30 Sig Regt used the prison as accommodation during an exercise in the later half of the 1970's. We were practicing long range HF radio communications using the E-21 set. I recall the old rifle range being used as the transmitter site; it was the only flat piece of land capable of suporting an 80ft mast and 500 feet of copper cable that we used as the transmit antenna. I also remember RCT personnel ferrying us to and from Kowloon side. Fond memories of a time before the cold war ended and deploying overseas was more likely to mean an exercise than an operation.