Lloyd Mandeno (1888–1973)

After being schooled in the Waikato and Auckland, Mandeno became a foundation student at the Auckland University School of Mines and Engineering. He graduated, however, from the University of Canterbury in 1909.

As Assistant to the Waipa County Engineer, he then designed some of the earliest reinforced concrete bridges for provincial and rural roads. He was next employed in the erection of the Hora Hora hydro-electric station for the Waihi Gold Mining Company – the first hydro station on the Waikato River.

After nearly two years as Borough Electrical and Waterworks Engineer at Frankton, which provided the original electricity supply for Hamilton, in 1915 Mandeno was appointed Tauranga’s Borough Engineer. He spent the next 12 years there and was responsible for greatly increasing the capacity of the Tauranga Borough Council's Omanawa Falls hydro-electric station. He also designed and supervised the construction of the McLaren Falls plant which was commissioned in 1925.

At the same time, during the 1920s he was associated with various mining ventures in the Otago, Westland and Coromandel fields. Mandeno also consulted for a number of other emerging supply authorities, in particular the Taupo Borough Council, King Country Electric Power Board and Bay of Islands Electric Power Board.

While he was in Tauranga, Mandeno devised and patented the single-wire earth-return (SWER) system of electrical reticulation which is now in use in many parts of the world as a means of distributing electricity cheaply over long distances. Other examples of his expertise are his pioneering of 11 kV distribution, the development of the first electric hot-water storage heaters, his early adoption of high-pressure hot-water heating systems and of forced circulation for hot-water heating, and the use of aluminium conductors for low-voltage overhead lines.

Mandeno’s professional work spanned over 60 years and he continued to be involved with electric supply authorities in a consulting capacity until just before he died.

For his development of the SWER method of distribution he was awarded the Office of the Order of the British Empire (OBE) in 1956, and in 1972 the Tauranga joint generation committee named its first power station to be commissioned in the Mangapapa scheme the "Lloyd Mandeno station" in honour of its eminent designer.

At the age of 82, he visited Fiji and reported on the hydro-electric potential of the Nandreau Plateau. At the time of his death, his report was the basis of a full-scale feasibility study.

Mandeno was elected to membership of the New Zealand Institution of Engineers (NZIE, now the Institution of Professional Engineers New Zealand, IPENZ) in January 1921 and took a lively interest in matters affecting the profession. He was a generous contributor to the benevolent fund. In 1947 Mandeno received a special NZIE award for his paper “Rural power supply”.

More information

Source

New Zealand Engineering, March 1974, p 96.

Further reading

Jinty Rorke. ‘Mandeno, Lloyd,’ from the Dictionary of New Zealand Biography in Te Ara - the Encyclopedia of New Zealand, updated 13 November 2013.