These single-axle roller bearing trucks were specifically designed for TTX's 1984 "Front Runner" spine cars. There were actually two styles of trucks used on these cars, but the UIC (International Union of Railways) type truck was the most common. Based on a European design, it is identified by its large leaf springs above each wheel set. The other truck arrangement (a Uni-Truck II), has coil springs located on either side of the roller bearings. This single-axle design ultimately proved unsuccessful and the cars were scrapped circa 2000.
Atlas's similarly short-lived front runner models were the only use of these trucks in N scale -