T — Z
Truck. A foreshortened form of the older, but more proper, term “car-truck,” denoting the wheeled apparatus supporting an 8-wheeled railway car. In some parts of the world perhaps more properly called a “bogie.” The small four-, six-, or sometimes even eight-wheeled car under each end of a typical North American railway car body that supports it and carries it down the track. Its purpose is to enable short wheel-bases to be used in connection with long car-bodies.
Truck bolster. A cross piece, for many years made of timber, holding together the truck side-frames, and supporting the car body on the truck center-plate which is attached to its center. The truck bolster is connected to the body bolster by the center-pin about which the truck swivels.
Truck center-plate. One of a pair of plates, originally made of cast iron, that support a car body on the center of its trucks. The center-pin passes through them but carries none of the strain except in emergencies, due to the male and female shape of the corresponding plates.
Two-and-one seating. (below) The early narrow gauge cars were too narrow to have two double seats with a reasonable aisle, so they generally had a double seat on one side of the aisle and a single seat on the other. To keep the car “balanced,” this was reversed at the middle of the car, so that the double-seat side became the single-seat side. Here’s the interior of an early Barney & Smith car showing two-and-one seating: