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Home RUNNING JOURNAL Reflections Cover Photo : Mal Rowe

This article was published in the August issue of ASEA ACTION, and ELECTRICAL DEVELOPMENTS, journal of the Electrical Development Association of Victoria.


We thank Bob Prentice for obtaining permission for its reproduction in "R.J.", and the M.&M.T.B. staff concerned for producing the photographs used in the illustrations.


A new era in Australian intra-city transport has been ushered in with the Melbourne and Metropolitan Tramways Board's recent order for 100 new trams. These will replace some of the 700 vehicles already serving Melbourne metropolitan routes.


The contract for manufacture of the trams, worth more than $12,000,000, will be carried out by the Commonwealth Engineering, Dandenong, Vic., with ASEA Electric (Aust.) Pty. Ltd, as subcontractor for the electrical equipment, which accounts for some $6 million of the total contract.


The new vehicles will take tram travel to new levels of comfort, quietness, speed and efficiency for both passengers and crew, in line with detailed specifications drawn up by the MMTB, after Board officials had inspected tramways throughout the world.


As a result, the new generation Melbourne trams will have these characteristics:


COMFORT:

* Central heating in winter and forced-draught ventilation in summer.

* Special electronic controls to give completely smooth acceleration and deceleration.

* All-round vision, with no window obstructions at eye-level and out-front view past the driver, as in buses.

* Foam rubber seating throughout.

* More room inside - maximum of 48 seated passengers and a total of 125 including standing passengers, in a vehicle longer than the present trams.

* Fluorescent lighting.

* Luggage racks.

* Windshield wipers, sunshields and blinds.

* Ticket tidies and ticket and change-issuing machines.


SAFETY:

* Safety glass on all windows.

* Sensitive edge doors to prevent injuries to passengers.

* Exit step switches to keep doors open while passenger is on the step.

* Vigilance and "dead man" control" The driver's foot must be on the "dead man" pedal to allow motors to operate.

* Three-way braking (a) dynamic, through motors generating and the power being absorbed in resistors; (b) spring-operated and electrically-released disc brakes; and (c) emergency brakes which bear on the track in an emergency stop.

* Flashing-light turn indicators, stop and tail lights and adjustable rear mirrors.

* Automatic pole retraction. If the pole comes off the overhead line, it automatically retracts to the roof, thus avoiding possible damage to the overhead system.


QUIETNESS:

* Resilient wheels, made up of metal and rubber "sandwich".

* Rubber springs throughout.

* Electric brakes thus, no noisy air compressor.

* Sound insulation throughout body. Wheel slip control and automatic sanding to prevent skidding during braking or accelerating.

* Track brakes for emergency stops will avoid development of noise-producing "flat spots" on wheels.


The new trams will be capable of a speed of 45 m.p.h. (72.41 k.p.h.) compared with about 30 m.p.h. (48.27 k.p.h.) for the existing MMTB vehicles.


The driver, who has armchair-type seating, controls speed and braking of the tram by two pedals, while a third is kept depressed as a "dead man" control.


Destination signs are changed automatically from the driver's control panel. Selection of the required sign and route number is by push-button control, which actuates a memory device. This selects the correct number and destination from a magazine of plates in each sign box.


Each tram is fitted with a public address system.


ASEA has had considerable experience in the design and construction of tramway equipment, and part of the sub-contract will be to supply Commonwealth Engineering with drawings of the ASEA-equipped trams used in the Gothenburg (Sweden) urban transport system, and also manufacturing drawings to assist in the production of the fabricated parts of the bogies.


ASEA will supply the entire control electrics and driving mechanisms for each tram, including four traction motors (each rated 52kW or 75 h.p.), gear boxes, disc brakes and track brakes.


Other ASEA-supplied equipment will include the contactor and electronic motor controls, driver's control panel, sanding control, speedometer, the complete rubber suspension system, and resilient wheels.


The contactor control equipment will be supplied from ASEA's Lilydale factory and the traction motors from the company's Tottenham plant.


Acceleration control is via a potentiometer. An electronic device selects the correct number of contactors to short out the starting resistors, with an over-riding control of the acceleration rate.


This device incorporates wheel-slip control, where the speeds of both bogies are compared. Any difference, indicating wheel-slips results in an automatic reduction of acceleration rate.


If the slip continues, deceleration may continue until power is removed entirely.


A similar process takes place to prevent wheel-slip during braking.


Rubber is used extensively in the suspension system. A sandwich of rubber and steel acts as a spring on each wheel, while on the wheels themselves, rubber inserts are placed between hub and rim.


Disc brakes mounted on the motor shaft ensure smooth and effective braking and eliminate the tyre wear experienced with shoe brakes.


The winter-time heating system derives from heat generated in the starting resistors, which is ducted to the tram interior. In summer, it is exhausted to atmosphere and in addition, forced draught cool air is provided by ventilation fans in the ducting system. Variable speed ceiling fans are also used to control ventilation.


All Melbourne trams can be driven from either end, and begin return journeys on a crossover from one track to another. European trams drive from one end only and return on a loop at each terminus.


The "double-drive" requirement, and also the need for trolley-pole collection of power, instead of pantographs as are usual in Europe, were important considerations in the design specification.


The specifications also advised tenderer's that the design should be compatible with the possible future placing of the tramways system underground.


Power for the tramways system is purchased by the Board at 6.6kV and broken down by transformers and rectifiers to 600v DC in 26 sub-stations "


Rotary converters, glass pump, and pumpless steel tank, mercury arc rectifiers and silicon rectifiers are used for rectification.


New Era for Tram Travellers Volume 10, Number 6 December 1973

Photo: M.&M.T.B. - No.1041, the prototype of Melbourne's future fleet of new and improved trams. Exterior features include twin trolley retreivers, twin headlights and stoplights, turning lights, folding rear vision mirrors and side route number indicators. The side panels are painted orange with a brown lower band, the window frames are cream and the roof "Oriental Gold".


Photo: M.&M.T.B. - The drivers compartment showing the instrument console and foot controls. The drivers microphone is connected to a public address system for use both inside and outside the car.

Photo: M.&M.T.B. - Interior view of No.1041 showing the conductors elevated work station and the general seating layout. The lift up seats in the foreground can be locked in the raised position to create a larger passenger holding area between the front entrance door and the conductor. Other features include ceiling mounted ventilation fans, luggage racks and a conductors microphone for the public address system.


Photo: M.&M.T.B. - The centre exit facility of Melbourne's new prototype tram No.1041, showing the driver controlled illuminated sign, passenger press button and the bi-folding doors.