Submarine Mines

In Colonial times the Sydney Harbour ( Portus Jacksonia ) defence as we have indicated in Barbacane ( https://pbase.com/galleria_rusticana/barbacane was well developed from the artillery viewpoint with elevated gun positions on the promontories surrounding the foreshores.
This was however not the only method of Harbour defence. In the 1890s Sydney Harbour was also defended by underwater mines which were moored on the seabed. The mines were located in a grid formation, marked by buoys and electrically detonated by cable. The detonation process was directed by observation from the shore as the target shipping moved into the grid pattern.
A considerable establishment was required to administer and operate the mine defence and the site in Sydney is the last available for study in the World. Special pay and conditions were assigned to the members of The Submarine Mining Corps involved which was finally disbanded in 1922. The main site building at Chowder bay can be seen on Google Earth 33 50 20.37 S 151 15 18.61 E. Eye altitude 200m. Also in this Google view are several of the WWll Naval Oil storage tanks. They are still in use and are the only gravity fed installation in the Australian region.
Substantial parts of the specialist establishment required for servicing and maintenance are still present and can be seen in the following photography.
Although the mines were never tested in battle, the system, state of the art for its day was on call for presentation to dignitaries from time to time and in the course of one demonstration in 1891 in the presence of the Governor and several thousand people there was a severe accident involving considerable damage and loss of life. By curious chance Maritimus ( https://pbase.com/galleria_rusticana/galleria_maritimus )
struck up conversation on a cruise with a fellow traveler to find that a now passed away relative had been a survivor of the debacle. There may be more to this tale when you visit next.
There is excellent coverage at Wikipedia go to :
http://en.wikipedia.org/wiki/Submarine_Mines
Rusticana received a considerable assist in notes and photography from Colonel Kenneth Duncan who was previously a commander of the Army Transportation School prior to its handing over to the Public in 1999. Ken took us over the Establishment and the adjacent gun battery and regaled us with many anecdotes of his considerable time spent in various responsibilities on the Site. Ken has also provided us with photographs from his collection. Thanks Ken.
Work in progress May 9th 2008