Bringing light to part of Tiritiri Matangi history

Author: Jonathan MowerDate: 23/04/23

On January 1, 1865, the new and then richly red Tiritiri Matangi lighthouse first shone its light over the Hauraki. Although that light has been continuously operational since that day, how the light has been generated has changed many times. First lit by colza/canola oil, it changed consecutively to using paraffin, and acetylene, then to electricity first from diesel generators, then from a cable link to the national grid, then reverted back to diesel generators and ultimately to solar power with diesel generator backup as it remains today.

Cyclone Gabrielle and other weather events in February caused deep scouring to parts of the island’s coastline and in doing so brought to light part of this history when it uncovered parts of the submarine cable that in 1967, linked the island to the national grid and ended years of diesel power generation. Laid across the sea bottom, the cable stretched in a loop from Pink Beach near the end of Whangaparaoa Peninsula, across Whangaparaoa Passage to Tiritiri Matangi Island where it exited at the northern end of Hobb’s Beach and travelled inland.

The mains cable was actually two seperate cables; the marine cable and the land cable and the two were joined within a bolted and braced wooden structure.

Although the laying of the marine cable was said to have required meticulous planning but it went without a hitch,’(1) maintaining the power connection was not so simple. Marine cables are prone to be damaged by fishing boats and other vessel’s anchors and Tiritiri Matangi’s cable proved no exception. Sometimes the damage would cause cable failure and for Tiritiri Matangi, this was a serious issue as it meant a loss of power not only to the island’s facilities but also to the lighthouse which required an urgent switch to backup generation. Recently Ray Walter, the island’s last lighthouse keeper, recounted one such failure that he discovered while milking. “I was milking the cow, and the cups kept falling off, so I went and had a look, and we had lost one of the phases from the power.”

The marine cable exiting the Whangapraoa Channel and arriving onto Hobb's Beach shoreline. The cable is armoured with spiral metal braiding that protects the conductors within the cable but even that was not sufficient to prevent damage by boat anchors.

In 1989, after the cable had failed for the third time, the island was removed from the national grid, and the island reverted to diesel generator supply where it remained until 1990, converting to solar power generation with diesel backup as it remains today. This was not the first cable to connect Tiritiri Matangi to the mainland, however, a marine telephone cable was laid from Waiwera to the island in the mid-1880s using funds donated by Auckland businessmen. Terminating at a small glass, octagonal-shaped phone booth with a curved pagoda-shaped roof, sited on the slopes south of the lighthouse. The telephone line linked the island to the mainland until not long after 1928 when it was lost in a storm. Sourced “Tiritiri Matangi, A Model of Conservation” 2009, by Anne Rimmer.

(1) Jack Gladwell, ‘Mains Power to Tiri Tiri Island’, Ministry of Works Gazette, vol. 4, no. 3, September