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  • Upgrading the Trix Union Pacific Steel Cabooses

    By Steve Orth 
    Prototype photos by Bill Metzger

    The Union Pacific acquired its first all-steel caboose from Mt.Vernon Car Manufacturing in 1942. These 100 cabooses were designated as class CA-3. These cabooses were designed to UP specifications and were unique in their design, with a tall, centered cupola. The sides were constructed of riveted steel sheets. The roof was made of riveted panels with an Apex steel running board. As delivered, the CA-3 class had a running board on the top of the cupola, but this was removed in 1943 due to safety concerns. A cast plate inscribed with “Keep Off Cupola” was placed over the mounting areas. In 1944, 100 additional cabooses were purchased from Pullman Standard and designated as class CA-4. The CA-3 and CA-4 classes are virtually identical with the exception of the omission of the cupola running board on the CA-4. The cast plates were included on the CA-4s. The CA-3 and CA-4 classes have a ladder with an offset in it at the end rail location. The ladder stiles continue above the roof and are rolled over to connect to the ladder platform. These ladders provide a spotting feature for the two classes. Both the CA-3 and CA-4 classes were delivered with steel/wood composite “Q” trucks. The trucks on SO of the CA-3 and CA-4 cabooses were replaced in 1952 with all-steel trucks from GSC with an outside-swing-hanger design. In 1955, 11 CA-3 and 39 CA-4 cabooses were equipped with GSC inside-swing-hanger trucks. In 1958, 97 additional cabooses were equipped with the outside-swing­ hanger trucks, completing the replacement of the “Q” trucks.

    In 1952, 100 new cabooses were built by the railroad in the Omaha shops and designated class CA-S. The CA-S class was very similar to the CA-3/4 classes. The overall dimensions were the same, as was the underframe and side construction. The roof construction was altered to use StanRay diagonal roof panels in place of four of the Murphy panels. As with most new freight car construction in this era, the StanRay panels were preferred for their increased stiffness. The CA-S class had unique running boards manufactured by Transco. The Transco running board supports on the roof ends were triangular-shaped steel stampings with a triangular hole through them. These supports are a spotting feature of the CA­S class. The CA-S cabooses had a new, straight ladder design and a safety cage on the ladder platform. The CA-S class was the first class to use the GSC outside-swing-hanger steel trucks.

    In 1955, a second group of 100 cabooses were built by the railroad in their Omaha shops. These were designated as class CA-6. The CA-6 cabooses were nearly identical to the CA-S, with riveted sides and the same roof panel configuration. On this class, Union Pacific returned to an Apex steel funning board with the common steel support bars on the roof ends. The ladder is the same as the CA-S. The CA-6 class was delivered with GSC inside-swing­ hanger trucks and was the only class so delivered. Most CA-6s retained these trucks through out their lives.

    Beginning in 1974, Union Pacific modified several cabooses for pool service. The modifications included the addition of improved draft gear, safety windows, oil-burning stoves, electric interior lighting, an axle-driven generator, electric marker lights, retention toilets, and roller-bearing outside-swing-hanger trucks. Two CA-3 cabooses and seven CA-4s were modified. Several CA-5 cabooses were modified. No CA-6 cabooses were modified.

    The CA-3 and CA-4 classes were delivered in the standard oxide red with white lettering scheme. In 1947, all UP cabooses were repainted in the familiar yellow, oxide and red scheme. The subsequent classes were delivered in the yellow scheme. Union Pacific also added safety slogans to the sides of many cabooses beginning in the mid 1950s. The slogan board size, lettering and slogans changed over the years. No records have been found to document the exact slogan that was applied to any particular caboose, but photographs can be used.

    The Union Pacific Historical Society has published an excellent book, CABOOSES OF THE UNION PACIFIC RAILROAD, by Don Strack and James Ehrenberger. The book is an excellent source of data on the UP cabooses, including the earlier wood classes and the later steel classes’ design details, drawings, painting diagrams, and it includes hundreds of B&W and color photos. It can be purchased from the UPHS at www.UPHS.org

    The Trix (Marklin) Union Pacific Caboose Model

    Marklin has released a model of the Union Pacific CA-3 and CA-4 caboose. The model has been produced in the yellow paint scheme under the Marklin name and in the oxide scheme in the Trix name. Both cabooses come with nicely rendered “Q” trucks and accurate end rails and ladders. The Marklin caboose comes with electric marker lights molded into the cupola. The Trix caboose has the cupola without the marker lights. Both cabooses were erroneously built with flat panel roofs. While this was disappointing to many, it is this error that will allow modelers to build a caboose from any of the CA-3 through CA-6 c1asses-a case of “making a silk purse from a sow’s ear.” The caboose models also lack a centersill and come with either NEMA couplers or a Kadee Number 18 coupler that is designed to mate with the NEMA coupler socket on a swinging arm.

