The building of two new historic restaurant trams in Melbourne posed a set of unique challenges for our electrical design team. For one, section insulators could not cause major issues to the operation of a complete kitchen and diners could not experience any indication of the major line voltage fluctuations. It was challenges like this that had the operators calling us for solutions.
Ultimately, we designed and installed a complete traction system to provide smooth control of the motors and an auxiliary power system to supply the single phase, two phase and three phase appliances at the required voltages.
Each restaurant tram consists of the following equipment which was designed/manufactured/installed by TTM Rail.
This was the first traction chopper to be installed on a historic W class tram on Melbourne’s network. The 120kW chopper was built in Melbourne, with client specific requirements kept in mind, in particular the smoother acceleration ramp to ensure the patrons’ food and drink remains on the table while dining on the tram. Individual motor power modules were installed to provide redundancy in the case of a motor fault. I.e. if one motor is faulty, the service can continue as that motor will become isolated, and the remaining three motors will continue to operate.
The original hand controllers were also modified internally to remove the 600VDC from the controller, and provide a safer, low voltage reference to the chopper, while increasing the reliability and simplicity of the system. The original feel of the controller was kept to ensure minimal driver training was required.
A single 26kVA Vossloh Kiepe KGU105 inverter with a custom designed underfloor mounted housing was installed to supply a complex mix of single phase, two phase and three phase systems all switching on and off as desired on the tram. This inverter alone is supplying the following voltages and loads:
The control circuit of the combi oven was also modified to run continuously, even through section insulators, to ensure the timers and cooking parameters are not reset.
A 15kW, 240VAC, single phase inverter was installed to supply the remaining loads on the tram. Due to the nature of the service, a Lithium Iron Phosphate battery backup system was also installed to supply the inverter over the section insulators, to ensure the power does not switch off for such items as the lighting, music and microwaves.
A backup lighting system was designed and installed to provide additional lighting in the saloon and drivers’ cabins for 5 minutes after the pantograph and battery are switched off, to allow safe manoeuvring for staff and drivers when shutting down the tram at night, or in the instance of a complete power loss.
The existing brake control on the W class tram consisted of a pneumatic operated governor, which switched the 600VDC supply voltage to the braking compressor. The 600VDC supply was delivered to the governor via a control switch and fuse in the drivers’ cabin.
As part of our customer’s commitment to provide a safer working environment for the drivers and staff, TTM Rail provided a low voltage 24V solution. Not only did this increase the reliability by replacing the obsolete, failure prone governor, but this also resulted in this 600VDC cabling being removed from the driver’s cabin.