At the entrance to the Room
Me in the Plotting Room

It’s a bit humid in here!


Faber Fire Command. Post-war Photo

Underground on Mount Faber are several concrete lined rooms. They are not really particularly well known, but they have often been visited by the inquisitive/explorers, to whom the location is well known. These rooms are sometimes referred to as being bunkers. However, this is incorrect. This subterranean complex, built in 1936, was an integral and important part of Faber Fire Command. Its title was the Fortress Plotting Room.

A Fortress Plotting Room was where information from Fortress Observation Posts was received, plotted and the required information extracted and then acted on. There were two Fortress Plotting Rooms in Singapore. The other was part of Changi Fire Command. Counter bombardment gun batteries each had a Battery Plotting Room, which received information from the relevant Fortress Plotting Room. Another Plotting Room was in the Combined Battle HQ at Fort Canning.

The counter bombardment batteries were; Johore & Buona Vista 15-Inch Batteries, Connaught & Tekong 9·2-Inch Batteries, and the Sphinx 6-Inch Battery. The remaining gun batteries were classed as Close Defence Batteries, and as such did not require plotting rooms.

In Penang, there were plotting rooms for the Batu Maung and Auchry Batteries.

Fortress Plotting Rooms contained a Range-finding Exchange (telephone), Fortress Plotters to track shipping targets on charts, Fall-of-Shot Indicators, Fire Direction Table, Ballistic Correction Calculator and other equipment to collate incoming information about the range, speed and course of targets.

Gallery

Plotting Room
Members of the Australian Women’s Army Service working at the Plotting Table
North Head, Sydney Fortress Area

Plotting room
Members of the Australian Women’s Army Service working in the Plotting Room
North Head, Sydney Fortress Area

Australian coast defences made extensive use of the women’s services to man the plotting rooks and observation posts. This released men for service elsewhere.

Fall of Shot Encoder
A Fall of Shot Encoder

The Fall of Shot Encoder enabled the Fortress Plotting Room to take fall of shot observations from two Fortress Observation Posts and convert them into Clock Code.

Faber Fortress Plotting Room had two Fortress Plotters. Plotting rooms had their own telephone exchanges to enable rapid communications to the Fire Command, Observation Posts etc. The telephone switchboard was not enclosed or in a separate room. This allowed the Plotting Officer in the Plotting Room to supervise all connections made. People staffing the plotting room would wear a head and breast telephone, the ‘hands-free’ of the day.

Which Plotting Rooms Remain?

Faber and Connaught plotting rooms certainly still exist. A third existing is in the Combined Battle HQ at Fort Canning.

Buona Vista Battery Plotting Room: Almost certainly there in the KINS Camp. The entrance is sealed off.

Changi F.C. Plotting Room: Almost certainly remains hidden in Changi Air Base on Changi Hill, between the masts and the golf club to the west.

Johore Battery Plotting Room: I've never managed to get an accurate fix for this, but if my thoughts about location are correct, it still may be there.

Sphinx Battery Plotting Room: Possibly destroyed by building work.

Tekong Plotting Room: More than likely still exists some 400 metres north of the No.1 Gun Position.

Other Batteries
& Defences