    Using the Marklin and Trix models, I kit-converted several correct models of various vintages, including a correct CA-3 in the post-1952 paint scheme, one CA-4 in pool service, two CA-5s, and one CA-6. Follow along and we’ll step through the process.

    Simple Roof Panels

    Using the UP drawings in the referenced book, I built seven Murphy panels for each CA-3 and CA-4 model. The panels were cut from .25 x .015-inch styrene strip, with each panel being 1.18 inches long as shown in Figure 1. The corners of the panels were given a slight radius with a file. The top edges of the panels were too square and also needed to be rounded off. To round them, I placed a 2-inch-wide strip of masking tape about 6 inches long onto my workbench top, with the sticky side up. Narrower masking tape was used on the edges to attach the tape to the work surface. The seven panels were stuck onto the tape in a row, with a 3/8-inch gap between each panel. Using 320-grit

    sandpaper, I sanded over the panels in all directions. This quickly and effectively rounded the edges of each panel. I then sanded with 400 and 600-grit paper to remove any scratches. The panels were then bent over a square edge in the center to give them a centerline.

    The caboose running boards were removed, and the cabooses were completely disassembled. The roof and floor snap into place on the sides. The interior is screwed to the underframe/floor. When the cabooses were apart, I attached the completed panels to the caboose roofs with styrene solvent. The hole for the smoke stack was opened with a drill, as were the holes for the stack supports. 

    For the CA-5 and CA-6 models, the same procedure was used. I cut the StanRay panels from .015-inch styrene as shown in Figure 2. The corners and edges were rounded using the same technique. The pairs of StanRay panels were attached to the roof, along with the Murphy panels on each side of the cupola.

    Underframe Detailing

    The work on the underframe began by removing the trucks, the coupler arms and springs, and the trainline and brake system. The steps and platforms snap in place and were also removed. To mount Kadee number 78 scale couplers with the scale draft gearbox, a number 55 hole was drilled .060 inch from the end of the metal chassis. The eyelet on the end of the Kadee number 78 box was cut off, and the Kadee box and coupler were attached to the metal floor with the Kadee screw. The screw was cut off level with the top of the metal chassis after it was installed.

    A centersill was cut from .125 x .188-inch strip styrene to fit between the coupler boxes. Two 9/64-inch holes were drilled in the sill for the truck-mounting bolsters cast into the floor. Slots were filed in the styrene sill to clear the cross braces cast into the floor and the trainline. A .040-inch-thick space was attached to the sill on each side of the bolster holes to keep the sill from sagging into the coupler arm depression cast into the caboose chassis. The completed sill was pressed over the bolsters, and the brake equipment was reinstalled. The new centersill was painted black.

    A more accurate sill could be constructed from two Evergreen 1/8-inch styrene channels with spacers between them. In addition, complete brake rigging could be installed using parts from a Details Associates or Tichy AB brake kit.

    CA-3 and CA-4 Detailing

    A photograph of the prototype for the caboose that Marklin chose was included in the referenced book, taken in 1957. Using this photo, I was able to select the correct details for my model. UP 3771 had been repainted in the post-l952 scheme, with the line above “UNION PACIFIC” and below the number removed. UP had replaced the “Q” trucks on 3771 with GSC inside-swing-hanger trucks. Also, the electric marker light was not present at this date. Using isopropyl alcohol and a stiff brush, I removed the lines.

    No plastic models of the GSC inside­swing-hanger trucks have been made, but a close model can be made from the Athearn express reefer trucks. I cut the brake shoes off the trucks and filed the ends where they’d been removed. I also cut off the protruding leaf springs. The resulting truck is very close in appearance to the GSC truck and fits directly onto the caboose.

    The electric marker lights were cut off the cupola. The clear lenses were cut free from the glazing and glued into the housing holes. The holes were then filled with putty and sanded smooth. The trust plates molded into the sides of the caboose body were removed as appropriate. In general, a caboose over 15 years old would have had its plates removed. The steps and platforms were reinstalled to the chassis.

    I also built a model of a pool service CA-4. On this caboose I installed a pair of Centralia Car Shops GSC outside swing hanger trucks with roller bearings. The electric marker lights were retained on the cupola. The trust plate was removed. Overland Models had produced a brass detail part for the generator, but I was not able to find any, so I left this detail off.

    To match the paint that Marklin used, I used Accu-Paint Armour Yellow. This paint is an exact match for that used by Marklin. The entire roof was repainted with Floquil Oxide Red. The pool service caboose was lettered with the post-1972 paint scheme decals and a safety slogan was applied.

    CA-5 Detailing

    The details that were unique to the class CA-5 included the Transco running boards and the outside-swing-hanger trucks. The prototype Transco running boards are made of expanded steel welded to a frame. The expanded steel has a diamond pattern. Plano Products makes two sets of Transco running boards, set 199 and 207. I used one of each due to availability. The running boards were cut to length so that they extended from the cupola and overhung the roof end by .17 inch. The ladder platform was cut down to size so that it extended from the first roof panel joint to the end of the roof in one direction, and from the running board to just beyond the ladder in the other direction. The triangular running board supports were made from.015-inch styrene as shown in Figure 3. A number 56 hole was drilled in each. The supports were attached to the roof end with solvent. The metal running boards were attached to the roof and the supports with Cyanopoxy.

