Z Experimental Station The Z Experimental Station ( ZES ) , Cairns was set up in July 1942 , jointly by Secret Intelligence Australia and the Inter - Allied Services Department . The building chosen to be the headquarters was known as " Fairview " ( or House on the Hill ) , and it had been the ancestral home of the grandparents of Sir Charles Kingsford Smith . As far as ISD was concerned it was used as a wireless relay station for the New Guinea Section . The site was selected by Commander Roy Kendall , the head of SIA and was about inland from the town of Cairns , North Queensland . The site was originally chosen for its good radio reception . There were , however , good security conditions for training , until the Cairns district became a very active assembly area for Australian and US troops operating in New Guinea . Until June 42 , ISD special operations personnel were trained at the Guerilla Warfare School , Foster , but this establishment in the south of Victoria had an extremely rugged climate , which continuously resulted in sickness on the part of operatives who had lived for many years in the tropics . Since ZES was the only ISD establishment outside the headquarters in Melbourne , it became a holding establishment as well as a training school . It was set up at a time when the town of Cairns was partly evacuated , and the area was isolated from the rest of Australia . Owing to transport difficulties , many of the New Guinea operatives were delayed in Cairns after their training was completed for as much as 69 days . This worked both against security and against the morale of the operatives . When the transport arrangements had been finalised , several operations staged out of the Z Experimental Station , including the famous Operation Jaywick raid into Singapore Harbour . This was due to Cairns ' proximity to the islands in the South West Pacific Area . The Jaywick party departed Cairns near midnight 9 August 1943 in the MV Krait and sailed along the northern coast before reaching Potshot in North Western Australia which was the departure point for the Jaywick mission . Basic special operations training was undertaken at the ZES . This instruction included weapons training , minor tactics , demolitions , folboat operations , signals , codes and ciphers , first aid and unarmed combat . With the continuing influx of Allied service personnel into Cairns and with many local Cairns families returning to their homes after evacuating , the security situation for the ZES deteriorated to the extent that a new training facility had to be found . A site on Fraser Island in South East Queensland was selected and all basic Special Operations training had been transferred to the Fraser Commando School by October 1943 . In the meantime , ZES continued to be used for specialist training for Allied Intelligence Bureau ( AIB ) personnel in such subjects as jungle foods and advanced demolitions . With the liquidation of the ISD in April 1943 , the ZES was handed over to the AIB for use by the Netherlands East Indies Forces Intelligence Service , Section III ( NEFIS III ) . Operating as a field intelligence unit , NEFIS III continued to train Indonesia n operatives at ZES and use it as a staging point for operations . ZES was closed down in December , 1945 and the property disposed of by the Australian Government in 1950 .