The Lower Georges Heights Commanding Position is located in the urban locality of

Georges Heights Georges Heights is an urban locality in the suburb of Mosman, adjoining Sydney, in the state of New South Wales, Australia. Georges Heights is located in the local government area of the Municipality of Mosman and is part of the Lower North ...

in the suburb of

Mosman Mosman is a suburb on the Lower North Shore region of Sydney, in the state of New South Wales, Australia. Mosman is located 8 kilometres north-east of the Sydney central business district and is the administrative centre for the local governm ...

, on the shores of

Port Jackson Port Jackson, consisting of the waters of Sydney Harbour, Middle Harbour, North Harbour and the Lane Cove and Parramatta Rivers, is the ria or natural harbour of Sydney, New South Wales, Australia. The harbour is an inlet of the Tasman Sea (p ...

Sydney Sydney ( ) is the capital city of the state of New South Wales, and the most populous city in both Australia and Oceania. Located on Australia's east coast, the metropolis surrounds Sydney Harbour and extends about towards the Blue Mountain ...

New South Wales ) , nickname = , image_map = New South Wales in Australia.svg , map_caption = Location of New South Wales in AustraliaCoordinates: , subdivision_type = Country , subdivision_name = Australia , established_title = Before federation , es ...

Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...

. The Lower Georges Heights Commanding Position was constructed and designed to stop enemy ships from entering into Sydney Harbour, and worked in conjunction with several others forts located within close proximity.

History

The fortification was built in 1877 and became part of the Sydney Harbours outer defences. At the time this method of fortification was considered to be the most efficient way of defending this entry point into Sydney Harbour.http://commons.wikimedia.org/wiki/Image:MiddleGeorgeshedfort0195.JPG The two cannons that were first placed at the site were

RML 9 inch 12 ton gun The RML 9-inch guns Mark I – Mark VIMark I – Mark VI = Mark 1 through to Mark 6. Britain used Roman numerals to denote Marks (models) of ordnance until after World War II. Hence this article describes the six models of RML 9-inch guns. were lar ...

s. Rifled Muzzle Loaders (RMLs) are artillery pieces loaded from the muzzle, but with a rifled bore liner, invented in the mid-19th century. In contrast to smooth bore cannon which preceded it, the rifling of the gun barrel allowed much greater accuracy and penetration as the spin induced to the shell gave it directional stability. Initially smooth-bore cannon were converted into rifles by re-boring and lining; but later new guns were manufactured from scratch as RMLs. The RML 9 inch 12 ton gun could discharge shells weighing 249 pounds (113 kg) as far as South Head (Watsons Bay); approximately 3,000 yards (2,770 metres). As technology improved, these cannons were replaced in 1889 by much lighter weight guns that could fire an 80-pound (36 kg) projectile for 3,170 yards (3,000 metres). From 1903 to 1907 the fortifications were upgraded to allow for the installation of two BL 6 inch Mark 7 guns that were “breech loading” which meant that the explosive charge and projectile were to be loaded into the rear of the cannon. They could fire a 100-pound (45.4 kg) shell a long way out to sea; up to 14,000 yards (12,900 metres). The underground rooms of the fortifications were used to store ammunition and charges which were brought along Military Road, giving the road its name.

Gallery

Image:MiddleGeorgeshedfort0193.JPG, Main tunnel as seen from the main gate Image:MiddleGeorgeshedfort0198.JPG, One of the rooms inside the fort. Image:MiddleGeorgeshedfort0202.JPG, A shaft that leads down into the forts tunnel system.

References

External links

www.harbourtrust.gov.au Middle Head history.Australian Bunker and Military Museum.
{{Barracks Batteries Bunkers and Forts in Sydney Batteries in Australia Bunkers in Oceania Forts in New South Wales History of Sydney James Barnet buildings in Sydney Military history of New South Wales