Built by General Steel Castings starting in February of 1952, these steel, easy-riding caboose trucks first appeared on 50 of UP's class CA-3 & class CA-4 riveted steel cabooses, replacing the older wood framed "Q" trucks they were originally equipped with. Seven months later, all of UP's new class CA-5 steel cabooses arrived equipped with these new steel trucks, which railroad personnel called "outside swing hanger" trucks with their distinctive stabilizing torsion bar. The solid-bearing versions of these were original equipment on UP's class CA-5 & CA-7 cabooses, with the roller-bearing version being original equipment on class CA-8, class CA-9 and class CA-10 welded steel cabooses. Early solid-bearing versions had their original bearings replaced in many cases, with the journal covers painted Armour Yellow or Aluminum to indicate to yard maintenance crew that no waste-oil wadding was needed. By 1958, all of UP's steel center cupola cabooses had been converted to roller bearing trucks, either by conversion or with new original equipment.
Older releases of the Golden West Models / Centralia Car Shops / Intermountain line of UP CA-3/CA-4 caboose kits included General Steel Castings outside swing hanger trucks (although not anymore). Said trucks were multi-part assemblies that were somewhat prone to falling apart. The original GWM trucks appear to have roller bearings, whereas the revised trucks on the CCS/IMRC cars have trucks representing the original solid bearing outside swing hanger trucks first introduced in 1952 with journal box lids.
Golden West Models -
Centralia / Intermountain -
