Chirnside 1 is a very unique site. It survives in remarkably good condition beneath an old privy in the back garden of a house built high on the side of a valley. The author of this brief report was granted a rare chance to visit the site, which is on private property.
A hidden lever, buried in the ground a few feet away from the privy door, is turned 90 degrees to release the toilet bench to allow the whole structure to easily be lifted.
The dugout is accessed by a shaft beneath an old fashioned bench seat and bucket toilet, which lifts with the aid of counterbalance weights to allow entry.
One then passes through a low chamber and door into what is known as the Map Room, since it has a large table.
This is the roughly the size of an Anderson and uses similar corrugated iron sheets. A concealed door in the end wall of this room opens to allow access to the Wireless Room.
With the Map Room table and bench folded back, the far wall pivots to reveal the Radio Room behind the sleeper wall. A variety of fascinating mechanisms control access at each stage, with built in fail-safes in case of damage.
It also appears that a escape tunnel may have been started at some time in the far wall of the chamber. This does not seem to have been completed and the initial opening covered with metal sheeting.
Messages delivered to the site arrived via a special tree stump, with a top that could be moved aside to allow a split tennis ball to be dropped down a pipe concealed inside. This came out in the radio room. It suggests that there were one or more couriers who would bring messages to the site, which would be placed inside the split tennis ball.
The counter weights for the restored entrance. Note the large lead ingot at the bottom, beneath a smaller ingot and some lead sheet. The large ingot is stamped Broken Hill Australia, and appears to be from the same batch as those at Hemyock. The lead sheet is a modern addition to counterbalance the reconstructed privy box precisely.
Originally a hedge ran through the garden almost parallel to the privy. This was used to conceal a complicated and multi layered ventilation system along with the aerial feed from the trees to the radio room.
Also hidden by the hedge was the “dead letter drop”. This was disguised as a tree stump with a lid that swung around revealing a hollowed out centre and sitting on top of the message pipe leading down to the radio room.
Messages left in split tennis balls would then be rolled down to the operator. Messages would have been left by presently unknown local informants.
The aerial cable runs up the groove to the left of the bird box and can be seen curving across the trunk where it would have connected to the dipole aerial in the branches.
A brief online report cannot hope to cover all the complexities of this site, or the full details of Douglas Ingrams career with Auxiliary Units. The complete story is told in “Chirnside 1” by Hugh May. This 120 page book contains the results of an extensive investigation of all aspects of the site and is highly recommended.
Bewley Down Outstation
Chirnside 1, by Hugh May