View source for Lower Georges Heights Commanding Position

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[[Image:MiddleGeorgeshedfort0191.JPG|thumb|The main entrance to the fortification command position at Georges Heights]]
[[Image:MiddleGeorgeshedfort0207.JPG|thumb|Gun emplacements on site]]
[[Image:SydHarbourdefence0008.JPG|thumb|]]
The '''Lower Georges Heights Commanding Position''' is located in the urban locality of [[Georges Heights, New South Wales|Georges Heights]] in the suburb of [[Mosman]], on the shores of [[Port Jackson]], [[Sydney]], [[New South Wales]], [[Australia]]. 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 Harbour defences|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.<ref>http://commons.wikimedia.org/wiki/Image:MiddleGeorgeshedfort0195.JPG {{Dead link|date=February 2022}}</ref>

The two cannons that were first placed at the site were [[RML 9 inch 12 ton gun]]s. [[Muzzle-loading rifle|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&nbsp;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&nbsp;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 Mk VII naval gun|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&nbsp;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==
<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.
</gallery>

==References==
{{Reflist}}

==External links==
{{Commons category}}
*[https://web.archive.org/web/20071107233007/http://www.harbourtrust.gov.au/topics/sitesmiddlehead.html#history www.harbourtrust.gov.au Middle Head history.]
*[http://www.ozatwar.com/bunkers/middleheadfortress.htm www.ozatwar.com / Australia @ war.]
*[https://web.archive.org/web/20070822230652/http://australianbunkermilitarymuseum.org/joomla/index.php Australian Bunker and Military Museum.]

{{Barracks Batteries Bunkers and Forts in Sydney}}

[[Category:Artillery battery fortifications in Australia]]
[[Category:Bunkers in Oceania]]
[[Category:Forts in New South Wales]]
[[Category:History of Sydney]]
[[Category:James Barnet buildings in Sydney]]
[[Category:Military history of New South Wales]]