USAT Intermodal Car Lowered & Kadee 907 Centerset Couplers

USA Trains Intermodal Container Car - Lowered & Fitted with Body Mount Kadee 907 Centerset Couplers

Ted Doskaris

February 23, 2013

Rev GE-A  Initial Release

September 19, 2019
Rev GE-B  Added linkable table of contents; added info. & illustrations for Intermodal unit sets and walkway fasteners; added Videos








Lowering the USA Trains (USAT) Intermodal Container car will allow Kadee centerset type couplers to be body mounted in an aesthetically pleasing, prototypical fashion. By doing this the car will, also, operate better in long, heavy trains - particularly when compared to truck mount couplers.

Currently, I have four "stand alone" type USAT Intermodal Container cars. Three of the cars were purchased from Greg E. Those cars were equipped with truck mounted Kadee 792 offset couplers. The fourth car I had purchased new (a Southern Pacific car).


USA Trains, also, offers Intermodal cars in unit uets of 5 total cars - albeit without containers. It would seem a 3 car set would be a more convenient offering if pressed for space and reduced cost.


Because I currently only have stand alone cars, this vignette (article) does not describe how to lower unit set cars.


It seems the container size length included with a car can vary. (See USA Trains "Intermodal Container Matrix" for various names & sizes)

The SP car previously shown has two "40 foot" containers. Some cars have 45 & 48 foot ones or a combination of sizes.



These cars may have dislodged parts that include the perforated walk plates and the beam that spans between the stanchion uprights.  The walk plates are secured with pins that can fall out and get lost.  I used a shortened garment pin having  a similar size head as a replacement.

Because a substitute pin may fit too loosely due to a its small diameter, glue applied sparingly on its shank can be used to retain it.


As to the beam that connects the stanchions, it can be CA glued in place.  Also, check and repair as needed the ends of the car to make sure they are completely flush at the seams where joining the belly section.


Some time ago before I decided to use Kadee couplers, I had truck mounted Aristo-Craft Knuckle couplers on a couple of the cars.

The following information includes a description with pictures summarizing these different coupler arrangements, including using the relatively new Kadee 907 centerset couplers:

Shown below is the USAT Intermodal Container Car after lowering it with Kadee 907 centerset couplers installed.

Note how the end sill detail appearance is minimally impacted compared to some prior art methods.

The lowered cars with Kadee 907 coupler boxes having been modified to best preserve end sill detail can operate on track curves down to 8 foot diameter - shown below.


With the sampling of four USAT Intermodal Container cars to be lowered, I determined they can be lowered 0.087 to 0.090 inch without having to resort to extraordinary efforts. Accordingly, I have adopted 0.090 inch.

It's to be appreciated that all 4 of these cars have noticeable upward warp at their ends (as other folks who have such cars can attest to) and this is one factor that influences how much a car can be lowered.

Though it's possible to lower an Intermodal car an additional amount to make it even more prototypical, installation complications will arise since one would have to trim off the Kadee 907 coupler box housing rails and do away with the lid so that the centerset coupler will still align with the Kadee coupler to railhead track gauge.

To wit, if one were to lower the car more than 0.090 inch, you would have to use more prototypical wheels (e.g. wheels offered by Gary Raymond) that may offer a reduced tread diameter and / or shallower flanges. This would allow the truck to pivot with needed clearance with a more lowered car, but doing this may not be easily embraced by most folks. I chose to compromise with best effort/ benefit /cost tradeoff and make the most of what comes with the car from the USAT factory.


The first thing checked on these cars is how the coupler pad relates to the Kadee 980 coupler height to track gauge.

According to the gauge, the car as it comes from the USAT factory appears to sit almost 0.10 inch too high!

With the car sitting high, this is a clue to take a look at some prototype information to examine the car height before proceeding.


Examination of the above pictures shows that the Gunderson "Husky Stack" non "All Purpose" (non AP) type car closely resembles the USAT Intermodal car. Note how close the prototype car belly is to the rail head. The belly appears to be lower than the roller bearings in the trucks!

Moreover, the dimensional drawing, though not too clear, shows a height spec. of 7 foot 9 inches (7.75 ft) as measured from the top of the brake wheel to the railhead. At 1/29 scale, this car height is 7.75ft / 29 = 0.2672 ft. Or 0.2672 ft x 12 inch/ft = 3.21 inch.


Shown below is the USAT Intermodal car as I measured it.

Measuring the USAT Intermodal car shows it sits about 3.7 inches above the rail head. That's almost 1/2 inch difference compared to the prototype; however, one thing that is not known is the size of the brake wheel diameter on the prototype car vs. the one USAT chose to use on their car. Also, the ends of the car are warped uphill - so these can make some differences. That said, the thing to conclude from this info. is that the car can be lowered somewhat and appear to be made more prototypical.


It's best to use the emulated roller bearing truck that comes with the car.

The truck used on the Intermodal car has a relatively short wheel base which is helpful for the Intermodal car since it keeps wheel flanges closer in from the end sill. With a wheel base measuring 2.25 inches it is shorter than the that of the USAT metal roller bearing truck used on the tank cars, etc. and shorter than the metal AML roller bearing truck used on their PS 2 hopper, etc. car, and shorter than Aristo-Craft's plastic Barber roller bearing truck. So attempting to fit any of these as alternatives would seem to make matters worse.

Given a reasonable wheel tread diameter but with the constraints of having tall flange heights of the trucks used on the USAT car, I concluded that the car can be lowered 0.090 inch. This allows the coupler pad to be located at about the proper height with the truck still being able to pivot (with some minor mods. to the car) whilst, also, making the car appear to be more prototypical as to belly distance from the rail head.

