USAT 4 Bay Hopper & Kadee 830 couplers


USA Trains Golden West Service 4 Bay Hopper Car & Kadee 830s
January 10, 2010
Ted Doskaris
REV. GE-B - added pictures of additional road numbered cars

revised 2016.7.3, fixed broken link to Lee Geautraeux's SP pictures

USA Trains makes a well crafted 4 bay hopper car in the Golden West Service (GWS) livery, no. R141001. Significant use of metal is employed in the car making it fairly heavy at almost 5 lbs.
The car's length is about 25 inches - standard USAT truck mount knuckle couplers included.

The GWS car is a special production run car. I purchased one from RLD Hobbies located in Albion, Ill. I followed up with an order for 3 more as there are 4 road numbers offered.

Shown below in the plastic bags are the USAT supplied Kadee "adapter plate" (spacer) and reformed coupler lift bar (uncoupling rods) used to go around the Kadee coupler box.

The car's reporting marks are for S.S.W. (Cotton Belt).
GWS appears to have been a Southern Pacific RR entity borne out of financial creativeness.

A little prototype information with pictures - albeit 3 bay car versions - can be found at Lee A. Gautreaux's web site

Shown below is USAT's replica of the car.

The box that the car came in did not indicate USAT's number, R141001 !

Views of the car fresh out of the box are shown below:

The car is a high quality, detailed product that includes many metal parts.

The roof walks on the top of the car are metal.

The truck's bolsters, side frames and even the standard USAT truck mount knuckle coupler is metal. The "B" end of the car is shown below:

The "A" end of the car is shown below:

Shipping Damage & Repair

As I have found with other USAT detailed products, there seems to be a propensity for shipping inflected damage. The car I received had two items amiss:

Shown below is a dislodged part hanging from its chain.

A little CA glue took care of the dangling part that otherwise would not stay put. Looking around the car, I found another like kind part about come off so I glued it, too.

Shown below are the holes for a missing pin that is to serve as a pivot for the mechanism having to do with one of the hopper's operateable dumping doors.

The surrounding components are fairly fragile, so care should be used if attempting to operate the doors.

Note how little clearance (about 1/10 inch) there is between the rail head, too.  Having such a tight clearance allows for not much of a crown in the track work for an outdoor layout if cresting a hill.

I could not find the missing pin, so I improvised and used a brad to take the place of the pin. I cut a #20 brad to about a 1/4 inch long and filed its end free of burrs and added a slight taper.

The brad went through the pivot arm hole OK, but I had to ream out the body hole a bit so it would press in (using & twisting its pointed end I had cut off as the ream). Shown below is the installed brad.

The hopper doors can be opened, but part of the mechanism then touches the rail head as shown below.
Care must be taken to ensure the hopper doors are fully closed or else risk the snagging of fragile parts on the slightest amount of protruding track work (e.g. Aristo re- railer ramps that stick up above the rail head.)

Shown below is the underside view of the car with all four of the hopper's horizontal dumping doors opened.

Shown below is the underside view with all the doors closed.

Kadee 830 installation

The trucks and the factory installed wire uncoupling rods (emulated coupler lift bars) must first be removed from the under frame of the car.

Shown below is the factory installed uncoupling rod that is used with truck mounted couplers.
(USAT supplies a replacement that is shaped to clear the mounted Kadee 830 box.)

Heed the USAT instruction sheet for removing the coupler lift bars.

The mostly metal trucks with their metal wheels weigh about 3/4 lb, each!

The coupler and tang assembly arm must be removed. Only one screw holds it in place.

Both the coupler and tang are made of metal. It is removed so as not to interfere with the Kadee 830 box. Later, when the truck is reinstalled, it must be rotated 180 degrees to clear the 830 box.

USAT provides two square spacer boxes painted in the body color of the car intended when installing the Kadee 830s.

Each spacer is held in place with the 4 USAT supplied short length self threading screws.

I found the need to use a Kadee 1/32 inch thick shim on top of the spacer, too, so that the installed coupler on the car would best align with the Kadee 880 coupler height gauge. (This thickness spacer is included in a Kadee 841 Gearbox Shims kit.)

Fasten the Kadee coupler boxes using the USAT supplied longer self threading screws (3 each box); however, if using an additional shim, a longer screw is preferable too insure adequate thread penetration. Substituting a 4-40, 5/8 inch long screw should work depending on the shim's thickness.

