Hundreds of people drive past every day, and most would not even know that the amazing tunnels of the Leighton Battery are there.
But thankfully the Northshore SES unit does know of the tunnels existence, and the site has proven time and time again to be a fabulous training ground for its volunteers.
Hidden away just off Stirling Highway in Mosman Park, the Battery has a commanding view of the sea approaches to Fremantle. The 300 metres of underground tunnels were completed in 1943 having been cut through limestone as part of Western Australia’s coastal defences in World War Two. For many years the complex was abandoned and all but forgotten. The tunnels were filled with sand and debris and few people, except for some local children who discovered and played in the tunnels, even knew that the complex was there.
Although reaching a depth of 10 metres, the tunnels were not reinforced and would have given crews scant protection if they had ever come under heavy fire from warships. Initially there were 4 anti-aircraft guns located on the site and soon afterward three 5.25 inch coastal defence weapons were installed. Later still two 90cm searchlights were installed to illuminate the sea and sky at night. Gun crews either stayed in the tunnels while on duty or at an army camp in dead ground behind Buckland Hill.
Today, the Battery and tunnel complex is open every Sunday, with tours every half hour. Unless you are Northshore SES volunteer that is…
Local Manager Northshore SES Nick Elliott said “The Leighton Battery is a favourite exercise venue with our members. Northshore has developed a close relationship with Artillery WA (The Royal Australian Artillery Historical Society of WA) and the tunnels manager David Carter, and the facility has been a regular venue on our training calendar since 2009.” 
Nick added “We typically plant a number of casualties around the site, both externally as well as within the tunnels. Teams have to prepare themselves to work in the confines of the tunnels, in pitch black, and with limited room to move. Other interesting features, such as the old 5.25 inch gun mounts, provide opportunity for more challenging casualty extractions.”
The next exercise at the Battery is already being planned. I wonder what curve-ball will be thrown in by the training team for that one? Only time will tell….