The East Penn Traction Club
Introduction to Trolley Modeling - Glossary
Anticlimber: A metal casting or forging on each end of a car's frame. Horizontal ridges reduce the tendency of one car to ride up over another car in a wreck, to minimize loss of life.
Arch Roof: A car roof with a curved shape, lacking a clerestory. Most featured ventilators to exhaust heat from within the car.
Birney: A lightweight trolley design developed by Charles Birney, featuring special safety features. Usually four-wheeled, but not all four-wheel trolleys are Birneys.
Box cab: An electric freight locomotive with a boxy cab for the operator and electrical equipment. No freight is carried in the carbody.
Box motor: A powered car with operator controls at one or both ends, with space for carrying freight. May operate alone or may pull one or more freight cars.
Box trailer: An unpowered car for carrying freight. Similar to a railroad boxcar, but with rounded ends to accommodate sharp curves. Some were built for the purpose; others were converted from old passenger cars.
Clerestory: A raised portion down the middle of a car's roof to provide light and ventilation. If the clerestory's ends are squared off, it's called a deck roof; if the ends curve down to meet the end of the carbody, it's called a railroad roof.
Combine: A car, usually interurban, with space for both passengers and freight or express. A few combines also had Railway Post Office sections.
Controller: A large electrical device with a rotating handle, used by a car's operator to control acceleration. Functional equivalent of an automobile's gas pedal. Usually mounted next to the air brake valve.
Convertible car: An early streetcar design which allowed the side panels to be removed and stored when warm weather arrived, eliminating the need to keep a separate fleet of open cars.
Double-ended car: A car with controls and trolley poles at both ends for bidirectional operation. Compare with a single-ended car, with controls at only one end and just one trolley pole, which must be turned on a loop or a wye track. Some double-ended light rail vehicles have only a single pantograph, which can be used in either direction.
Interurban (vs. Country Trolley): Interurban railroads traveled from city to city, generally leaving public streets at the edge of town for private right-of-way, which might parallel a highway or railroad line. Cars were comparatively heavy and fast. Country trolley lines were lighter in construction, often running on the shoulder of the road outside towns. Cars were smaller and slower. Some lines were a little of each.
Line pole: A pole along the track that helps support the overhead power wires.
Loop: A sharply-curved track at the end of the line that allows cars to turn and head back the way they came. Essential for operation of single-end cars; a convenience for operation of double-ended cars.
Multiple-unit: A form of electrical control allowing an operator in the lead car of a train to control the motors of all cars in the train. Applies only to the prototype; not necessary for model operation.
Open car: An early streetcar design with the sides open to the weather; popular during summer when people would escape sweltering homes to ride the "breezers". Cars were stored during cold weather, requiring a company to maintain two fleets of cars.
Pantograph: A heavy-duty overhead current collection device. Early versions were diamond-shaped; newer pantographs resemble a forward-facing letter "V". Usually operated with catenary overhead.
PCC Car: A streamlined, lightweight streetcar developed by the Electric Railways Presidents Conference Committee in the 1930s. Thousands were built, with many variations covered by the PCC patents.
Power truck: A model car truck (the wheel-axle-bolster structure on which the carbody rests) with an electric motor geared to one or more axles. On double truck models, the second truck is usually unpowered.
Retriever: A round, spring-loaded device on the carbody below the trolley pole, connected to the end of the pole by a rope. If the shoe or wheel comes off the wire, the spring will pull the pole back down to minimize damage to pole or overhead wire.
Span wire: In direct suspension overhead, a wire strung between two line poles, which which the contact wire is suspended.
Special work: Switches, crossings and related trackwork custom-built for crowded locations, such as carbarns and yards.
Steeplecab: An electric freight locomotive with its cab in the middle of the carbody, and hoods for electric gear sloping down toward the ends.
Substation: On prototype lines, electrical equipment which stepped down high-voltage alternating-current power feeds to safer operating voltages, and on most lines converted it to direct current. Typically located 6 - 12 miles apart.
Third-rail shoe: An electrical current pickup device mounted on the sideframe of a truck to contact the third rail running next to the track. Used on most rapid transit and many suburban lines. Right-of-way was fenced to protect the public.
Trolley pole: The most common overhead current collection device. The base has springs to press the pole upward against the trolley wire. Contact is made via a brass wheel, which looks like a pulley, or via a sliding shoe.
