Grotto Point lighthouse

2008
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Grotto Point lighthouse

The lighthouse at Grotto Point is one of the two leading lights into Sydney Harbour. Early European settlers recognised the importance of the location at the northern tip of the entrance to Middle Harbour. Lieutenant William Bradley, who carried out a survey of the northern part of the harbour early in 1788, wrote on the evening of 28 January 1788:

We went to Grotto Point, moored the boats and made a tent fore and aft the longboat, in which we all slept.

Grotto Point was one of only a handful of local spots to be named on the maps produced following the survey, taking its name from a fragile natural stone arch at the tip of the point, which was probably destroyed by a storm soon after the arrival of the First Fleet.

James Larmer surveyed Joseph Hicks's grant of 20 acres (eight hectares) on the western side of Grotto Point in 1830, and William Yates was granted 20 acres at Castle Rock nearby in 1836. The point itself was granted by purchase in 1853 for £20 to William Clarke, who sold it to George Allen in 1854 for £40. No use was ever made of the grant and eventually the land was resumed by the crown.

A pair of leading lights for Sydney harbour

Following a conference of shipping interests and harbour authorities in 1909, it was decided a new system of harbour navigation lights and beacons was needed. Plans proposed a pair of lights, one on Grotto Point and one on Parriwi Point, as the leading lights into the harbour. The Parriwi Point light is spaced exactly one mile behind the Grotto Point light, which was built 18.6 metres above high water.

The Grotto Point light is a white-painted masonry and brick tower, eight metres high, with a domed roof, adjoined by two barrel-vaulted sections and surrounded by a white picket fence. A horizontal slit on the seaward side of the tower, measuring two metres by one metre, provides an opening for the light. Grotto Point light is fitted with a catadioptric lens, meaning a combination of reflection and refraction of the light; while the horizontal slit has red, white and green sectors, with white in the middle. A ship in the red or green sectors must change course into the white sector, then line it up with the flashing green light on Parriwi Point before entering the harbour. The Grotto Point light is occulting, where the period of light is longer than the period of darkness, while the Parriwi light is flashing, where the period of light is shorter than the period of darkness.

Construction of the tower began in 1910, and the light was first exhibited on 1 September 1911. Acetylene gas for the light was initially generated on site, then replaced by cylinders of compressed gas brought to the site and landed at a jetty on the western side of the point, until the light was eventually converted to electricity from the suburban grid. The land surrounding the light, corresponding to the boundaries of Clarke's 1853 grant, was dedicated for public recreation in November 1911, only to be revoked and re-dedicated in June 1912. The lighthouse is now within Sydney Harbour National Park.

References

John Morcombe, 'Grotto Point Landmark', Manly Daily, 11 December 1996

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