encyclopedia

RADIAL SERVICE

Local or express service designed primarily to connect the Central Business District with outlying areas. Also called a pulse system.

RADIO CONTROL HEAD

The controlling device, rectangular in shape, equiped with channel selector, TX light, volume control and SAS. light.

RADIO HANDSET

A device similar in appearance to a telephone, equiped with a push to talk (PTT) button which must be pressed to transmit.

RADIO-CONTROLLED ENGINE (SLAVE UNIT)

In passenger trains, an unmanned propulsive unit within a train that is separated by rail cars from the lead unit but controlled from it by radio signals. (TRB)

RADIUS OF CURVATURE

A rating of the severity of a curve by comparing it to an arc of a circle of stated radius. (TRB)