The Skoda 14 Tr trolleybus was already under development in the first half of the 1970s, but wasn't put into series production until 1981. During the 1980s and 1990s the trolleybus underwent a series of many design changes. Individual production series differ from each other by partial equipment modifications and units used.
The three-door body with a floor height of 750 mm is welded together from thin-walled closed steel profiles, and the walls and roof are covered by steel sheets with an anti-corrosion coating. The inside walls and ceiling are covered by washable plastic panels. The front fixed cantilever axle has hydraulic monoblock steering, and the drive axle is of type RABA with a dual ratio of 10.669. Both axles have pneumatic suspension composed of rubber bellows supplemented by hydraulic shock absorbers. The series 4-pole self-ventilated traction motor, insulated and hung on the body frame, has a continuous output of 100 kW at a traction voltage of 600V, and also powers a 28V/60A alternator, which powers the on-board control network and recharges the alkaline 160 Ah battery. The drive unit with pulse thyristor regulation and control regulator provides stepless control of power and electrodynamic braking, and permits smooth startup, along with automatic field weakening in two stages.
The brake system is composed of resistive electrodynamic brakes on the rear wheels, dual-circuit air brakes on both front and rear wheels, and a spring brake on the rear wheels, which acts as a parking brake.
The interior is lit with fluorescent fixtures with their own converters fed by the vehicle battery. Ventilation is provided by two ceiling exhaust fans and an openable hatch in the rear part of the vehicle. For cooler times of year, the vehicle has warm-air heating with a total output of 18 kW.
Two sprung rod trolleys provide traction electricity to the vehicle, and their design enables the vehicle to deviate from the trolley line axis by up to 4.5 m when speed is reduced appropriately.
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