AML reefers with Kadees and AML coupler boxes

AML Wood Side Reefer Fitted with Kadee 900 Couplers In AML Boxes
Ted Doskaris
May 31, 2011
Rev GE-A

The American Main Line (AML) model is of the prototype PFE Western Pacific wood side refrigerator car built around 1923 / 24, but it  appears to represent a "reconditioned" variation (circa 1939) in that the brake wheel is re-positioned from the top to the bulkhead side.  Also, the trucks resemble those used on the recondition prototype car.  (Prototype Southern Pacific / Union Pacific PFE cars were similarly reconditioned.)

Reference book:  "Pacific Fruit Express", Second Edition, by Anthony W. Thompson, etc., Published by Signature Press, ISBN1-930013-03-05

I fitted two new PFE WP refer cars with Kadee 900 body mount couplers using the AML coupler boxes provided in the boxes with the cars.

First, About the Coupler Boxes & Couplers:

The AML coupler boxes can be adapted to accept Kadee couplers. Both the Kadee 830 and newer Kadee 900 AAR "E" generation couplers can be made to fit into the slightly smaller AML coupler boxes.

Shown below is a comparison of Kadee 830 and AML assemblies.

Note the AML coupler has an offset with respect to its shank, whereas, the Kadee coupler is centerset.

The Kadee coupler has a slightly thicker shank than the AML coupler. In order to fit it into the AML box so that it correctly pivots and does not bind when the lid is fastened, the pivot post being too short in height and too small in diameter must have a sleeve placed over it. 

A small thin washer of 0.012 inch thick can be placed on top of the pivot post to gain the little extra height needed to allow the Kadee coupler free movement; however, I found that using the washer was not really needed provided the sleeve itself is made about 0.012 inch taller than the post.

Also, the surrounding 3 sides of the box can be built up using duct tape being placed on the box lid periphery.

Placing 2 or 3 layers of duct tape around the periphery of the box lid serves to build up the sides of the AML coupler box.   Where the tape comes close to the opening, it should be tapered so that a swinging coupler shank won't come in contact and stick to it.

As an alternative to the nylon sleeve, the plastic part of an electrical crimp (blue color) is just about right to improvise a sleeve from.

 Shown below is the improvised sleeve from an electrical crimp installed over the pivot post.

Shown below is the AML box assembled with a Kadee 900 coupler installed.

Because the AML box with the Kadee coupler installed is now slightly thicker than intended with the AML coupler, longer mounting screws are needed. I used no. 2 by 5/8 inch long screws in place of the shorter AML supplied screws.

Mounting Issues:

When first attempting to mount the  coupler box assembly fitted with  the Kadee coupler onto the floor pad, I noticed that the coupler did not align with the Kadee 980 gauge used to determine proper coupler height to rail head distance.  It was too low!

 It appears AML optimized its floor pad so as to favor  the use of its own couplers, which have an upward offset coupler to shank relationship - unlike the Kadee centerset coupler. This can be seen in the below picture.

Notable, too, was that one car had a pronounced warp to its floor on one end.  I removed the floor to check it. This is likely due to the molding process when made at the factory.

The floor is held in place by 8 small screws that insert into 8 tube like posts (4 each side).

Since the floor attachment points are rather distant at about 1 1/2 inch from the ends (no fastener at the ends) , the more or less  warped ends seem inconsistent as to their attitude when installed in the car.

As a solution,  I used a large "C" clamp to depress the floor end further into the car body (noticeably deeper from being level)  and drilled a hole in the end of the car so as to secure the floor.
The hole should be centered across the end of the car's bulkhead and located about 0.150 inch down from the edge - just enough to clear the uncoupling rod detail when using one of AML's left over black mounting screws.

A smaller pilot hole can be first drilled through both end bulkhead and the floor whilst held by the clamp; then a larger hole the size of the screw body is drilled only part way through (end bulkhead only).

With the floor still held in place with the "C" clamp, the screw is to be threaded in.

Shown below, the installed floor retaining screw can be seen when looking through the top of the car's ice hatch.

With the "C" Clamp removed and screw installed, the floor end is intentionally to favor a deeper attitude - opposite to that of the way it was. 

