Canada Buys British Trolleybuses
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Rear-mounted Control Equipment One of the Outstanding Features of a Fleet of A.E.C. Vehicles Built for Service in Montreal
THE seven A.E.C.-English Electric 38-seater six-wheeled single-deck trolleybuses, ordered by the Montreal ' Tramways Co., have recently been shipped to Canada. Particular interest attaches to them because they are the first vehicles • to be made by the Associated Equipment Co., Ltd., Southall, Middlesex, with the contactor panel and resistances mounted at the rear of the chassis—a patented arrangement of the manufacturer. When c.ommissioned they will bring the total number of A.E.C. vehicles operated by the Montreal Tramways Co. to 67.
The chassis used for these new trolleybuses presents some interesting features. The frame has a kick-up Over both front, and rear axles and, at the near side, a dropped section allows for a low entrance platform. The rear bogie has an offset worm to minimize gangway interference.
The layout of the power system follows the usual A.E.C. practice, in this instance a single compound motor, with a one-hour rating of 80 11.p., driving through a short propeller shaft.
The compressed-air equipment has several noteworthy points. Two independent reservoirs, fitted with nonreturn valves, are used—one for the brakes and one for door operation. The 5-cubic-ft. compressor unit is of the two-cy-lindered reciprocating type with a 500-volt motor. Air is drawn through a filter on one of the tubular cross-members, which acts as a silencer. The layout of the equipment, with the air reservoir check-valve and silencer mounted as a Unit, greatly reduces piping and facilitates maintenance. Both regenerative and rheostatic braking are obtainable on these chassis.
The direct-driven low-voltage generator is mounted at the front end of the motor. Separate yokes are provided for the main motor and generator, and the generator armature is built on a separate spider mounted on an extension of the motor shaft. The frame is bolted to the main motor end shield and the generator can be dismantled without disturbing the main motor. This 30-volt generator has a cut-in speed of approximately 3.75 m.p.h. Full load output of 1,600 watts is obtained at a roadspeed of approximately 5 m.p.h.
Apart from the master controller, all electrical-contactor equipment, resistances, etc., are mounted as a unit at the rear of the frame, access being provided through doors in the rear panelling. The whole unit is easily detachable, being arranged to slide reanvards out of the frame, Above the resistances is an aluminium-asbestos heat partition and longitudinal side shields prevent snow and mud, etc., thrown up by the wheels, from reaching the unit, but allow the free flow of air for cooling title resistances.
These A.E.C. English Electric trolleybuses have a wheelbase of 16 ft. 2 ins., an overall length of 32 ft„ and an overall width of S 'ft. 3 ins. The rear axle centres are extended to 4 ft. 4 ins, for the fitting of snow chains.
Designed to accommodate 35 standing passengers, in addition to the 38 for' which seats have been provided, the bodies are of the all-metal type constructed by Metropolitan CarnmellWeymann Motor Bodies, Ltd.
Entrance and exit openings are on the right side and both are fitted with double jack-knife,, pneumatically °per.ated doors controlled by the driver. In the 'case of the exit, pneumatic treadle mats cover the steps so that the doors when released by the driver may be automatically opened by passengers standing on the steps. The seats are of the tubnlar-frame type.
The severe Canadian winter has dictated the fitting of a special heating system comprising 15 B.T.H. 500-watt heaters in the passenger saloon and two 600-watt heaters in the driver's cab. For the retention of interior warInth the spaces between the roof and side panels are filled with aluminium foil, . An. interesting feature is the fitting of a new type trolley mounting which considerably enhances the appearance.