Minesweepers of the Royal New Zealand Navy


Commissioned minesweepers and danlayers of the Royal New Zealand Navy from its formation on 1 October 1941 to the present. The RNZN was created two years into World War II. For coherence this article covers the war years from the start, and thus includes also the New Zealand minesweepers operating from the beginning of the war.

World War II minesweepers

During World War II the RNZN operated 39 minesweepers and danlayers. This included 20 naval trawlers, 5 converted trawlers, 10 converted merchant boats and 4 danlayers.

Naval trawlers

s were trawlers purpose built to Admiralty specification to operate as minesweepers and/or anti-submarine boats.

Castle class

Thirteen naval trawlers were commissioned. Apart from James Cosgrove and Wakakura, all were built in New Zealand by government directive, circa 1942. They were long, displaced 540 tons standard or 612 tons loaded, and were designed for a complement of 27. The three-cylinder engine of from A & G Price of Thames gave a speed of. The coal-fired boiler was of the Scotch marine type. The boiler size governed the size of ship that could be manufactured, and as boiler plate of the required size was not available, two completed boilers and some partly completed boilers were supplied from Britain.
NamePndBuilderDatesCareerFate
HMNZS ArohaT24Stevenson & Cook, Port Chalmers1943–1945Served at Auckland
HMNZS AwatereT25Patent Slip, Wellington1943–1945Served at Wellington
HMNZS HautapuT26Stevenson & Cook, Port Chalmers1943–1947Served in Lytteton
HMNZS HinauT17Senior Foundry Co., Auckland1942–1945LL Flotilla AS
HMNZS James CosgroveT101941–1944
HMNZS MaimaiT27Stevenson & Cook, Port Chalmers1943–1946Served at Wellington
HMNZS ManukaT19Mason Bros, Auckland1942–1945LL Flotilla AS
HMNZS PahauT28Stevenson & Cook, Port Chalmers1944–1945Served in Wellington
HMNZS RimuT18Seager Bros Shipbuilders Ltd1942–1945LL Flotilla AS
HMNZS WaihoT34Stevenson & Cook, Port Chalmers1944–1946Served in AucklandSold to Red Funnel trawlers
HMNZS WaimaT33Stevenson & Cook, Port Chalmers1944–1946Served in LyttetonSold to Red Funnel trawlers
HMNZS WaipuT32Stevenson & Cook, Port Chalmers1943–1946Served in Auckland
HMNZS WakakuraT001941–19471926–1941 was HMS Wakakura in the New Zealand Division of the Royal Navy. Used as danlayer from July 1944.

In addition two further Castle trawlers, Tawhai and Waikato, were completed in 1946 but were not commissioned.

Bird class

The naval trawlers were long, displaced 923 tons full load, and could manage. They had a complement of 33–35 and were armed with one gun, two Hotchkiss guns in single mounts, twin Lewis guns and 40 depth charges. They were equipped with asdic.
NameDatesCareerNotes
1941–1946
1948–1949
1951–1956		AS MS
Training ship
Training ship
1941–1943AS MSSunk by enemy aircraft on 7 April 1943 near Tulagi Harbour in the Solomon Islands. Five crew men were lost.
1941–1946
1952–1955
1956–1967		AS MS
Training ship
Research ship		On 19 August 1943 Tui and some US Kingfisher floatplanes jointly sank the.

Isles class

The naval trawlers were long, displaced 740 tons full load, and could manage. They had a complement of 40 and were armed with one 12-pounder gun, three 20 mm Oerlikons in single mounts and depth charges.
NameDatesCareerFate
HMNZS Inchkeith 1941–1946
HMNZS Killegray 1941–1946
HMNZS Sanda 1941–1946
HMNZS Scarba 1941–1946

Other types

Converted trawlers

These vessels were usually armed with a quick-firing 4-inch or 3-inch gun on a raised bow platform, some machine guns, and depth charges. Vessels used for minesweeping were also fitted with minesweeping and mine handling equipment.
NameDatesCareerFate
HMNZS Futurist 1941–1944Functioned as a boom gate vessel 1944
HMNZS Humphrey 1941–1944
HMNZS Kapuni 1941–1945Functioned as supply ship 1945
HMNZS South Sea 1941–1942Previously HMT Ferriby of the Royal Navy, launched as a civilian trawler in 1913. Sunk 19 December 1942 in collision with inter-island ferry Wahine in Wellington Harbour
HMNZS Thomas Currell 1941–1944Functioned throughout World War II as a minesweeper vessel.Currently beached and deteriorating on the coast of Chatham Island.

