In essence, a minesweeper deploys from the stern, cables that cut the anchor cable of the mine bringing it to the surface where it can be detonated by gunfire. Read about minesweeping in New Zealand during World War One and Two.


In Practice:

In essence, a minesweeper deploys from the stern cables that cut the anchor cable of the mine bringing it to the surface where it can be detonated by gunfire. This is why fishing trawlers were used or designs based on these types of vessels for naval service. Most minesweepers are made of wood or non-ferrous metals so they can sweep magnetic mines. This was long, boring, and dangerous work. Five volunteers lost their lives in 1941 sweeping mines in the Hauraki Gulf. Matai  had a mine lodge close under her stern which had to be removed very carefully and destroyed.

First World War:

New Zealand did not being minesweeping operations until very late in the war. Even the disappearance of a merchant ship, SS Wairuna, in June 1917 and the of sinking another, SS Port Kembla off Cook Strait in September 1917, did little to disturb New Zealand’s complacency.[1]

With the advice that mines had actually been laid around the coast two trawlers were chartered by the Government for minesweeping duties, some equipment manufactured and other necessary supplies ordered from overseas.  Sweeping of the two fields commenced in February 1918 by the trawlers Nora Niven and Simplon and continued until May 1919.  These were manned by civilian crews provided by the owners, supplemented by a small number of naval personnel from Philomel.   A supplementary sweep of the northern field, utilising a different type of sweeping gear obtained from Britain, was undertaken by the whaler Hananui II in May 1919.Although the relevant documentation does not seem to have survived, the masters of the vessels were later recognized as having been members of the New Zealand Naval Auxiliary Service.[2]

Second World War:

Unlike the experience of the First World War, New Zealand was prepared for minesweeping operations in 1939.  A large number of vessels were deployed around New Zealand to three minesweeping groups located at Auckland, Wellington and Lyttleton. The vessels included Castle-class minesweepers, trawlers, and converted merchant ships. The German raider Orion laid mines in the Hauraki Gulf that were swept by the Auckland based minesweepers. Unfortunately, HMNZS Puriri, a converted coastal cargo vessel was sunk on 14 May 1941 while sweeping these mines.

In addition to service around New Zealand, some minesweepers were sent to the Solomans Islands and Fiji to support the United States naval forces. HMNZS Matai, Gale, and Muritai served in these theatres. Minesweeping continued in New Zealand until mid 1946 when the last of the defensive mines had been cleared.

Service with the Royal Navy 

New Zealanders served with the Royal Navy aboard minesweepers in both wars. In every theatre where the Royal Navy operated, fleets of minesweepers were deployed.

The minesweeper HMS Cromarty, commanded by Lieutenant Commander C. Palmer (Auckland) through the Eighth Army’s advance along North Africa and in the Sicily landings led the first attempt to sweep the Straits of Bonifacio. Lt. Cdr Palmer recalled:

‘We were preceded by a captured Italian shallow draft sweeper. It was not long after ‘Out Sweeps’ that the Italian cut a mine. Suddenly I saw my forward lookout point ahead, turn and shout. I ordered ‘Hard a starboard’ hoping to clear the mine. We actually struck the mine at 11.23. I remember no more. I lost about 20 dead [of the ship’s company] and many others were badly injured. I spent many months indeed years in various hospitals and eventually returned to NZ by hospital ship in March 1945.’

[1]Wairuna was captured by Wolf on 2 June 1917 and Port Kembla struck a mine in the Cape Farewell field on 18 September 1917.

[2]Each of the masters was awarded the Meritorious Service Medal and the unit given in the London Gazette is the New Zealand Naval Auxiliary Service.   London Gazette dated 1 April 1919