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  • Southern Pacific SD45 In 1:29 Scale

    by John Welther

    Photos by the author

    Model Railroading - August 2005 - Page 22

    It's almost hard to believe that EMDs SD45 was first introduced about 40 years ago. These locomotives have always portrayed sheer muscle to me and one might even say they are the "Granddaddy" of super-horsepower diesel locomotives of today. For a long time the SD45, with its 20cylinder 645 prime mover producing 3,600 hp, was considered the most powerful single engine locomotive in the world. Total production of these locomotives exceeded 1,200 units. Although its rare to see an SD45 in mainline service today, many have gone through extensive rebuilds over their career, and some still serve in lease companies and regional lines. Morrison-Knudsen purchased a number of used SD45s and rebuilt them to Dash 2 specs, while still retaining their exterior appearance, and employed them in their Motive Power Industries (MPI) lease fleet. That a few are still in service is a testimony to the durability of this powerful workhorse.

    The Southern Pacific had perhaps the largest fleet of these engines, purchasing over 300 units from 1966-1970. SP's SD45s performed all kinds of duties for this carrier ranging from hotshot freights to helper service. Sometime in the late 1970s SP started what they called the General Rehabilitation and Improvement, or simply, GRIP. All locomotives that were due for major overhaul at that time were considered candidates for GRIP. Most of these overhauls and rebuilding's were performed at SP's legendary Sacramento Shops. Locomotives that went through the program, including the SD45s, were usually renumbered. All SD45 GRIP graduates were designated SD45R and were renumbered in the 7400 series. By the late 1980s there were still some unmodified SD45s in their original number series in service. In most cases the SP decided to eventually retire these older units that had been in service over 20 years without a major rebuild.

    Due to the numerous rebuilds and overhauls the appearance of the locomotives could change a number of times from their original appearance. At least four paint schemes were applied at different times while the SD45s still served the SP. The early orders came painted scarlet and gray with their road number applied to the nose of the short hood. This eventually gave way to the road number being replaced for a short time with a Roman style SP which ultimately evolved to a Helvetica style. Some units also received the ill-fated SPSF merger scheme referred to as Kodachrome by the railfan community. A few SD45s received the SP "speed lettering" scheme.

    "G Scale"

    The popular term G scale has become a confusing, catchall, category that basically relates to models using a common track gauge of 45 millimeters. This gauge has been around since at least the early part of the last century. It was originally categorized and often times referred to as Gauge 1. It has been associated in the past with early manufacturers such as Ives and Marklin.

    A standard gauge (4' 8 1/2") model running on 45mm gauge track would be 1:32 scale. A 3' narrow gauge model using the same gauge is 1:20.3. Other popular scales that share the 45mm gauge today are 1:24, 1:29, and 1:22.5. All these other scales have helped add to the confusion of G scale. Some groups have tried to remove this confusion by using a prefix designation category known as LS that stands for Large Scale. Models in 1:29 scale are termed LS29, 1:24 is LS24, and so on.

    So now one might be ask why 1:29 scale? The short answer is 1:29 scale is exactly three times the size of HO. The manufacturers that pioneered 1:29 scale realized that most published plans for models are done in the popular scale of HO. This lent the plans to easily being resized for a larger scale of 1:29. Although, as I stated earlier, 1:32 scale would be the correct size for standard gauge equipment on 45mm gauge track, 1:29 scale is only slightly larger. According to my 1:29 scale ruler the track gauge scales out to be 4' 4 1/2". Thats a scale 4" shy of the proper width for standard gauge in this scale.

    Thus when viewing a 1:29 scale model on 45mm gauge track the difference is quite minimal at best. In other words, the models look right and create a satisfactory scale look as much as any scale model. As this scale gains popularity Ive no doubt we'll soon see something evolve like Proto 29 where the models can be converted to 4' 81/2" gauge in 1:29.

