 1982, and they earned the nickname elephant ears by CP personnel due to their similarity with the large floppy ears on the big animals. The hoods were applied to two units, 5369 and 5340.

    While this experiment is supposed to have worked, the maintenance problems associated with the large hoods resulted in their being removed after a short period. On the Southern Pacific their experiment lead to the development of the SD40T-2 Tunnel Motors which had their radiator inlets close to the walkway.

    Since I have a thing for CP SD40-2s, of course I had to make an HO scale model of one of these elephant-ear-equipped diesels. The following is how I made my version.

    The Model

    A deceased friend of mine, Bruce Nett of Fort Fairfield, ME, used to make SD40-2 presentation models for Canadian Pacific that were given to retiring personnel and customers. Bruce used to buy Athearn SD40-2 kits by the case, and always had many on hand. Almost every time wed get together he would ask if I could use some of these undecorated dummy models, and I always took him up on his offers. So this ready supply of kits led me to make many models based on these SD40-2s. Many of my efforts would not have been made without his generosity, and for this I will always remember him. Thanks Bruce!

    These are the original Athearn blue box undecorated and unpowered kits, but any model of the SD40-2 could be used in this conversion, powered or not.

    Chassis -- I prefer couplers mounted on the body rather than on the chassis, as the Athearn clips often have a problem keeping the couplers on. I cut about a 1/4" off each end of the chassis with a fiberglass cutoff wheel in a Dremel motor tool. This allows space under the front and rear pilots for the body mounted Kadee couplers (see Photo 1). I built up a base for the Kadee #5 coupler boxes under the pilots with two layers of .080 and one of .020 styrene. The couplerbox top was glued to this built-up layer, and the coupler box itself and coupler were glued on and secured with a small self-tapping screw (see Photo 2). This modification allows the gap in the middle of the pilots to be filled with .020 styrene, greatly improving its appearance. A bit of the back of the Kadee coupler boxes was trimmed off to allow the trucks to swing properly. This modification does not hamper the operation of the couplers.

    The framework for the exhaust hoods is test-fit over the radiator; it is not glued on yet. Stanchions are temporarily in place as guides to determine how the hood fits on.
    Model Railroading - March 2005 - Page 27

    While the chassis was being worked on, the casting seams along the sides of the fuel tanks were filed and sanded down to give a smooth finish as on the prototype.

    Shell -- For the basic shell, most of the work involved adding various detail parts to bring it up to CP Rail 1980s standards. Using a #17 blade in an X-Acto knife, I carved off all of the cast-on grabirons on the front and rear of the shell, and sanded the areas smooth. New Details Associates (DA) grabirons were placed into holes drilled in the chassis. Don't forget the grabirons on the side and top of the short hood, and the large curved one at the top of the long hood, which I made from some brass wire. They were not glued in at this time, but were set aside to be added later when the shell was painted and decorated. Newer Athearn bodies have applied grabirons, and this step will not be required.

    CP Rail placed the locomotive bell above the cab between the numberboards, so the existing molded-on headlights should be filed off. I covered the area with a piece of .005 sheet styrene and then drilled a new hole for the Miniatures by Eric (ME) bell casting. A DA Sinclair radio antenna was glued to the center of the cab roof with Testors liquid glue. This completes the work on the cab.

    Since the headlights have been removed, new ones will have to be installed on the front of the low hood. I used a file to flatten an area in the upper portion of the hood, making the opening large enough to accommodate a DA Pyle headlight part. This was fastened in place with liquid glue. I drilled a suitable hole and glued in a brass horn casting on the roof just in front of the first radiator fan (the third one from the back). The horn is mounted on the firemans side of the roof, and is kept in place with some CA glue. The dual rear headlights were cut and filed off, with the resulting hole filled with plastic putty. When the putty had hardened, the area was filed and sanded down and a single ME headlight casting was glued on by inserting it into a drilled hole.

