The Green Street bunker at West End (Townsville), Queensland, Australia is also known as the Sidney Street bunker and Project 81. It was built by the Royal Australian Air Force during World War II. The erection of the Green Street bunker (Project 81) at the end of Sidney Street in West End was approved on 12 March 1942. The road up Castle Hill was closed to traffic on about 12 March 1942 to ensure the construction of military facilities such as this bunker were not obvious. The bunker was completed about 12 weeks later. The bunker was fully air-conditioned during its use in World War II. Buildings/rooms There were 17 buildings at Project 81 as follows:- 1 Guard Room 2 Old dilapidated weather board cottage, Airmens Quarters 3 Prefabricated Hut G.I. Roof - Met Store Room 4 Latrine 5 G.I. Shed 6 Weather board Building G.I. Roof General Offices 7 Canteen 8 W.A.A.F. Mess Room 9 Airman's Mess Room 10 Guard House 11 Latrines 12 Air Conditioning Plant 13 Area Operations Room and General Offices 14 Photographic Intelligence Section 15 G.I. Shed 16 Weather Board Building G.I. Room 17 25 Yard Range Mound It is believed that the bunker was used as No. 24 Squadron RAAF Headquarters and by the RAAF Operations and Signals group (Intelligence). The building (120 ft x 60 ft) was built like a fortress, with enormous thick walls and roof. It was apparently capable of sustaining a direct hit with minimal damage. The rooms in the bunkers were used as follows:- Emergency Power Plant Intelligence Officer Meteorological Officer Meteorological Room Navigation Officer Crew Room Operations Room Cypher Room Signals Office Receiving Room Signals Officer Men's Lavatory Telephone Exchange Strong Room Two other rooms separated by a walkway were:- Fan Room Condenser Room Construction 600 cubic yards of concrete and 50 tons of reinforcing steel was used to construct the Green Street bunker. Four timber buildings were located nearby and one was located on top of the bunker to give it the appearance of a domestic residence from an enemy aerial view. The bunker was well camouflaged and camouflage netting would have been attached from the roofline of the bunker. The bunker also had its own very large electricity generating plant. A small separate building at the end of the bunker and adjacent to the Generator room, housed the air conditioning plant. It had a sunken floor