Shown below is what the overall car looks like (retaining the factory truck and wheels) but having been lowered with Kadee 907 body mount couplers.

In order to least impact the appearance of the end sill detail of the car, and still have workable car operation in a train, I chose to use Kadee 907 centerset coupler assemblies. However, modifications to the coupler box and lid must be done along with some cutting on the end sill of the car.


Shown below is a drawing of the modifications required of the coupler box and lid.

Shown below are the actual modifications done to the Kadee 907 coupler box and lid and how the whole assembly is to be placed on the car's coupler pad.


Shown below is an example method for removing the required material from the bolster wings.

In the event too much material was mistakenly removed from a bolster wing, a shim of appropriate size can be CA glued on the bolster wing. An example using a piece cut from brass sheet is shown below; however, the shim thickness chosen will depend on the actual amount that must be used. (Before gluing a metal shim, be sure to clean its surface with alcohol so the glue will have best chance to bond the shim to the plastic bolster wing.)



Shown below summarizes what must be done to modify the car to lower it and to accept the coupler assembly.

Shown below is a method for cutting the "U" slot in the end sill for accepting the modified coupler box.

Shown below is a method for trimming the inboard side of the end sill that is required for the mounted truck to pivot so its wheel flanges don't interfere when the car is operated on curve track.

In order for the car to operate on 8 foot diameter track curves, the sides of the coupler box must be beveled so the truck can pivot a bit more. This was shown in the coupler box drawing. (Note that this is not needed if your layout has 10 foot or greater diameter track curves.)

When re-installing the truck, install the truck first, then place a few 1/4 inch ID washers over the protruding pivot post before putting the screw to hold the truck in place. The truck should still freely pivot, but this keeps it from wobbling.

With all modifications done, the coupler can be made to align with the Kadee 980 gauge. In this regard, some minor shimming at one end or the other of the coupler box may be needed to best align the coupler because the ends of the cars that are typically warped uphill may be inconsistent.

With all modifications done, the coupler aligns with the Kadee 980 gauge.


Shown below is the example ATSF car with trucks mounted after having all modifications done to the car. Note the location where the bubble level is placed across the car body for an accurate indication.

Shown below is the example DTTX car with trucks mounted after having all modifications done to the car.

The bubble shown in the level placed across the car body should match the bubble in the level placed across the track railheads. If notably off, the car bolster wings need to be examined for consistency with respect to how they were cut. Trimming down one side of the wing on one end of the car (or shimming up a wing) may need to be done to correct a leaning car. Likewise if the car exhibits notable side to side wobble.


The wheel back to back spacing should be checked and adjusted - particularly important for operation on 8 foot diameter track curves.

Also, lateral axle movement can be minimized to help reduce drag when the car is operated on curve tracks - though doing so for operation tight 8 - 10 foot diameter curves may be counterproductive for this particular car type.

The USAT wheels appear to be black painted over brass metal. The paint should be cleaned off the tread surface so it does not deposit on the rail heads when the car is operated on the layout track work. This is particularly important for track powered layouts to prevent insulating debris forming on the rails.

When reassembling the axles in the truck, the tips should be lubricated.


USAT produces containers in different size lengths. The ones I have are replicas of 40 foot, 45 foot, and 48 foot. The car body has recess provisions to accept these size containers as well as a couple of 20 foot containers.

To keep the containers in place during car operation on a layout, USAT provides some plastic locating pegs, P/N "R17PN - CONTAINER PINS- SET OF 8".


Depending on tolerances and where he pegs are placed in the container, they can be loose and easily misplaced unless glued in place.


Shown below is the Intermodal car with stacked containers along with measured weight .


Adding weight may be necessary for car operation when placed at the front of long, heavy trains - particularly for operation on curves - important when only using one container without having the benefit of a stacked container's weight or when not added extra weight.

First some measured weights of the car and containers by themselves.

Since a container has a recess of about 1/ 4 inch deep on its underside, a steel plate of about that thickness can be placed in the car well with the container put on top of it without noticing the weight. I chose a 1 1/2 inch wide, 1/4 inch thick plate sold in 3 and 4 foot lengths at an Orchard Supply Hardware (OSH) store and cut it into 15 5/8 inch sections.

Alternatively, weights can be put inside the container that would be placed in the car well - not the stacked container. To do so, the container's doors can be open and closed using care not to force the delicate plastic mechanisms.



Shown below are two USAT Intermodal cars equipped with Kadee 907s with the all modifications on 8 foot diameter track curves.

Shown below is the end sill separation distance of the two cars when placed on a straight track.

Shown below is an over head view of the car being uncoupled over a Kadee magnet.

Shown below is a modified USAT Intermodal car by itself on the under house layout 10 foot diameter loop back over an Aristo Wide Radius turnout.

Shown below is the under house layout with two modified USAT Intermodal cars coupled to the trailing unit of four Aristo GP40s in a long train on 10 foot diameter curve track of the 270 degree loop back.

Shown is the top view of the car coupled to the loco.

Shown below is a side view from inside the 10 foot diameter track loop.

Shown below is a side view from outside the 10 foot diameter track loop.



The videos to follow mostly describe 3-D printed "CamPac BoxesTM" fitted with Kadee centerset (no offset) couplers that are installed on the locos and some of the cars.

I can operate double stacked containers on the Intermodal cars on my outdoor layout, but the cars are limited to one container when operated on my underhouse layout because of height clearances.

That said, operation of a train having all Kadee body mount centerset couplers is shown that includes the stand alone type USA Trains Container cars that are lowered with body mounted Kadee couplers.


Operation of that train is shown returning to my underhouse layout that includes the stand alone type USA Trains Container cars.




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