New Zealand’s first lighthouse was built in 1858. With technological advancements, the lighthouse keeper has been replaced by fully automated computer-monitored lighthouses.
Built in 1858, Pencarrow Head lighthouse, near Wellington, is the oldest lighthouse in New Zealand. This was also the only lighthouse in New Zealand to ever have a woman as lighthouse keeper.
The first locally-built lighthouses had fixed lights which did not flash. Because of this they were easily confused with other lights along the shoreline, and were eventually phased out.
The first lights were fuelled by colza oil, a derivative of the rape plant. Colza oil was later replaced by cheaper paraffin oil. These early lamps had a long wick which required constant trimming throughout the night, for the light to burn bright and clear.
Lights which had a lens that revolved round a single lamp by means of a clockwork mechanism replaced the fixed lights. This gave the effect of a flashing light. The mechanism was run by weights that were suspended down the tower shaft. One of the keeper's most important jobs was to wind up this mechanism. If the light stopped revolving it could cause as much confusion as if the light was out altogether.
In 1865 the first revolving light was installed at Dog Island lighthouse. The light used 16 small oil lamps, each with its own lens. It was a forerunner of today's electronically driven revolving lenses.
The average lens on the early lights weighed several tons, requiring a strong mechanism to keep the system of wheels or ball-bearings moving. This restricted the size of the lantern, reducing the power and speed of the light. In the late 1880s a new type of lantern was invented. The new lights floated on a bed of mercury rather than on metal rollers, allowing easier and faster revolutions.
In the 1900s, incandescent kerosene burners were introduced. They provided economy with a more brilliant light and with no wick trimming required at all. Most of these kerosene-fuelled lamps lasted until around the 1950s, when the lighthouses were gradually all converted to electricity.
In the 1950s, all lighthouses in New Zealand were converted to electricity, accelerating the move to automatic lights.
A typical New Zealand lighthouse has a lens that revolves around a 1000-watt bulb. Most lenses are made up of a number of sections that magnify the bulb light into beams. The lights are automatically switched on by a photoelectric daylight sensor. This sensor sends 12 volts of power to the lighthouse, either from the mains electricity system, diesel generator or by solar power. Some 70 lights are now generated by solar power.
The main lights and beacons around New Zealand are now monitored remotely in Wellington by Maritime New Zealand. The computerised active control system enables our lighthouse engineers to check any faults via computer, and to troubleshoot most problems remotely. The rotation gear, lamp and power supply all have standby units that are automatically activated if there is a failure. Any faults are automatically relayed by computer to Maritime New Zealand.
All classic lighthouses are now maintained and inspected on a 6-monthly basis. Access to each lighthouse is kept clear, the structure kept sound, weeds are removed and all vegetation that could pose a fire hazard in the summer is cleared away. Some technical maintenance is done on each light, mainly on things such as diesel generators. The lightbulb on the main lights needs to be changed every 6 months.