Whangaparaoa Tunnels

During the Second World War the Whangaparaoa Peninsula was the largest concentrated area of coast defence activity in New Zealand. Apart from the batteries, there were two RNZN sites that controlled the degaussing range and an observation post for the controlled minefield that was laid across the Whangaparaoa Passage.

 

During the Second World War the Whangaparaoa Peninsula was the largest concentrated area of coast defence activity in New Zealand. Apart from the batteries, there were two RNZN sites that controlled the degaussing range and an observation post for the controlled minefield that was laid across the Whangaparaoa Passage.[1] What follows is a history of the tunnels and positions that were constructed by the Army during the war for coastal defences.

 The 9.2-inch battery

In 1921, a consideration of New Zealand’s coastal defences identified Whangaparaoa as a potential site for location of coastal batteries including large calibre guns. Due to the limited budgets and the Depression, no actual work was carried out until the outbreak of the Second World War. Before the war, the 6-inch battery was constructed as an interim measure by 1941. Work on the 9.2-inch battery did not commence until late 1942, long after any direct threat from Japanese naval forces.[2] The battery was supposed to have three 9.2-inch MK XV land service guns on Mk IX 35° mountings with a gunshield.[3] Only two guns were emplaced. Only one gun was operational by the end of the war in September 1945.[4]

The fact that there are tunnels at Whangaparaoa was due to combination of cost and the local geology. When the 9.2-inch gun battery was being constructed during the Second World War, it required a burster-slab, a piece of reinforced concrete that protected the battery from air bursts or direct hits from return fire. This could not be made due to the lack of manpower and materials. However, the local rock formations of weathered greywacke made tunnelling a viable alternative. There were plans on hand supplied from Britain that showed how to build coastal defences and supporting tunnels. Tunnelling had the advantage of reducing the amount of materials needed for construction, always a consideration in wartime New Zealand. Because the rock did not need propping after excavation, forms could be put in and concrete poured in to line the tunnel.

It was decided that the emplacements, engine room[5], and plotting room would be widely dispersed in the position connected by long tunnels. This would enable the battery to be a self-contained complex with communication cables being run along the tunnels. This tunnel feature made the 9.2-inch battery at Whangaparaoa unique amongst the three batteries that were constructed during the Second World War. The other benefit was to the crew of the guns. If the tunnels were deep enough, then there was no need for any burster-slab. This meant that most of the battery was underground. All that could be seen on the surface were the emplacements for the 9.2-inch guns and the tunnel entrances. Because of wartime security, this position was known as A-1.

An access road was made running from the 6-inch battery and Shakespeare Bay to the new site. When the tunnels were constructed it was worked out that they had to be a minimum of 40ft [12m] deep. This would eliminate the need for the burster-slab. Additional cambers were built for the storage of fuel oil for the engine room and storage for equipment to maintain the guns. To design the tunnels, the Public Works Department whose responsibility it was to build the position, referred to tunnel designs used by the New Zealand Railways for personnel tunnels. As construction was undertaken, a lift for personnel and material was eliminated due to cost. But stairs and blast traps were added to the tunnels. There were many issues following the construction. Drainage became a problem in the winter following the construction and the drainage system had to be reconstructed. Because limited consideration had been given for the installation of heavy equipment, openings and temporary tunnels were dug to bring in the equipment then backfilled. Personnel shelters that were supposed to be located next to the tunnel entrances for the protection of personnel from attack were set far away from the entrances. An author on the coastal defences of Whangaparaoa calls this an “example of ‘Kiwi-do-it-yourself’ in action.”[6] Overall 592m of tunnels were built by the Public Works Department along with 188m of stairways all lined with concrete. This required the removing of 10,000 cubic metres of spoil.

The tunnels were constructed through to May 1943. For example by March 1943 two of the magazines were completed, and the other parts including the connecting tunnels almost 50% completed. The three magazines were designed to store 140 armour-piercing rounds in one, 95 high-explosive in the second and 40 practice rounds in the third. Because of the weight of the shells, a trolley and rail system was put in so the gun crew could move the shells to the guns from the magazines and then use the hoist to put the shell in the breech. By the end of 1943, the 28 tonne barrels, the heaviest part of the battery were ready to be installed.[7] However by this time the cost and the futility of the construction were obvious even to those in government. The Army argued that because the work had been started, it was not cost effective to suspend work. The War Cabinet agreed but cancelled the third gun that was planned for the battery. In 1944 outlying spotting positions and a direction finding radar that were supposed to support the battery were not built. This effectively limited the range and ability of the battery to see targets and range properly. In some ways this battery was now no more effective that the batteries of the 19th century that had been installed at North Head.[8]

The battery was finished in 1945. In March 1945 No. 3 gun fired its first proof round followed by No. 2 gun first proof round in November 1946. During this period the engine rooms, magazines, and plotting rooms were finally completed by July 1946. The final cost of the battery was approximately £500,000, a huge amount for the time. The construction cost alone was £339,861.[9] The battery was placed in reserve and became Auckland’s only long range battery. In 1947 it was decided that training on these guns would be carried out at Whangaparaoa[10] and the only live-firing exercises were carried out at this battery with the last in 1951. The cost of maintenance was too excessive for this battery and by 1953 it was closed down.[11] The engines were dismantled, the ammunition removed, and it was looked after by a caretaker with an annual maintenance programme initiated.[12]

