They were single-ended, low-floor cars designed for operation by a single man and were built largely of aluminum to save weight and, therefore, require less power to operate. The biggest difference from the C&LE cars was in the trucks: whereas the C&LE cars had smaller arch-bar trucks, the IR cars were designed with heavy Commonwealth cast steel trucks designed specifically for high-speed service and to cope with poor light rail track.
Single-ended, low-floor vehicles designed for single operation by a person, built primarily of aluminum to reduce weight and thus decrease power requirements for operation. The primary distinction from the C&LE cars was in the trucks: whereas the C&LE cars had smaller arch-bar trucks, the IR cars were constructed with heavy Commonwealth cast steel trucks specifically designed for high-speed service and to handle poor track conditions.