- Yes - In the Tech Tree.
- Yes - Event/BP.
- Yes - Premium.
- No - I would not like to see the NZ HDMLs/SDMLs in game.
Q1189 on trials in Wellington before her armament conversion in 1943
Description:
New Zealand’s use of the Harbour Defense Motor Launch, stems from the need for local ASW and AA patrols in small local harbours and ports, as the local shipbuilding yards were then full with orders for the Castle-class minesweepers, these new HDMLs would have to be imported. For ease of logistics, it was chosen to supply most of them from the US, with 22 from the US, and 10 from the UK.
They were to be standard HDMLs, with no modifications. Initially 22 were ordered in January 1942, however, it was found that the last six were not needed upon their arrival in Auckland in October 1943, and were sent to the RAN.
They would provide not only harbour patrols, but also fisheries protection duties, a role in which requisitioned civilian vessels would be used in other navies. This would allow for these civilian vessels to keep trading and operating under their owners, assisting local economies.
Q1183 at Auckland early 1944, before she would move to Dunedin.
History:
As they were small vessels, they would not survive the heavy seas on the journey from the US and UK to NZ, as such they would be transported on mercantile vessels, as cargo. They would arrive in lots as they were built. The first vessel to be shipped, the Q1090, would be lost during shipping, as the vessel it was stowed aboard, the Port Hunter was sunk via torpedo by U-582.
The US built vessels would be delivered with a 20mm aft and two .50 water-cooled browning forward, while the British Built vessels would be delivered with the same 20mm cannon, but two .303 Vickers instead of the brownings. The Vickers guns would be swapped with .50 brownings before the vessels would commission, giving a uniform armament.
| HDMLS | Builder | Merchant ship | Arrival area | ||
|---|---|---|---|---|---|
| Q1183-1184 | Maden & Lewis Co | SS Frank Joseph Irwin | Wellington, January 1943 | ||
| Q1185-1186 | Maden & Lewis Co | SS Pere Marquette | Wellington, March 1943 | ||
| Q1187-1190 | Everett Marine Ways Inc | SS Kootenay Park | Wellington, April 1943 | ||
| Q1191-1194 | Gray Harbour Ship Building Co | SS Mount Robinson Park | Auckland, August 1943 | ||
| Q1348-1351 | Ackerman Boat Works | SS Mount Robinson Park | Auckland, February 1944 |
Upon arrival, they would be unloaded and immediately sent for commissioning trails. Some vessels would be delivered to Lyttleton, as it was intended to have a group of vessels there, however with the war improving, they would move to Auckland with the 124th as to improve that group’s numbers a few weeks after they were initially delivered. They were allocated as follows,
| 124th ML Flotilla, Auckland | 125th ML Flotilla, Wellington | ||
|---|---|---|---|
| Q1183 (Until 1944) | Q1183 (From 1944) | ||
| Q1184 (Until 1944) | Q1187 (From 1943) | ||
| Q1185 | Q1188 | ||
| Q1186 | Q1189 | ||
| Q1187 | Q1190 | ||
| Q1191 (Until 1944) | Q1191 (From 1944) | ||
| Q1192 | Q1349 (From 1944) | ||
| Q1193 | |||
| Q1194 | |||
| Q1348 (Until 1944) | |||
| Q1349 (Until 1944) | |||
| Q1350 | |||
| Q1351 |
Their service during the Second World War would be uninteresting, serving within their allocated Flotilla’s patrol areas for the duration of their service, seeing no combat whatsoever, albeit with one small exception, as Q1186 dropped depth charges off Cape Brett on an ASDIC contact, however no submarine was proven to be in this area, with the contact most likely being a whale.
Three vessels would serve outside of the main Flotillas at Auckland or Wellington, these being the Q1183, Q1184, and Q1348. The Q1183 would be transferred from the 124th out of Auckland to Dunedin in July 1944, and the Q1184 and 1348 would serve in Fiji, with the Q1184 operating there from July to December 1944 when she was withdrawn and replaced by the Q1348, which would remain there until November 1945.
By March 1945, six vessels would depart for Manus Island, Papua New Guinea as to be a part of the British Pacific Fleet, however by May they would be released from service within this group, as they were no longer needed. They would return to their ports and duties. The vessels would begin decommissioning from June 1945, mostly at HMNZS Philomel.
These vessels would be kept in reserve, apart from Q1186, 1189, 1351, which were sold as excess to civilians as private vessels, as they were the most worn.
