Q) When were friction bearing (solid journal) trucks banned from interchange service?
A) Friction bearing trucks were banned from interchange service on 1/1/91 for cars carrying hazardous materials. All other non-hazardous carrying cars equipped with friction bearings were banned from interchange on 1/1/94. Cars with converted friction to roller bearing side-frames were banned from interchange on 1/1/95.
There were some instances of exemptions granted for shippers in “hardship circumstances” who could not comply with these dates. So, some cars did linger a little longer in interchange after the actual deadline dates.
Q) I understand the logic behind eliminating solid journal (friction) bearings from interchange service, but what was the reason for outlawing trucks with conversion roller bearings?
A) Hot bearing detectors couldn’t “see” them when they overheated.
“Roller-bearing trucks have been around since the turn of the 20th century - began to see common use in the 1930s on passenger cars. - weren’t widely used on freight equipment until the late 1950s and 1960s. - New cars built after 1966 were required to have rollerbearing trucks - solid-bearing trucks were banned from interchange service after 1980.” Found a thread on another Forum that says in a later reprint “1980” changed to “1990”
Several years ago “Trains” ran an atricle about a short-line railroad in Florida that was still using hopper cars with friction bearings. This was an agricultural/industrial 'road that did not interchange with any other railroad at all. The hopper contents went straight from the loading area to the processing area several miles, don’t remember how many, and no further.
Sorry, but I don’t remember the name of the railroad.
If a railroad doesn’t interchange a car, it can run it any way it wants. That includes truss rods, wood beam trucks, no air brakes at all. It’s when it is interchanged that rules start applying.
United States Sugar in Florida still has some equipment with older “friction” trucks. It all operates on private rail. The primary load is bringing sugar cane in from the field to the mills. This might be what you are talking about.
Interesting tidbit I just picked up - truss rods themnselves were never specifically outlawed. It was wood frame cars that were outlawed, and since steel cars don’t need truss rods, they sort of disappeared on their own. This is in Tony Koester’s new book, Modeling the Transition Era.
Between 1922 and 1926, the Southern Railway took delivery of almost 15,000 SU class boxcars. These had truss rods and steel underframes…
Wood-framed cars, including those with steel-girthed centre sills, were banned from interchange on January 1st, 1940. Truss rods were still allowed on composite underframes.
On January 1st, 1952, cars with composite underframes were banned from interchange.
The definition of “composite underframe” is unclear to me - since the wood-framed cars were covered in the 1940 ban, does composite refer to steel-framed cars with truss rods? I can’t see why it should, as it’s unlikely that the steel frame would be negatively affected by the truss rods. The lack of clarity does seem to suggest, though, that truss rods may have been banned from interchange by that latter edict.
The Southern’s SUs began to be scrapped after WWII, but some of them went to the Atlantic & Danville and the Lancaster and Chester. There are photos of the latter two in Ted Culotta’s Steam Era Freight Cars Reference Manual - Vol. 1, both taken in 1952, which makes me wonder if the ban prompted photographers to “get 'em while ya can”.
The Monon had 500 similar cars, built in 1923, and the Mobile & Ohio (under Southern control at the time) had at least 1400 40’ versions of the same car, 500 of which were originally automobile boxcars.
Wood underframes have a structure primarily made of wood.
Composite underframes have a structure that is made of both wood and steel.
Unless someone can turn up some sort of official declaration (ICC, and all that), it’s still pretty open about truss rods, and any declaration against by officialdom.
I would propose that truss rods may have become “inappropriate” for car design, not forbidden. In that case, they disappeared because no one wanted to build cars using them.
Middle axle of each truck retains the converted plain bearing box. All others have normal roller bearings. DODX 39912(-19). And yes they are interchange, considering they have been photographed on P&W, NS and CSX. Im guessing there is some sort of exception for these cars.
Those are actually roller bearing modified journal boxes. These were pretty common in the Sixties. The railroad would remove the journal cover and bore a large hole where the oil well was so water wouldn’t collect in there.
Tough to find an example. Scroll down to fourth from last photo here:
I suspect most restrictions preventing use in interchange service are actually established by the AAR rather than the government, which is why restricted cars can still be used on the owning railroad. The ban is not absolute, but before such a car can go off-line the receiving road has to agree to handle it, and that is unlikely to happen except in very special circumstances.
The last plain bearing car I saw in regular operation was an air-dump on CPR, back in 2012. Others in worktrain use had been converted to roller bearings but somehow this one had escaped. The next year (2013) a pair of CN 40’ boxcars renumbered for OCS service appeared in the local yard, complete with high brake wheel and running boards on the roof (but roller bearings). Quite a blast from the past!
I’m of the opinion that the shop probably removed the non-integral journal boxes and applied the necessary adapters to accept the roller bearing wheelset. The center axle journal box is cast integral with the carrier so was modified (see procedure below).
Here’s a closer view of the trucks under the DODX 39918:
I say “some” because I believe the designs of the truck evolved over the years. In 1944 the Buckeye tender trucks under this particular Berkshire were cast with integral journal boxes and clasp brake assemblies.
You can see the original journal box wall section. The protruding part of the box has been milled off.
Below are instructions for making the conversion yourself, should the need ever arise.