Karori Rock Lighthouse is situated on rocks at the west side of the Wellington Harbour Heads in Cook Strait.
Location: Latitude 41°21′ South, Longitude 174°39′ East
Elevation: 20 Metres above sea level
Construction: Concrete Tower
Tower height: 19 Metres
Light configuration: Aga Lantern
Light flash character: 0.5 second white and red flash every 4 seconds
Power source: Acetone Acetylene
Range: 9 nautical miles (white) 7 nautical miles (red)
Date light first lit: 1915
History of Karori Rock Lighthouse
After the loss of the Steamer Penguin in Feb, 1909 a light was planned for Karori Rock. There was some debate between mariners and the Government Nautical Advisor of the position of the light, some said it should be placed on Cape Terawhiti, others said Tongue Point. After a inspection on board the Hinemoa on the 10th December 1912 by the Minister of Marine (Hon. F. M. B. Fisher), the Under Secretary for Marine (Mr. G Allport), the Nautical Advisor to the Government (Captain Blackburne), the Engineer in Chief, (R.W. Holmes), and Captain Bollons, Captain of the Hinemoa it was decided to build the light on Karori Rock.
Karori Rock is about 400 sq feet, about 25 feet above sea level and during southerly winds is continuously covered in spray.
Construction commenced in June, 1913 and it was another difficult light to build as there was only room on the rock for 6 men to work. The rock had to be filled with a concrete foundation which could only happen in calm weather, often tools and newly poured concrete were washed away by southerly swells. The work was supervised by the Marine Department lighthouse superintendent Mr. Frazer. and the job foreman was Mt Johnson.
A concrete mixer and a small jetty were erected on the mainland and a small launch was used to transport the mixed concrete out to the site. The concrete was poured into drums, and about 3/4 cubic yard contained in ten drums could be transported at one time. A small crane was used to winch the drums off the launch and pour the concrete on site. About 8 cubic yards could be poured on a good day.
To build the foundation, holes had to be drilled in the rock for the reinforcing rods and bolts to hold the wooden framework for the concrete. Even using 1 inch bolts, this whole framework was washed away once by heavy seas. The tower is of cylindrical shape and is 20 feet by 10 feet, while at the top it is 15 feet by 10 feet. The tower rises 39 ft. The tower was deliberately built with three sides vertical and one side on an angle with steps formed in the concrete and a metal ladder attached. On the top of the tower the lantern room was erected, along with a small crane and this was enclosed by a parapet. The lantern room measured 10 feet to the focal plane, 15 feet overall, giving the light a total height of 79 feet.
The light apparatus known as a Aga lantern, was imported from Sweden and the light was a 500mm drum lens using Acetone acetylene to fuel the light and was operated by a sun dial. Displaying 2790 candlepower, the light had a character of 1/2 second every 3 1/2 seconds.
The lighthouse tender Hinemoa was used to land equipment and stores. Fresh meat and bread were packed in on horseback from Makara.
The light was first lit on October 20, 1915. It was reported to be 65 feet high at that time.
The lighthouse was serviced by lighthouse tenders with the gas cylinders being changed regularly, however due to bad swells it was difficult to service.
In May 1996 it was replaced with a new Vega 250 flashing beacon on the mainland at Tongue Point. The original Karori Rock lens still remains in the tower.