 They were partitioned internally with fibrous-cement sheeting to provide equipment, power and battery rooms, and living accommodation for two or three maintenance staff.It is thought that these buildings were designed and pre-fabricated in one of the PMG's workshops in Melbourne, Adelaide or Sydney.Due to the impossibility of obtaining carrier telegraph equipment from overseas during the war years, the PMG's Melbourne workshops manufactured and assembled a prototype four-channel VF telegraph (Type R), which was in design early in 1942, and intended principally for use by the Army Signals Corps in forward areas and for combat use in New Guinea and the Pacific.