Uncoupling rods Installation (emulated coupler lift bars)

These rods provide a degree of realism but do not serve to actually perform any uncoupling.
Kadee couplers can be made to uncouple using a Kadee magnet placed in the track work.

Install the uncoupling rods as supplied by USAT that are formed to fit around the Kadee 830 box.
The rod is first threaded through the little eyelet located near the corner of the car and then the end of it is pressed into the hole on the underside of the car that is located near the Kadee coupler box.

Note: I have found that these rods may interfere with the wheel flanges when the Car is entering and leaving to / from a straight track to a curve track.

I left the rod as is since the wheel flange will find its way past the rod's interfering corner during typical operation.

However, if the car were to be operated on a long, continuous curve section (somewhere between 10 and 20 foot? diameter), the rod should be modified.
Bending the rod should be done with caution as it is hardened metal and prone to cracking - particularly at the factory bent areas.

Trucks, re-installation

The trucks (with removed tangs) are to be reinstalled with them turned around from what they had been so that their stepped end is used to provide clearance above the Kadee box.

The installed truck is limited by how much it can pivot by the Kadee box.

If you try to operate this car on the smaller 8 foot diameter track, its wheels will rub on the side of the Kadee 830 box as can be seen by the swirl marks in the below picture.

The wheel flanges will also bind against the side of the rail head causing undo drag.
Shown below is the car placed on an 8 foot diameter track.

Shown below is an underside view that serves to illustrate how the axles are skewed with the wheel flanges binding against the side of the rail head.

By pushing the car back and forth on an 8 foot diameter curve, telltale marks will appear on the wheels' backsides and 830 box. Turn the car around and do the same thing so both sides are exercised. You can file away some material from the Kadee 830 box where the marks are to help ease the situation. Note that the side mount screws areas of the box are obvious points of contact, but also the wheel's sharp flange edge will leave a slice mark closer to the front of the box that may not be as obvious.

Shown below is the underside of the car with the Kadee 830s and trucks mounted to the car.

Coupler alignment and  measured car length & weight

Shown below is the car with mounted Kadee 830 coupler that aligns with the Kadee 880 coupler height gauge. A Kadee 841 shim of 1/32 inch thick may be necessary for best alignment as I had done with this car.

Shown below is the car coupled to an Aristo Cotton Belt GP40 having retrofitted Kadee couplers.

A close up of the couplers are shown below as a reference.

Shown below is the other end of the car at the coupler area.

The car length measures 24 and 3/8 inch across - extending to the Kadee 830 coupler mouths.

The measured overall weight of the car with the Kadee 830s mounted is about 4.5 lbs.


I coupled the Car directly behind a pair of USAT SD70s pulling a 57 car train. The SD70 has a custom adapted self centering swinging Kadee 787 medium off-set coupler.
(This SD70 coupler modification is described in another article .)

The SD70 represents a worst case application since its front pilot has an excessive amount of projected overhang on curve tracks that results in its coupler being undesirably located when attached to a car. Consequential forces will then tend to pull the car's wheels against the outer rail with the possibility of pulling the car off the track - particularly with long, heavy trains.

Shown below is an overhead view of the Car as coupled to the SD70 loco with the train remaining in tension after coming to a stop. The train operated OK around the 270 degree loop back of 10 foot diameter track where this picture was taken.

Shown below is the side view of the loco and car couplers as viewed from the outside of the 10 foot diameter track curve.

Note the cut area I made with a file in the side of the coupler box can be seen behind the wheel flange.

Shown below is the other side of the loco and car as viewed from the inboard side of the 10 foot diameter curve.

Shown below is an overhead view of the Car all by itself coupled to the SD70 loco located on an 8 foot diameter curve section of track that goes into my rail yard area.

Even though I had provided a degree of relief by filing selected side areas of the Kadee 830 coupler box for added wheel clearance, the car does exhibit noticeable drag on this tight of a curve. (My mainline track curves are 10 foot diameter or greater where the car operated OK with less drag.)
Shown below is another view of the car and loco at the same location of the 8 foot diameter track curve.

Whilst operation on 8 foot diameter curves is tolerable to a limited extent when trimming the Kadee box, the USAT 4 bay hopper car is best operated on 10 foot or greater diameter track.


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