    Model Railroading - August 2005 - Page 23

    Aristo-Crafts SD45

    When I first saw the pre-production photos of Aristo-Crafts 1:29 scale model of EMDs SD45 I couldn't believe my eyes. I seriously thought I was looking at a model that was actually HO scale with some Cannon & Company items added to it. I soon learned how wrong I was. Overall the model is an excellent portrayal of its prototype. In this scale the model truly conveys the mass of the real locomotive.

    The detail of the model as it comes from the factory is quite exquisite. The power for the model is provided by four can motors (two per truck) with ball-bearing drivers. The front and rear headlights and class lights are directionally functional, and the model also includes operating walkway lights. The lights can be turned off if the model is serving as a trailing unit in a multiple-unit lashup. The model is at least as good, both in detail and operating performance, as any of the finer models presently offered in HO.

    Modeling an SP SD45

    The first thing done was to disassemble the model into subassemblies. The models superstructure is attached to the walkways with several screws below the chassis. Their locations are marked with arrows cast into the frame eliminating the guesswork. The superstructure can then be broken down into subassemblies. The subassemblies consist of four main components. These components are the long-hood engine compartment, cab, cab sub-base, and short hood. The sideframes were also removed from the power trucks.

    This was my first attempt at going all out on a 1:29-scale model. All my experience in building HO diesels for the past 20some years would be applied and put to the test on this model. Most importantly I gathered as many photos of the prototype that I could find. I consider this to be the most important tool a modeler can have when building prototype models.


    I typically start at the bottom and work my way up when working with locomotive models, and this one was no exception. The first thing I wanted to change on the model was its sideframes. The model comes with an early version of the EMD Flexicoil truck sideframe. It has three brake cylinders in the high-mount position. Photo 1 shows the stock sideframe.

    I wanted a sideframe that was more typical of some of SP's SD45s. I chose to modify the models sideframes into a later version with two brake cylinders in the high-mount position, thus omitting the middle cylinder. Each brake cylinder casting is attached to the sideframe with a small screw. All of the brake cylinders were removed from the models sideframes. By studying photos of the prototypes sideframes I determined what areas needed to be modified on the model. Photo 2 shows a stock sideframe with the areas to be removed and modified. Those areas are highlighted in gray primer. The removal of these items was done with a hobby saw, chisel blade and file, then sanded smooth. Photo 3 shows the sideframe with the items removed.

    The mounting studs on the back of two brake cylinders were removed and each brake cylinder was cemented to the sideframe. Each one was positioned over the center of the outboard journal bearings. The outboard ends of each brake cylinder were drilled in the center, and brake piping was bent from 1/32" brass wire and applied to each sideframe. The hole where the middle brake cylinder was attached was filled with a thick CA and given a few spritzes of CA accelerant. Once the CA hardened the area was sanded smooth.

    Slack adjuster rods for the brakes on the truck sideframes were fabricated from .093 Evergreen styrene tubing and .047 rod. The tubing was bored out slightly to accept the insertion of the styrene rod. Careful study of photos of the prototype revealed where to attach the slack adjusters on the models sideframes. The proper orientation of the slack adjusters should be given special attention when applied to the model.

    There is a beam that runs between each of the wheel journals. These beams have mounting brackets that attach to the brake shoe apparatus. These brackets aid in the positioning and travel of the brake shoes. The beams on the model were made of .030 x .060 styrene strips, and the brackets were made from pieces of .100 styrene channel stock. Each beam has brackets (one for each brake shoe assembly). Photo 4 shows these items applied to the sideframe.

    Sanding lines were made from .020 brass wire. The sanding line brackets were made from scrap pieces of photo-etched carrier material from an HO detail set. This material has a little spring to it and withstands a periodic derailment should it occur. These details were attached to the sideframes with CA adhesive. The left front sideframe has a J.M. Enterprises white-metal speed recorder casting applied to the center journal. Photo 5 is a view of a completed sideframe applied to the model.