    These early Athearn bodies are kept on the chassis by unprototypical lugs that fit into holes in the body under the walkways. I filed down the lugs so they did not protrude beyond the holes. Then I covered the body holes with small squares of .005 sheet styrene. When the chassis is painted these are hard to notice, and do a nice job of hiding the attaching holes.

    The front pilot was detailed by adding a new ME CP pilot after the bottom of the plastic pilot was filed smooth. Other ME parts included ditchlights and lift rings, which were also placed on the rear pilot. To attach these brass lift rings, some of the plastic anticlimbers had to be cut off with a hobby knife. To ensure they were all glued on at the same height, I made a little jig with a piece of strip styrene and a piece of round solid tubing (see Photo 3). The DA drop steps were added to the front and rear platforms later, after the handrails were installed. That's it for the basic body changes and additions.

    The Hoods

    I decided to make the hoods so they would straddle the existing radiators on the SD40-2. Since the prototype CP Rail diesels had the small Multimark on the end of the sides, the hoods had to be made so they could be attached after the model was painted and decorated. Attaching them to the unpainted model would have made things too complicated.

    I made the hoods from .010 sheet styrene (see Figure). The length of the radiator cast on the model determines the length of the hoods. If you try this conversion and use a different SD40-2 model, it would be best to measure the radiator grilles to see if my dimensions are the same. To determine the depth of the hoods, I temporarily added several handrail stanchions in the area, as the hoods have to extend out beyond the handrails.

    The triangular-shaped sides of the hood were made first, and then pieces of strip styrene were cut to length so they would fit between the two side pieces. The exact size of the strip styrene used is not important; see Photo 4 to see the framework made to support the outer hood shell. I used the largest sizes that I had on hand that would fit without interfering with the outer hood body. Note the piece in the middle that keeps the outer strip from bowing in. Keep in mind that this framework for the hood is not glued onto the shell at this time, it is held on by friction only.

    Rear view of the hoods being test-fit. Note they are placed away from the radiator frame to show how they fit on snugly.
    Model Railroading - March 2005 - Page 28

    The outer sections of the hoods were cut from single pieces of styrene, with the three vertical lines scribed in the material first. I used the back side of a #11 blade in an X-Acto knife to do the scribing, and cleaned the resulting fuzz off with my fingernail. Scribing was done with several light passes rather than one heavy one. When these pieces were cut out from the main sheet of styrene, another scribe was done where the styrene would be bent to form the hood.

    Note these side sections do not go all the way to the top of the radiator; there is a flat area along the top that was filled in with a piece of strip styrene. After the newly made hood sides are glued onto the framework, thin strips of styrene can be glued on the bottom edge, forming an L one strip along the bottom, sticking out, and one above it. More strips of styrene were glued to the outer vertical edges of the lower hoods to stiffen them as well. This is similar to the prototype.

    The prototype hoods had four small hoops along the bottom edge of the upper portion; I assume these were pickup points used when installing and removing the hoods. I thought about making small loops from fine brass wire, but figured it would be difficult to make them all a uniform size. And drilling the small holes into which they would be inserted would require too much precision, so I opted to use some DA cast brass lift rings. They also make them in styrene, but past experience has shown they are very fragile and break too easy. I located the proper locations for the lift rings, drilled appropriate holes and glued them in place with CA glue. This completes the pair of "elephant ears" for the model.


    Usual techniques were done to complete the painting and decorating of the model. The shell, cab, new hoods and the chassis were all washed in warm water with some dish detergent. After they had air dried, I primed the plastic parts with Floquil Foundation and allowed it to dry for several days. The body and hoods were painted with Accu+paint CP Red, the chassis and truck sideframes with Floquil Grimy Black. I held onto the hoods with clamping forceps, holding the inner bracing. After the red had dried, the walkways and pilots were masked off and painted with Badger MODELflex Gloss Black. The end of the long hood was also painted Gloss Black. Quite a combination of paint types, but I used what I had on hand!

