The Balmain Tramway Substation and Battery House in Rozelle.

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Hancock Street - Tramway Buildings

These buildings are tucked away in a back street in Rozelle, quite near the intersection of Victoria Street and Darling Street. The building at the left was the battery house and the building at the right was the tramway substation. This location is ideal to supply power to trams coming up the hill from White Bay and to trams going along Darling Street to Lilyfield and Leichhardt.

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Hancock Street - Battery House

Initially, power for the trams came from the tramway power station in Ultimo (now the Powerhouse Museum and soon to be sold to developers and demolished). Batteries were installed at Rozelle to keep the voltage high during peak hour by providing power locally. The idea was that the batteries would be recharged during the night with power from Ultimo.

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If you peer through the windows of the battery house, you can see it's not an ordinary house but is one large room. The batteries were lead-acid cells each providing a little over 2 volts. This means close to 300 cells to provide the 600 Volts DC needed for the trams. Photos of battery houses show very similar technology to that used in telephone exchanges before 1940. Many battery houses across Sydney served the tram network. The capacity of the battery is given as 500 amps and this indicates a worthwhile contribution to powering the nearby tram network for several hours. For comparison, South Australia's huge new battery can power their state's electricity grid for less than a minute.

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Hancock Street - The Balmain Substation

The taller building on the right is best described as a machine hall. The standard technology of the day was a large electric motor powered from the commercial mains turning a 600 volt generator to supply the trams. It's all spinning on one shaft to keep the design simple. Photos from the Abbotsford substation in 1922 show huge electric motors about 2 metres in diameter. For the sake of reliability and maintenance, it was normal to install several of these motor generator sets. As recorded in 1914, the Balmain Substation had four 450 kW units.

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A side view of the machine hall. The tall windows indicate it was a one story building with a high ceiling.

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This rear view shows a very high roller door. Such a door is needed for cranes to lift machinery into the building.

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Hancock Street - Power Connections

This small tower was used to support the wires needed to feed power from the battery and the generators out to the trams. White porcelain insulators are set into the brickwork so that the 600 volt cables can safely leave the building. The tower has feed holes on three sides. This meant cables would have run towards Victoria Road and towards Darling Street.

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Here is a close-up view. It's looking a bit rusted now, but power cables passed through the white porcelain holes and were then supported by the brown insulators. It was out in the weather and it had to be simple and reliable.

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Hancock Street - Plaque

This modern plaque correctly identifies the building as a Tramway Substation. However it's seriously in error on two counts. Firstly it says the buildings were built together in 1907. This is unlikely, since one building is clearly cut into the other. Sydney's best tramway historian recorded that the battery was available from 1903 until 1913 and the substation from 1909. Secondly it says the building contained turbines which is incorrect. Spinning yes, but turbines no. This turbines concept results from over-enthusiastic real estate agents making up stories for the local newspaper and a few inexperienced heritage consultants being fooled by waffle.

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