    The CA-5 outside-swing-hanger trucks were delivered with solid bearings (friction bearings). The Centralia Car Shops trucks have the later roller bearings, but were modified to add solid bearings. The roller bearing journal faces were cut off the side frames. Solid bearing journal boxes were cut off a pair of extra freight side frames, Intermountain in this instance. The solid bearing journals were then attached to the side frames with Cyanopoxy. Cyanopoxy is a new adhesive that is capable of reliably gluing all engineering plastics.

    The first 50 CA-5 (25200-25249) cabooses were delivered with wood platforms and steps. The last 50 (25250-25299) were delivered with rectangular pattern steel platforms and steps. I used the etched steps from a Plano running board set for the Centralia Car Shops CA-3/4 (Plano #451) and overlaid them onto my CA-5 platforms and steps. The step treads required trimming. The platform part was undersized but was used anyway. More ambitious modelers can cut the platforms out of Plano’s Apex pattern scratchbuilding material.

    The most difficult part of kit converting a CA-5 and up caboose from the Marklin model is scratchbuilding the end handrails and ladders. For strength and ease of construction, I chose to build nine primarily from brass shapes, wire and detail parts. Brass wire and styrene parts could also be used. I began by cutting 1/16-inch brass I-beam material.

    1.17 inches long for the end beam. Two comer posts were cut from 1/32-inch brass angle, l .06 inches long. These were soldered to the end beam. The handbrake stand uprights were also cut from 1/32- inch brass angle, .54 inch long. A Precision Scale power handbrake was soldered to the uprights, with the flat sides of the handbrake on the uprights. The uprights were then bent to offset the face of the handbrake box back so that the handbrake wheel did not protrude into the platform area. The end beam was filed to fit the handbrake uprights into it, and the handbrake assembly was soldered to the end beam.

    The upright brace from the handbrake to the roof was cut from 1/32-inch brass bar, .7 inch long. It was soldered to the handbrake assembly and bent so that it would meet the roof. The end was twisted 90 degrees to fit flat against the roof end. The horizontal bars were made using .015-inch brass wire. Long pieces of the wire were laid in position and soldered to the comer post and then cut off. This made it much easier to hold the wire in position for soldering. I left the wires extra long on the ladder side, to be trimmed later. On the handbrake side, the bars were soldered to the handbrake assembly. The gate frame was bent from .010 x .030-inch brass bar to be .24 x .50-inch in outside dimensions. Horizontal bars were added to the center of the gate using .015-inch wire and soldered. The completed gate was soldered to the end beam.

    I used some extra reefer end ladders from styrene kits and glued them to the end beam with CA. The horizontal bars on the ladder side were trimmed to meet the ladder. The safety cage at the top of the ladder was built from .015-inch wire and soldered together. It was attached with CA after the end was painted and installed on the caboose. Finally, the brake wheel was glued to the handbrake assembly with CA. The completed ends were painted red prior to installation. 

    I decorated one CA-5 as it would appear in 1959 after it received a five­digit number. The electric marker lights on the cupola and the trust plate were removed as previously described. The line above UNION PACIFIC was removed, and the road number was removed. The paint was touched up, the roof painted Oxide Red, and the car was numbered with Microscale decals. The second CA-5 was built as a pool service caboose. The electric marker was retained, roller bearing trucks installed, and a post-1975 slogan was applied.

    CA-6 Detailing

    The CA-6 class was delivered with inside-swing-hanger trucks. Athearn express reefer trucks were modified as previously described for the CA-4. The CA-6 class returned to the use of Apex running boards, so the Marklin parts were used here. All CA-6 cabooses had steel platforms and step treads, so etched platform and step treads were applied to the ends as with the CA-5. 

    The end railings and ladders on the CA-6 are identical to the CA-5, so they were constructed at the same time. These were painted and installed along with the roof. The electric marker light was removed, along with the trust plate. The prototype for my caboose has a non­standard smokestack brace. The brace was modeled by drilling a pair of holes in the cupola. The Marklin brace was inserted into these holes. I decorated this CA-6 as it would appear in the late 1970s, and the appropriate post-1975 slogan was applied.

    The cut levers were added to all the cabooses. The electric marker lights were made much more realistic by gluing MV lenses in the housing. The Marklin glazing was installed, and the cabooses were assembled.

    Kit-converting and upgrading these cabooses was a great modeling project. Each caboose built was a bit unique, and prototypes were specifically selected to have some of my favorite safety slogans. Although the eras are not consistent in the collection, each is a fun model to build and run behind an appropriate train, bringing up the rear from a time that has slipped past.           


    Article Details

    • Original Author Steve Orth
    • Source Railmodel Journal
    • Publication Date November 2003

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