History of Cape Naturaliste Lighthouse

History

The lighthouse was built in 1903. The contractor was Mr Anderson who commenced work on 11th February, 1903 and finished on 11th December that same year. The contract price was £4,800 ($9,600) and the official opening was in April, 1904.

The base of the lighthouse is about 110 metres above sea level and the light approximately 123 metres above sea level giving a range of 26 nautical miles, out to the horizon, in clear weather.

The limestone for the lighthouse and cottages was quarried near Bunker Bay and carted back to the site by bullock wagon. Most other materials were unloaded from boats at Eagle Bay/Quindalup.

The lenses, made of Prism Crystal and originally costing about £5,500 ($11,000), were made by Chance Bros. Birmingham, England. All the parts were supplied in kit form and put together as the tower was constructed.

The original kerosene mantle gave a light of approximately 1455 candlepower which was magnified 836 times giving a reflected light 1.2 million candlepower. The light source is now a 120 volt 1000 watt tungsten halogen globe with a similar backup globe. There is also an onsite battery bank backup in case of power failure. An alarm system was connected to the keeper’s house in case of a complete breakdown.

The turntable was originally driven by a clockwork mechanism operated by a weight of approximately 180kg, giving one revolution every 10 seconds. With the setting of the lens this gives a flash character of two flashes every ten seconds with intervals of two and a half seconds and seven and a half seconds. The weight had to be rewound every 40-50 minutes through the night.

The lens and turntable, which weigh approximately 12 tonnes, float on 156.5kg of mercury contained in the pedestal underneath. A bearing at top and bottom of the pedestal holds everything in an upright position.

The windows around the lighthouse had to be curtained during the day to eliminate the sun as the lens would act as a giant magnifying glass and break prisms, windows and start fires in the surrounding scrub.

Originally, three families occupied the cottages and each keeper worked his night shift to wind the clockwork and maintain the kerosene pressure. When the lighthouse power supply was converted to electricity, operations were then controlled by one keeper. He was on duty seven days a week and was only relieved for his annual holidays. The lighthouse has now been converted to fully automatic operation. Cape Naturaliste Lighthouse was the last lighthouse in Western Australia to lose its keeper in 1996.