Brunswick West Mercury-Arc Tramway Substation
The Brunswick West tram substation was commissioned in 1936 to accommodate increasing tram traffic on the northern part of tram route 55. It has operated continuously over the 82 years since then.
It has recently been replaced by a new ‘package’ silicon diode rectifier substation on another site. As such the substation has been shut down and DC cable connections from it to the tramway overhead and rails removed.
The substation still has its 600 kW Hewittic glass-bulb mercury-arc rectifier equipment intact. The substation is accommodated in an imposing red brick building occupying a prominent position in the ‘Y’ junction of Dawson Street and Melville Road. A large opening in the front wall of the building is fitted with chain-wire gates with the oil cooled rectifier transformer clearly visible behind the gates.
The equipment in the substation includes incoming 6,600 Volt (AC) switchgear housed in tall brick cells; four glass bulb Hewittic brand (manufactured in the UK) mercury arc rectifiers; a high-speed circuit breaker in the negative side of the DC circuit; an open five-panel switchboard with 600 Volt DC +ve side circuit breakers and other control equipment including current limiting resistors.
Mercury-arc rectifier installations are now very rare worldwide. For this installation to have continued in operation until 2019 is extraordinary. Although now decommissioned the equipment is still in a serviceable condition and could be restored to operation. The engineering heritage importance of this rare installation cannot be over-stated.
This site has been approved as a virtual site as access to the general public is not available. there will be no ceremony, marker or interpretation panel at this site.
Engineering Heritage Recognition Program
| Marker Type | Engineering Heritage Marker (EHM) |
| Award Date | November 2019 |
| Heritage Significance | This substation is the last remaining mercury-arc substation previously supplying 600 Volt DC power to the Melbourne Tramway system. No substation of similar age and equipment is known in the tramway or railway systems in other Australian states. The conservation of similar substations in other countries is not known. |
| Nomination Document | Available here. |
| Ceremony Booklet Ceremony Report |
Not Available. |
| Plaque/Interpretation Panel | Not Installed. |
