Secret fuel bunker
During World War II and the threat of a Japanese invasion in the South Pacific, efforts to defend New Zealand were increased. In 1942, Cambridge was chosen as a suitable location for a secret aviation fuel depot called Aviation Reserve 9 (AR9).
The concrete pump house and the large depression at the top of the hill in the parklands around Lake Te Koo Utu are all that remain of the depot. The fuel tank was emptied in 1946 and removed in 1950. In the 1970s the pump house was sealed. Recently it has been restored so that you can visit the site and see inside the bunker.
Hidden in the hill
1) The railway yard was at the top of the hill, and the first fuel delivery arrived by rail on 27 August 1942. Up to 11 rail tank cars of fuel arrived every week.
2) A 600,000 gallon (2.7 million litre) fuel tank was installed at the top of the hill. Despite being sunk in a 60 foot (18 metre) deep hole, with a top diameter of 130 feet (40 metres) and a bottom diameter of 72 feet (22 metres) the tank was hard to hide, so gum trees and other fast-growing vegetation were planted for camouflage.
3) This concrete structure was the pump house. Fuel from the tank was pumped to trucks waiting below (where the carpark is today). Look inside the pump house and you will see a tunnel entrance on the left. This tunnel ran back to the fuel tank and contained the fuel pipe line.
4) Trucks took the fuel to Royal New Zealand Air Force sites, including the RNZAF Station Rukuhia, known as No.1 Repair Depot (now Hamilton Airport). Large aircraft overhauls, conversions and repairs were facilitated at Rukuhia and fuel was needed for test flights.
The night tragedy struck
In its early days the fuel tank suffered two serious leaks, but the worst incident by far was a tragedy that struck in the early hours of 14 October 1943.
The bad news was described in this brief communication on that day:
Four huts AR9 destroyed by fire approx 0330 hours this morning. Damage approx 400. Cause believed cigarette. One casualty already notified'
Cambridge Police Constables H.C. Maisey and F. Solly searched the ruins and found the charred body of LAC Richard Edward Isaacs, NZ423975.
Dispelling the myths
Perhaps because of the secrecy and security surrounding the fuel depot, locals have forgotten, or maybe never knew, the true purpose of this site.
Rumours suggested the pump house was a bomb shelter and that the tunnel ran all the way to the town hall to provide an escape route for the mayor during an air raid. Some said the tunnels were part of a maze of secret passageways used during the war.
Neither of these stories are true. The tunnel ran only a short distance, through the hillside to the fuel tank.
In 2018, as a Cambridge Community Board project, the concrete seal on the front of this pump house was replaced with grills, so people could see inside.
This was made possible with the generous assistance of C & R Developments, Waipa Civil, Merv Cronin and Dave Homewood.
Take a visit to Lake Te Koo Utu and see the fuel bunker for yourself!
The National Archives: Accommodation and Works Services - Airfuel Reserve Depot - (AR9) Cambridge, AIR1W1651 82 (R10860399) and AIR1W1651 83 (R10860400).
Aircraft Photo: RNZAF Official
Aerial Photo: 6 June 1943, RNZAF Official