In 1957, the Royal New Zealand Navy thought that this site would be very useful for gunnery training and storage of ammunition.[13] In early 1960 the government transferred control from the Army the RNZN and it became a naval armament depot. The guns were scrapped in 1960.[14] Changes were made to the rooms and tunnels and an air-conditioning unit installed. By 1997 the engine room was stilled being used as a storage facility for naval ammunition.[15] The ordnance store is the only remaining example in New Zealand along with the miniature range, one of only two ever built in New Zealand. The war shelters were never used after the transfer by the Army and the gun pits were securely fenced off within the site.[16] The RNZN maintains the tunnels as part of its responsibility for the site.

The 6-inch gun battery

Because of the delay in construction of the 9.2-inch battery, two Mk VII 6-inch guns on 15° C.P. II mountings were transferred from North Head to a position located on a spur running down to Huroa Point. This would serve two purposes. It would cover the Whangaparaoa Passage, and cover the sea east of Tiritiri Matangi Island. The design was the same as used at North Head but because it was supposed only to be a temporary measure it was decided to dispense with reinforced concrete and use the tunnelling method that was to be used for the 9.2-inch battery. This was the first battery to be built in New Zealand using this method. There were to be two levels below the gun pits. The first would be the magazines; the lower level was the engine rooms, plotting rooms, and a radio room. Behind the magazines were positions for the crew, first aid post, officer’s rooms and a toilet. The Battery Command position was located centrally and behind the two gun emplacements. From there a set of stairs led to a tunnel that led to the rear and an access road to the camp for the garrison. This was not a popular camp because in the 1940s it was some way from Auckland and known as wet and muddy in wintertime.[17] In this lower access tunnel, the plotting rooms, engine room, telephone exchange, artillery stores and a workshop were located along the tunnel leading to the exit.[18] Another position was constructed for searchlights to cover the Whangaparaoa Passage.[19] This included tunnels to connect the searchlights to an engine and generator rooms. By July 1942 this position was nearly constructed and was finished in early 1943 but again it was far too late to be of any practical use. It cost the government £344,411 to construct and equip.[20] In 1942 two 40mm Bofors guns were emplaced for anti-aircraft defence.[21]

A year later it was placed into reserve. In 1950 the guns were removed back to North Head for training. The site was abandoned and all material stripped out and reused elsewhere. The searchlights were also removed at this time. In 1959 the RNZN mounted a 4-inch Mk IX gun with gunshield taken from the Loch-class frigate HMNZS Kaniere when she was decommissioned in the left emplacement for training. However the ‘frying-pan’ cover for the emplacement had to be removed by a controlled explosion.[22] This gun remained in use until 1967 when it was decommissioned and sent to MOTAT.[23]

One part that was used for both batteries was the radar. By late 1941 a radar set was installed at some distance away from the 6-inch battery. This was taken over for use by the 9.2-inch battery when the 6-inch battery was closed down. However, without the complete set of radars that were supposed to be installed, it had limited coverage, reducing its effectiveness as a method of acquiring and plotting targets.[24]

This area of the Whangaparaoa Peninsula has remained in Defence hands until the present day and there is no present indication that it will be sold off. Currently, the old battery sites are used for training including the 6-inch battery that the SAS has used for special training. The RNZN now controls the site and it is used for small-arms training and other exercises for new recruits and midshipmen. The battery camp was retained and is still in use as accommodation.[25]

Other sites that had tunnels built were

  • plotting room for the battery on Motutapu Island
  • third magazine and plotting rooms at Palmer Head, Wellington
  • third magazine at Godley Head, Lyttleton

In 1945 a decision was made that the land east of the tank trap dug on private land would be handed over to the military[26] and has remained in defence control until the present day. The batteries at Whangaparaoa were an unnecessary cost on the Government during wartime and should have been stopped. Any threat was removed even before they were finished. The legacy however has been useful to both the Army and the Navy. Land was available for training which it is still in use today. Ammunition can be stored in the magazines which remain as safe as when they were built. In 2012, to consider building a camp, magazines and ranges would be prohibitively expensive to the NZDF budget. Fortunately then, we have to thank those officials and officers who, in a time of war, persisted with this construction irrespective of its obsolescence.

 

Bibliography

Cooke, Peter, Defending New Zealand: Ramparts on the Sea 1840-1950s Volume 2, Wellington: Defence of New Zealand Study Group, 2007, pp. 502-504.

Corbett, Peter D., A First Class Defended Port: The History of the Coast Defences of Auckland, Its Harbour and Approaches, Auckland Conservancy Historic Resource Series No. 17, Auckland: Department of Conservation, July 2003

_______________, ‘Coast Defences of New Zealand 1924-1945’, Paper given at the Department of Conservation’s New Zealand Coast Defence Heritage National Workshop, Wellington, April 1997.

