Inside The Ward St substation

The substation. Photos by Linda Robertson, DCC Archives.
The substation. Photos by Linda Robertson, DCC Archives.
Bombproof casing in place during World War 2.
Bombproof casing in place during World War 2.
Switchgear at the substation in its heyday - disconnected but still in place.
Switchgear at the substation in its heyday - disconnected but still in place.
A portable phase meter.
A portable phase meter.

It comes from an age when utilitarian purpose did not preclude elegant design of the very latest fashion. The Ward St substation is one Dunedin's finest infrastructure buildings, an art deco masterpiece that once provided careers for tidy, introspective loners.

The Ward St substation (actually in Bauchop St) sits quietly humming in Dunedin's industrial sector.

It sits mostly quietly humming, to be more accurate.

Because every now and then the ripple control kicks in and the hum takes on a sharper pitch, a sort of subtle crackle as the ripple signal uses its 1050Hz frequency to do stuff like turning your hot water on or off, or controlling elderly nightstore heaters.

Ripple control is one of the few things that appear vaguely easy to understand in the jargon-heavy, opaque world of the electricity engineer.

In Ward St, generations of overall-clad workers have understood 7.5 megavolt ampere (MVA) synchronous condensers and 1875kW Brush Ljungstrom steam plants with Babcock and Wilcox oil-fired water-tube boilers, 24MVA 33/11-6.6kV transformers and 11kV switchgear.

The substation is a building so worthy of housing equipment so beautifully named, because the structure is a triumph of form and function, angular and geometric with strong foundations in early 20th-century modernism, celebrating the joy of the sunlight that streams through its huge arched windows.

It is a building born in the shadow of war, and still carries the fears of the late 1930s.

The substation was the second to be built in Dunedin, after the Halfway Bush station, between 1937 and 1939.

The Bauchop St windows still sport the original wire-reinforced glass that, along with an original camouflage green paint job and a massive bombproof casing that once stood dark and staunch over some of the substation's equipment, was there to protect the essential infrastructure from German or Japanese bombs.

The windows once sported blackout curtains to the same end, and a camouflage pattern can be seen in the architect's drawings for the building's roof.

Today, the substation belonging to Dunedin City Council-owned company Aurora supplies electricity to 1450 consumers from the eastern inner city to St Leonards, including Cadbury, Ravensdown and Forsyth Barr Stadium.

It bravely holds on to one end of a pair of 33kV high-pressure nitrogen gas cables that snake under the city and through its hills to Halfway Bush.

Those cables carry a massive 33,000 volts, which is stepped down to 11,000 volts at Ward St, before more cables are fed out to street transformers that cut it down to 400 volts or 250 volts for homes and businesses.

Inside the substation is half museum and half shiny, humming new electricity equipment run by computer and controlled from elsewhere.

Under an electric clock that stopped at 1.52 many years ago, past the now defunct reactor and the ripple control injection equipment stands the handsome 6.6kV Reyrolle switchgear, disconnected now, but still standing in all its grim finery.

The Reyrolle is a construction of some utilitarian beauty, studded with meters, switches and buttons that beg to be tapped, switched and pushed.

Further inside the building, cables emerge from underground, before multiplying and twisting upstairs into a bank of more modern and much less romantic-looking infrastructure.

In a small room off the main area of the substation sit the most stunning examples of historic electrical tools, including a beautifully crafted portable phase meter in a solid wooden surround that would have been used by electrical types in the field in years gone by.

Those years, of course, were a simpler, gentler time when a fellow with a broom, overalls and a love of quiet introspection could flourish.

There was always one person on duty at the substation, and the facility had to be manned 24 hours a day, seven days a week.

Because staff were there only to react to a problem, they would have had plenty of time to contemplate the mysteries of electricity infrastructure, and were doubtless wise beyond the perception of ordinary people by the end of their career.

The substation was also known in those days, perhaps unsurprisingly, for immaculate tidiness.

But most importantly, the one meditative, overalled, broom-toting, tidy occupant of the substation was tasked with writing, in neat, cursive longhand, every half-hour, voltages and the like in a logbook for posterity.

You just can't get jobs like that nowadays.

At the end of a tour of the Ward St substation, one emerges into the crisp industrial air of the yard.

There, stand two mighty, fan-cooled transformers, named, in the sparse nomenclature of the 21st century, T1 and T2.

These humming behemoths transform the almost ungovernable power that pours from massive dams across Otago, tame it and send it crackling through wires to your home and workplace.

It is hard to decipher the signature of the city electrical engineer who signed off the architectural drawings for the building back in the 1930s; perhaps it was Harrison, perhaps Henderson.

We all, however, owe him a deep debt of gratitude.

Hip hip hooray, sir.

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