Converted merchant boats

These ships were usually armed with a quick-firing 4-inch gun, machine guns and autocannon. Vessels used for minesweeping were also equipped with the appropriate equipment.
NameDatesCareerFate
HMNZS Breeze 1942–1944
HMNZS Duchess 1940–1945examination vessel 1942–45
liberty launch 1945		abandoned at wreck bay Rangitoto Island
HMNZS Gale 1941–1944
HMNZS Hawea 1941–1945Functioned as supply ship in 1945.
HMNZS Kapuni 1941–1945Functioned as patrol boat 1940 and supply ship 1944–45.
HMNZS Matai 1941–1946Functioned as transport ship 1945–1946.
HMNZS Muritai 1941–1946Functioned as training and cable-lifting ship 1945–1946.
HMS Puriri 1941Puriri was sunk just before the creation of the RNZN.14 May 1941 struck a German mine NE of the Whangarei heads and sunk with the loss of 5 crew members.
HMNZS Rata 1941–1943
HMNZS Viti 1941–1945

Danlayers

COMSOPAC

COMSOPAC is an acronym for Commander South Pacific. During World War II, one of the major United States theatre commands was the command of the South Pacific Area. This command was usually referred to as COMSOPAC
It was formed in April 1942 as a subordinate command of Pacific Ocean Areas, commanded by Robert L. Ghormley through October 1942, William Halsey, Jr. to June 1944, John H. Newton to March 1945, and William L. Calhoun to the end of the war.
In June 1942 New Zealand passed the operational control of most of its South Pacific naval forces to COMSOPAC. This continued until COMSOPAC released control in June 1945.
The headquarters for COMSOPAC were initially located in Auckland, New Zealand. In July 1942 they were transferred to Nouméa, New Caledonia,

The 25th Minesweeping Flotilla

In the early months of World War II the New Zealand minesweepers had no formal grouping as a flotilla Then Niagra was sunk in June 1940. On 18 July 1940 the Naval Board designated the First Group for coastal minesweeping, and allocated Port minesweepers to the main ports. They were:
;First Group
;Port Minesweepers
On 14 November 1940, a few weeks after the founding of the Royal New Zealand Navy, they were reorganised as the
First Minesweeping Flotilla
;First Group
;Port Minesweepers
Then on 23 December 1940 the Port minesweepers were separated, and the remaining minesweepers were organised into the 25th Minesweeping Flotilla. This name aligned with the flotilla names used by the Royal Navy. The makeup of this flotilla changed during the course of the war, as new minesweepers were commissioned, others sunk or withdrawn for repairs or refitting, and requirements changed.
Here is a snapshot of the 25th Minesweeping Flotilla on 27 March 1943:
;7th Trawler Group – Auckland
;30th Trawler Group
;194th Auxiliary Minesweeping Group – Auckland
;94th Auxiliary Minesweeping Group – Auckland
;95th Auxiliary Minesweeping Group – Wellington
;96th Auxiliary Minesweeping Group
The Port minesweepers were organised into their own flotillas. Eleven new Castle-class minesweepers joined the Port flotillas on completion, 1943–1944.

Post war

Ton class

The RNZN operated two minesweepers on anti-infiltration patrols in Malaysian coastal waters during 1966 and 1967.
They are the only commissioned RNZN ships never to have visited NZ.
NameDatesCareerFate
1965–19661967 sold to Argentina and renamed ARA Chubat
1965–19661967 sold to Argentina and renamed ARA Neuquen

These Admiralty designed coastal minesweepers were built with composite hulls of wood on aluminium frames and a minimum of magnetic material in the hull. They were intended to meet the threat of seabed mines laid in shallow coastal waters. Their shallow draft gave them some protection against pressure and contact mines, and allowed them to navigate in shallow inshore waters. They were long, displaced 360 tons standard, could manage, and had a complement of 32. They were named after British villages which ended with "ton".
Early in 1965 Indonesia was employing a policy of confrontation against Malaysia. New Zealand agreed to assist Malaysia by deploying two Royal Navy minesweepers then in reserve at Singapore. These were commissioned into the RNZN on 10 April 1965 and joined the Royal Navy's 11th Minesweeping Squadron, taking part in anti-infiltration patrols in Malaysian waters.
In their first year they carried out 200 patrols, with 20 incidents involving intruding Indonesians, often taking as prisoners those aboard intercepting small craft. By the time the Indonesian confrontation policy ended in August 1966 Hickleton and Santon had jointly steamed.