    As I mentioned at first, I have quite an interest in SD40-2s, and as a result of decorating quite a few in CP Rail colors I still have some Accu+cals decals on hand. I dont think they are still available, but Microscale also makes CP decals. The decals were applied to copy the prototype, including the smaller CP Multimark. I noted the prototype did not have the classification numbers below the cab number, so I did not add them. Stripes from the decal set were added to both ends. The rear of this diesel has the engine number within the stripes. In previous models Ive cut out the area from the stripe decals before applying them, leaving a black rectangle into which the number decals could be added. This method left the large decal with the stripe somewhat fragile to handle so I used a different method this time. The stripes were applied over the entire end. I have some decal sheets with large black stripes, so I cut out a section from these to make a rectangle into which the rear numbers would be placed. This black rectangle decal was placed over the top of the white stripes. When it had dried, the number decals were added.

    CP paints the top of the short hoods black to cut down the glare, and I did this by using Microscale decal panels made especially for this purpose. The area could also be masked and painted black if you choose.

    Preparing the front numberboards. They were left on the sprue, and brush-painted Gloss Black. Individual numbers from the Accu+cals decal set were used to make up the engine number, with the help of the third hand with a magnifying glass.
    Model Railroading - March 2005 - Page 29

    Diesel cab windows that do not open have black rubber gaskets around their perimeters. I simulated this by coloring the inner and outer edges of the model windows black with a felt-tip pen. This adds greatly to the visual appeal of the cab, making the windows more prominent. I also did the edges and inner portion of the numberboard openings before the actual numberboards were inserted. The clear numberboards themselves were left on their sprues and were painted Gloss Black. Applying the individual numbers to the numberboards has always been a chore, so I devised a new method. As can be seen in the photo, the painted numberboards were held rigid using a third hand clamp. The clamp came with a magnifying lens, which helped considerably! After the number decals had dried, the numberboards were inserted into their holes at the top of the cab.

    After all of the decals had been applied and snuggled down with Solvaset, they were gently cleaned with a paper towel and clean water to remove any residue glue. After the model was allowed to dry, it was sprayed with a coat of Floquil Hi Gloss as a protectant for the decals. The chassis and truck sideframes were lightly sprayed with Floquil Rust to simulate normal road dust. Some Rust was lightly sprayed on the couplers to give them an in-use look. I later applied some Bragdon weathering powder to the trucks and underframe to make them more prominent.

    The handrails and grabirons came next. DA grabirons were inserted into the previously drilled holes, and were kept at a uniform distance from the shell with a piece of strip styrene. They were kept in place with some CA glue applied from the inside with a toothpick. After the CA had dried, I used some small side-cutting pliers to cut off the portions of the grabirons that were sticking inside. This is especially important if you are using a powered chassis, as they may interfere with the mechanism.

    I apply the Athearn stanchions to the handrails, and when they are on the model I lightly squeeze the top of the stanchions to hold them in place. This doesn't always hold them securely, so I gently slide them sideways and apply a small drop of CA, then slide them back in place. After the end handrails and stanchions are firmly in place, I cut the handrail in between the two middle stanchions, as per prototype. The cut edges were then filed smooth. The drop steps and MU stands were glued in place, and were brush painted black.

    The grabirons, stanchions and handrails were brush painted using the same paints as were used on the body. The white handrails on the end were painted with Badger MODELflex Reefer White. This same paint was used to paint the edges of all the steps, an eye-catching detail. Some of the red paint was use to highlight the fuel fillers and gauges on the fuel tank. These diesels have rerailers attached to the rear trucks. I painted them yellow and fastened them on the sideframes with some Goop, a sticky glue that will fasten almost anything to anything.

    MV Products lenses were glued into the headlights, ditchlights and the rear headlight. This CP diesel has classification lights above the front number boards. To simulate these, I drilled small holes where they should go, and glued small MV lenses into the holes.

    I added some light weathering to the roof of the diesel with some Floquil Engine Black using an airbrush, mostly around the exhaust and fans. To keep the weathering mostly on the fans themselves, I used a plastic circle template as a mask - see photo.

    The last task was to fasten on the new hoods. I applied some CA in several spots around the inside perimeter and held them on while the glue set. And so an elephant ears diesel joins my fleet!

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