The History

The building was built in the late 1940s as a tramway traction substation, rather than a normal neighbourhood distribution substation.

the building contained:

transformers
rotary converters or mercury-arc rectifiers (later solid-state equipment)
switchgear
control rooms
Their sole purpose was to convert AC electricity into DC to feed the overhead tram wires.

1956 – End of the trams

Auckland's last tram ran inDecember 1956, when the network was replaced by trolley buses and diesel buses. Once the tram system disappeared, traction substations were no longer needed for their original purpose.

Reused as a Joint Training School

Instead of demolishing a perfectly solid concrete building, the former traction substation became a training facility where apprentices learned skills such as:

cable jointing
lead-sheathed cable work
underground cable installation
overhead line splicing
transformer maintenance
switchgear operation
electrical safety procedures

The "joint" in Joint Training School referred to cable jointing, one of the most specialised trades in electricity distribution. Before modern pre-moulded joints became common, jointers had to hand-build insulated joints in paper-insulated, lead-covered cables—a highly skilled craft.

1980s–1990s

By this stage:

Auckland's electrical industry had changed dramatically.
Modern polymer-insulated cables largely replaced paper-insulated lead cable.
Training increasingly moved into dedicated technical institutes and company depots.
After the electricity industry reforms of the late 1980s and early 1990s, many surplus buildings owned by the former Auckland Electric Power Board were sold.

The property sold in 1996, and the prior owners began the conversion into a residential home rather than an industrial property.

Many features of the house today exist because of its former purpose:

Solid reinforced concrete walls (designed to withstand heavy electrical equipment)
Steel-framed windows (crittall)
Very high ceilings which were for transformers and switchgear
Industrial steel doors
Thick concrete floors capable of supporting extremely heavy transformers
built to withstand a natural disaster like an earthquake
Minimal decorative detailing, reflecting its purely functional purpose

There are now 20 substations in Auckland, seven of these were built in the same art deco era and three have been converted into residential homes, Mt Eden, Ponsonby and Onehunga, the rest are still operating as working substations.

The End of the Line - 1956
For more than half a century, electric trams connected Onehunga with central Auckland as part of what was, remarkably, the world’s only coast-to-coast tramway system.

In 1956, Auckland’s last tram lines were decommissioned as the city embraced buses, motorways and the private car.

With Auckland now investing billions in rapid public transport and rail infrastructure, it’s hard not to look back on that decision as a little shortsighted.

The History

The End of the Line - 1956 For more than half a century, electric trams connected Onehunga with central Auckland as part of what was, remarkably, the world’s only coast-to-coast tramway system.

In 1956, Auckland’s last tram lines were decommissioned as the city embraced buses, motorways and the private car.

With Auckland now investing billions in rapid public transport and rail infrastructure, it’s hard not to look back on that decision as a little shortsighted.

The photograph captures the end of an era — the last tram through Onehunga, 1956.

The End of the Line - 1956
For more than half a century, electric trams connected Onehunga with central Auckland as part of what was, remarkably, the world’s only coast-to-coast tramway system.