    Model Railroading - August 2005 - Page 24

    Frame and Fuel Tank

    There are two brake valves that hang from the underframe. One is located over the left rear truck and the other is over the right front truck. These were fabricated with .020 styrene pieces and 1/16" diameter brass wire (see Photo 6). The fuel tank overflow pipe was also made from 1/16" brass wire. The support bracket on the fuel tank fillers was removed and the area was sanded to blend in with the fuel tank.


    The model comes with footboard pilots and injection molded plastic air and MU hoses. The footboards are attached with screws from the backside of the pilots. These items were removed from the model. The elbow fittings for the MU hoses were left on the pilot faces and were drilled to accept small pieces of .020 brass wire to enable applying MU hoses made from electrical wire insulation. The end of the hoses received white metal castings of gladhands made by J.M. Enterprises. The air hoses angle cocks are another casting from J.M. Enterprises. The bottom of the rear pilot face received a sheet metal plate made from.015 styrene. The styrene plate was drilled to accept .020 brass wire applied with CA. The ends of the wire were rounded off with a file to simulate rivet heads.

    The stock coupler cut-bar and long grabiron across the face of the pilots were removed. A new cut-bar was fashioned from 1 /16" brass wire. The cut-bar is made in three pieces like the prototypes. Photo 7 illustrates these steps on the model.

    The model has working drop steps at each end. MU power cable hangers were made from 3/64" brass rod and attached to the underside of the drop step. MU cable boxes were made from .010 styrene strip and applied to the protruding walkway area of the pilot faces next to the drop step. The MU junction boxes are a stock item on the Aristo-Craft model.


    The model comes without a snowplow. SP's SD45s all had snowplows. Many had plows on both ends when new. Aristo-Craft has a plow on their 1:29 Dash 9 that I had considered using. Its quite similar to the SP plows but too narrow. Digging through my paint and lettering diagrams I found a plow that was quite similar to what I was looking for. I enlarged the drawing on a photocopier to 1:29 scale dimensions. The plow on the drawing was cut out and applied to a sheet of .040 styrene sheet with a spray mount adhesive. Following the outline of the drawing the profile of the plow was cut out from the styrene sheet. When finished with the basic cutting the photocopy was removed but not before tracing an outline for the MU hose doors on the plow face. To give the plow curvature the styrene piece was immersed in boiling water to make it pliable. Next the piece was rolled with a piece of 1" diameter pipe. This was done a number of times until the desired effect was achieved. The MU hose door openings were then cut out from the plow face. A line was scored on the centerline at the rear of the plow. This enabled the piece to be bent back into a V-shape. The MU doors were cut from styrene sheet and applied at the appropriate location and .047 styrene rod was used to simulate the door hinges. Grabirons at the top of the plow were made from 3/64" brass wire. Sprue from a plastic kit was used to make mounting lugs for the plow. The holes for the footboard on the front pilot were enlarged to accept the mounting lugs. Photo 8 shows the results.

    This view shows the nose light package, toilet vent and class light blanks.
    Model Railroading - August 2005 - Page 25

    Body Detailing

    When it comes to aftermarket detail parts for 1:29-scale diesel locomotive models there isn't a lot to choose from at this time. However there are a few pioneers in this area. One of them is John McGuyer, owner of J.M. Enterprises. He has a line of cast, white metal detail parts for 1:29 and 1:32 scale railroad models, which is distributed exclusively by Ozark Miniatures in Cedar City, UT ( I have used as many of these parts on this model as possible. Other parts have been scratchbuilt. The dimensions for the scratchbuilt items were primarily taken from HO detail parts I had on hand and these dimensions were converted to 1:29 (3 x HO).

    The electrical cabinet behind the cab on the left side was made from .015 styrene. The base brackets are styrene U-channel, and the brace that attaches the cabinet to the back of the cab was made from .010 x .030 strip styrene (see Photos 9 to 11).