_______________, World War II Defences at Stony Batter (Waiheke Island) and Whangaparaoa: 9.2-inch Counter-Bombardment Batteries A-1 and A-2, Auckland Conservancy Historic Resource Series No. 14, Auckland: Department of Conservation, December 1996.

Glackin, Russell, In Defence of Our Land: A Tour of New Zealand’s Historic Harbour Forts, Auckland: Penguin, 2009.

[1] Peter D. Corbett, A First Class Defended Port: The History of the Coast Defences of Auckland, Its Harbour and Approaches, Auckland Conservancy Historic Resource Series No. 17, Auckland: Department of Conservation, July 2003, p. 119.

[2] ibid. p. 75. Such was the case with most of the coastal defences built in New Zealand during the Second World War. After the Battle of the Coral Sea in May 1942 followed by the Battle of Midway in June, the naval threat to Australia and New Zealand was eliminated. We were in fact building guns to protect us from an enemy that would never arrive off our coasts. Due to the development of aircraft and carriers, our coastal defence batteries were obsolescent as soon as they were built.

[3] The guns were too large and heavy for a turret mounting. Additionally, such a turret would have required more machinery space to hold the engines to move the turret. If they had been fixed in positions, they would have needed less machinery than was installed.

[4] Peter D. Corbett, ‘Coast Defences of New Zealand 1924-1945’, Paper given at the Department of Conservation’s New Zealand Coast Defence Heritage National Workshop, Wellington, April 1997, p. 9.

[5] Because of the size of the guns and their mountings, it required an engine to traverse the guns to the direction of fire that was plotted by the battery personnel in the plotting room. Generators provided electricity for the battery.

[6] Peter D. Corbett, A First Class Defended Port: The History of the Coast Defences of Auckland, Its Harbour and Approaches, Auckland Conservancy Historic Resource Series No. 17, Auckland: Department of Conservation, July 2003, p. 64

[7] ibid., p. 76.

[8] ibid., pp. 76-77. See also Peter D. Corbett, World War II Defences at Stony Batter (Waiheke Island) and Whangaparaoa: 9.2-inch Counter-Bombardment Batteries A-1 and A-2, Auckland Conservancy Historic Resource Series No. 14, Auckland: Department of Conservation, December 1996, p. 38.

[9] Peter D. Corbett, A First Class Defended Port: The History of the Coast Defences of Auckland, Its Harbour and Approaches, Auckland Conservancy Historic Resource Series No. 17, Auckland: Department of Conservation, July 2003, p. 77.

[10] Peter D. Corbett, World War II Defences at Stony Batter (Waiheke Island) and Whangaparaoa: 9.2-inch Counter-Bombardment Batteries A-1 and A-2, Auckland Conservancy Historic Resource Series No. 14, Auckland: Department of Conservation, December 1996, p. 57.

[11] ibid., p. 59.

[12] Peter D. Corbett, A First Class Defended Port: The History of the Coast Defences of Auckland, Its Harbour and Approaches, Auckland Conservancy Historic Resource Series No. 17, Auckland: Department of Conservation, July 2003, pp.77-78.

[13] Peter D. Corbett, World War II Defences at Stony Batter (Waiheke Island) and Whangaparaoa: 9.2-inch Counter-Bombardment Batteries A-1 and A-2, Auckland Conservancy Historic Resource Series No. 14, Auckland: Department of Conservation, December 1996, p. 60.

[14] Russel Glackin, In Defence of Our Land: A Tour of New Zealand’s Historic Harbour Forts, Auckland: Penguin, 2009, p.96.

[15] Peter D. Corbett, A First Class Defended Port: The History of the Coast Defences of Auckland, Its Harbour and Approaches, Auckland Conservancy Historic Resource Series No. 17, Auckland: Department of Conservation, July 2003, p.71.

[16] ibid., pp. 78-79

[17] Peter Cooke, Defending New Zealand: Ramparts on the Sea 1840-1950s Volume 2, Wellington: Defence of New Zealand Study Group, 2007, p. 503.

[18] Peter D. Corbett, A First Class Defended Port: The History of the Coast Defences of Auckland, Its Harbour and Approaches, Auckland Conservancy Historic Resource Series No. 17, Auckland: Department of Conservation, July 2003, p. 118.

[19] ibid., p. 115.

[20] Peter Cooke, Defending New Zealand: Ramparts on the Sea 1840-1950s Volume 2, Wellington: Defence of New Zealand Study Group, 2007, p. 502.

[21] ibid., p. 502

[22] ibid., p. 503.

[23] Peter D. Corbett, A First Class Defended Port: The History of the Coast Defences of Auckland, Its Harbour and Approaches, Auckland Conservancy Historic Resource Series No. 17, Auckland: Department of Conservation, July 2003, p. 118.

  1. 119. See also Cooke, p. 503. This gun is now held at the Torpedo Bay museum and has been refurbished.

[24] ibid., p. 146.

[25] ibid., p. 119.

[26] Peter Cooke, Defending New Zealand: Ramparts on the Sea 1840-1950s Volume 2, Wellington: Defence of New Zealand Study Group, 2007, p. 503.