Surprisingly, this allowed for the installed  AML coupler box assembly with the centerset Kadee coupler to properly align with the Kadee gauge.

The view below shows the floor end retaining screw head adjacent to the uncoupling rod. The screw used was meant for the AML coupler box mounting. Since the box with the Kadee coupler needed longer screws to mount it, The left over screws were good to use since they are black finished.

The view below shows the mounted coupler box assembly on the underside of the car.

The mounted coupler box striker plate end projects about 1/4 inch from the bulkhead sill.

Looking at  book,  "Pacific Fruit Express", Second Edition, by Anthony W. Thompson, etc., Published by Signature Press, ISBN1-930013-03-05, page 92 shows a drawing of a similar wood side reefer.
The drawing shows the striker is dimensioned at 5 7/16 inch from the bulkhead sill. Scaling this down to 1/29th results in 0.1875 inch - which means the AML car coupler box projects about 33 percent more than the prototype.  Appearance wise, probably not enough to be concerned with except for most discriminating modeler - in which case the box could be remounted, accordingly - albeit requiring some ingenuity.

The extra projection provides for more than enough clearance between coupled like kind cars when on 8 foot diameter track curves as shown below.

Operation on the Layout:

The two AML brand PFE Western Pacific reefer cars with Kadees were coupled at the head end of a train totaling 61 cars.

The following pictures illustrate the coupler attitudes on the 10 foot diameter, 270 degree loop back  of the layout:

The pictures below show the two reefer cars coupled together on the 270 degree loop back.

The tape used between  the AML coupler box and lid to help accommodate the Kadee coupler can be seen in above and below pictures.  A black marker pen helps to disguise the edge of the tape.

The AML cars fitted with AML coupler boxes adapted to accept Kadee 900 type centerset couplers performed very well  and without incident when operated on the layout.

If stock cars are on a train, it's more prototypical to place the stock cars directly behind the locos, then the other cars. This appears to have been done to avoid injury to livestock by keeping  cumulative coupler slack takeout to a minimum.

Observations about the AML PFE Wood Side Reefer Car:

The AML reefer car  is fairly heavy for its size measuring about 3 pounds.

Illustrated below is the relationship of the truck and the AML coupler box assembly adapted with Kadee 900 centerset coupler.

The trucks, particular the wheel quality, on these cars are much improve compared to prior AML offerings such as on the box cars and stock car types.

The trucks are equipped with actual springs, and the wheels roll much better with smooth wheel treads. (The prior cars felt like their wheels were rolling through a bunch of rocks!)
The lateral play of the axles are much improved, too. (The prior cars were excessive to the extent of inviting undue wheel skew (angle of attack) with resultant operational drag on curve track.)

The trucks are mounted like those on the prior stock car versions, but with a much firmer spring tension; therefore the wobbling and leaning of the car on curve track has been eliminated.

The wheels appear to be made of a ferrous material being a magnet has strong attraction to them - and axles, too.

Trucks that look like the AML ones were used on the prototype PFE WP wood side reefer car,  of which is shown in the PFE book (previously cited) on page 107.  (Likewise for the PFE SP / UP car shown on page 135.)
However, the wheelbase of the truck measures 2.40 inches as shown below.

At 1/29th scale, this wheel base scales up to 5.8 feet, (5 feet, 9.6 inches!).  Trucks with a long wheel base of 5 foot 8 inches were used, but not too common. (5 foot, 6 inch is the more common wheel base, such as shown in the PFE book on page 120.)
That said, in the PFE book on pages 122 and 123, a PFE wood side reefer car (albeit a 52.5 foot size car with dreadnought ends) having trucks that resemble the AML model is shown with 5 foot, 8 inch wheel base trucks.

All-in-all, the 1/29 th scale AML wood side refrigerator car is a high quality, well crafted model and noticeably improved from prior car offerings - like its close relative, the stock car.
I do, however, suggest AML improve this car (and other cars) by fastening  the floor ends at the car's end bulkheads so as to be level and changing the coupler mounting pad height to accept Kadee 830 / 906 assemblies.
 It is easier to add shims (if need be) than to remove material from the surface of the floor pad area.



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