    There are two types of fan housings on the roof of the SD45s long hood (engine compartment) section. There are two lowprofile and three high-profile fans. The model has the opposite of what the prototype has. I placed the low-profile fans in their correct location over the dynamic brake section. For the high-profile plans I attempted to get a third fan housing from Aristo-Craft but got no results. One evening while perusing one of my books on SP diesels I discovered an SD45 that had been re-shopped with two high-profile fans and a low-profile one at the rear. This is the configuration I used on my model. If the chance ever comes for me to get another high-profile fan housing I will change it out.

    While working on the details of the roof area of the engine compartment section I fabricated a dynamic brake vent from styrene pieces and applied it to the proper location on the model (see Photo 12).

    The class lights and numberboards were removed from the rear of the long hood section. SP SD45s never had rear numberboards, and the unit I was modeling was circa 1980s after these locomotives had been re-shopped and had their class lights removed. Class light plugs were made from .010 styrene. Since I operate a laser in the real world I cut mine on the laser. In the past I used a leather hole punch to make an item like this. The blank inserts for the numberboards were produced on the laser as well. They could be cut by hand and have their corners radiused as well, but the laser is faster and more accurate. I know, its cheating, but we use what we have, right? Many commercial shops will do custom cutting if a CAD file is provided. A recent article in the Narrow Gauge & Short Line Gazette describes this in depth. The company I work for will provide the same services so its not necessarily out of the realm of the average modeler.

    SP locomotives generally had a large array of lights, some at both ends. Most had headlights on the cab as well as a light package in the nose of the short hood. The front light package usually had a red warning light (for when the locomotive went into emergency) and dual headlights. On the model a notch was cut into the nose to accommodate the light package. A box-like structure was made of .015 styrene and cemented into the notch. I took measurements of the dual headlight at the rear of the model and made another one from .020 styrene. The red warning light is a detail casting from J.M. Enterprises. Photo 14 shows these items applied to the nose of the model.

    View showing burnt area of hood.
    Model Railroading - August 2005 - Page 26

    A short while after the model was finished, John McGuyer was generous enough to send me quite a few samples from his detail parts product line. Among them was a very nice casting for a dual headlight. Were I to do another SP nose light package again I would use this casting rather than the part I made.

    A toilet vent was made from .010 styrene with a piece of .047 styrene tubing for its base. The vent was applied to the top of the short hood. The nose also received class light blanks.

    Cab Detailing

    The model comes with a full interior that features three seats and a very nice rendition of an EMD control stand. It also has the traditional Institution Green painted on the walls and ceiling. One drawback to all this is that the cab doors are molded in place and cant be opened to reveal some of this detail. The side windows of the cab are functioning, however.

    I removed the cabs front and rear window castings and the windshield wipers all around. The bell on the underframe was also removed so it could be mounted on the cab roof per SP practice. It is attached with a small screw. The bell is air actuated via an air pipe attached to the top of the bell. I used three small pieces of brass strip for the bells support brackets. These were glued to the inside of the bell. The bells airline was fashioned from 1/32" brass wire. A large drop of CA was built up at one end of the wire to simulate the airline connection at the top of the bell.

    A whip-style antenna was added to the roof of the cab. The base was made from a discarded brake shoe bolt from the sideframe modifications earlier. The antenna was made from .015 music wire. Photo 16 shows these items in place on the cab.

    A Nathan M-3 Air horn set from J.M. Enterprises was used to replace the stock 5-chime horns that came with the model. The bell and trumpet portions of the metal castings from J.M. are a little too large but are so nicely done otherwise I couldn't resist using them.

    A pair of cab sunshades was added. These were a spare set that came from an Aristo-Craft Dash 9 detail package. J.M. Enterprises also has them in their line of detail parts.

    The front and rear cab windows were replaced with laser-cut acrylic pieces. I manufacture these as a commercial item to the public. They are part of the small product line Ive started for 1:29 and 1:20.3 scales. The laser-cut windows are pre-masked, and on one side the mask is scribed for a window gasket effect. A fine brush and black paint can be used to paint the gasket or simply use a permanent marker. All of the pre-mask was left in place until the weathering and finish processes were complete. At this point the model was ready for touch-up painting and the final finishing stages.

    Weathering and the Scarlet Letter Process (Revisited)

    Model Railroading - August 2005 - Page 27

    Before I even started this project I’d already had it in mind to give this model my trademark “Scarlet Letter” weathering process. In the September 1992 issue of Mainline Modeler I did an article on modeling a Southern Pacific SD45 in HO scale. That was my first model to get what I call the Scarlet Letter treatment. In the January 1998 issue of Railroad Model Craftsman I wrote an article on modeling this process (this would be Scarlet Letter Process Version 1). The models in that article were two HO SD45T-2s.

    The process was meant to portray the blistered and peeled paint below the dynamic brake grids on Southern Pacific EMD locomotives. This resulted in the appearance that the locomotives had scarlet colored Southern Pacific painted on the sides of the locomotives because the white lettering faded away from heat dispersed by the dynamic brakes and revealed the red primer underneath. On the HO models this was accomplished with a technique I developed using decals. On a pre-decorated 1:29 scale model I decided to try something different.

    This second version of the Scarlet Letter Process involves water soluble paints rather than decals as in Version 1. I used Polly Scale SP Scarlet but any of Badgers fine line of MODELflex paints will work as well. Each letter was brush painted with the scarlet. The paint was applied heavily toward the top of the lettering, then several washes were applied to fade the red. Once the paint had dried I selectively swabbed various areas of the lettering with a cotton swab dipped in MicroSet Decal Setting Solution.

    The road number on the nose of the model was removed with several light passes of the back edge of a No. 11 blade. Final clean up of the area was done with a cotton swab dampened with alcohol. Helvetica-style SP letters were added to the nose. These were pressure sensitive vinyl die-cut letters I had made. Most small sign shops provide this service, and its not very costly. They usually have a sample book of type styles from which the customer can choose.

    The sides of the long hood were brushed with several thin washes of Polly Scale Rail Brown and Black. A heavier concentration of these wash applications was applied around details and door seams. The next step of weathering was applied with an airbrush. A wash mixture consisting of Roof Brown and Grimy Black, heavily thinned, was sprayed below the dynamic brake blister and around the area of the top of the letters. Several applications were done to achieve a "burnt" look from the heat dissipated from the dynamic brake grids.

    The areas around all the screens were masked, and the screens were sprayed with a thinned mix of Engine Black and Dust. The trucks, fuel tank, underframe and pilots were given a heavy application of what I call Road Grime. This is a heavily thinned mixture of Rail Brown, Engine Black, Grimy Black, Railroad Tie Brown and Dust. The balance of the model was given a light dusting of Road Grime. The roof of the model was given several dustings of a thinned wash consisting of Grimy Black and Dust. While all this airbrush weathering was still soft, the model was given dustings with pastel chalks. Particular attention was paid to prototype photos during the weathering process. The pastels were mainly earth tones. The area around the battery boxes was dusted with a pale yellow and black mixture of powder to simulate battery leakage.

    The model was given a few days to thoroughly dry before it was finally assembled and Kadee couplers were installed.

    Watching the finished model in operation gives me great pleasure and a feeling of a job well done. The model exceeded my original expectations when I started the project. The experience showed me that many of the things I learned from modeling in HO all those years paid off on this project. I learned a few new things as well. I will be doing quite a few more projects in this scale, as well as HO, and hope to report about them in future articles for Model Railroading magazine. I hope Ive shown a few readers that large-scale modeling can be taken as seriously as some of the smaller scales. If you'd like to find out more about diesel modeling in 1:29 scale, I invite you to check out the 1:29 Diesel Modelers on the web at

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