Q1189 post armament conversion, still in Wellington
By late 1946, the RNZN was asked to support the Department of Marine Fisheries patrols for illegal fishing and other activities. For this the extra HDMLs were recommissioned, with an altered armament of a single 20mm Cannon, (only mounted astern when needed, otherwise below deck). They would be assigned new names instead of their old Q numbers and be fully commissioned into the RNZN.
During this time, HMNZS Manga (former Q1185), would be transferred to the NZ Army, and renamed Bombardier as a target tower and general transport craft. She would remain in this duty until 1965, when she would be returned to the RNZN’s HDML fleet.
| Original Number | New Name | New Pennant | ||
|---|---|---|---|---|
| Q1183 | HMNZS Mako | P3551 | ||
| Q1184 | HMNZS Paea | P3552 | ||
| Q1185 | HMNZS Manga | P3567 | ||
| Q1187 | HMNZS Tarapunga | P3566B | ||
| Q1188 | HMNZS Takapu | P3556A | ||
| Q1190 | HMNZS Olphert | P3562 | ||
| Q1191 | HMNZS Kahwai | P3553 | ||
| Q1192 | HMNZS Maroro | P3554 | ||
| Q1193 | HMNZS Tamure | P3555 | ||
| Q1194 | HMNZS Ngapona | P3561 | ||
| Q1348 | HMNZS Pegasus | P3563 | ||
| Q1349 | HMNZS Haku | P3565 | ||
| Q1350 | HMNZS Toroa | P3564 |
These duties would be mostly calm, however due to extreme weather conditions and green crews (as they would be used to train new helmsmen), many would be wrecked or damaged, however only the HMNZS Ngapona would be lost upon ramming the dockyard.
By 1965 all vessels would receive a large refit, in which they would gain surface search radar, and new engines, swapping their older gray engines for Foden Diesels. They would also begin to act as research and survey vessels. After this refit the class name would be changed to Seaward Defense Motor Launch, as their role had now shifted. They would move their single 20mm mount fore, again only being fitted when needed, otherwise being kept below decks.
However by the late 1969 their time was beginning to end, the hulls were small and limited in speed and capacity, their armament was limited and inaccurate, seakeeping was relatively poor (not as poor as the Lake-class which replaced them, which were helpfully described to me as, “Having both sides of the bridge being soaked at the same time”) and their hulls were very worn, with most vessels having been run aground or rammed into something over their lifespan, of which photos of the consequence are common.
The first vessel would be decommissioned in 1972, with more vessels being decommissioned through to the 1980s. Most of these would become civilian pleasure craft, with the Mako, Paea, Takapu, Q1189 (now the Alert), Tamure, and Pegasus (now the Kuparu ), all surviving and floating. Olphert was laid up and rotted away, being broken up in 2024, Manga was broken up in 2008 due to damage, Tarapunga, Haku, and Kahawi would catch fire and sink while in port, in 2014, 2018, and 1997 respectively. The Toroa, now Koura, is currently laid up in poor condition with no work planned.
They would be replaced by the ill fated Lake-class Patrol Boats, which were superior in almost every aspect to the HDMLs, but requirements for the class were were poorly specified and were not suited for NZ waters.
The sunk HMNZS Ngapona, tied up to the wharf which she rammed.
General Characteristics as HDML (1943-1946)
| General Characteristics: | |||||
|---|---|---|---|---|---|
| Q1189 | |||||
| Country: New Zealand | |||||
| Type: Motor launch | |||||
| Class name: HDML | |||||
| Year of commission: 1943 | |||||
| Refit: 1943 | |||||
| ----------------------------------------------------------------------------------------------------------------------------------------- | |||||
| Dimensions: | |||||
| Length: 72ft (22m) | |||||
| Beam: 16ft (4.9m) | |||||
| Draught: 5ft (1.5m) | |||||
| Displacement: 54t | |||||
| ----------------------------------------------------------------------------------------------------------------------------------------- | |||||
| Propulsion: | |||||
| Powerplant: 2x 8L3 inline 8 diesel engine @ 154bhp (114kW) ea | |||||
| Speed: 12.5kt | |||||
| Endurance: 1,700nmi (3,200km) @ 10kt (19kp/h) | |||||
| ----------------------------------------------------------------------------------------------------------------------------------------- | |||||
| Armament & sensors: | |||||
| Compliment: 12 | |||||
| Primary armament: 1x1 20mm Oerlikon, 2x .50 Browning M2 (Water-cooled) | |||||
| Secondary armament: - nil | |||||
| Tertiary armament: 8 Depth Charges | |||||
| Sensors: ASDIC |
General Characteristics as HDML (1946-1965)
| General Characteristics: | |||||
|---|---|---|---|---|---|
| Q1189 | |||||
| Country: New Zealand | |||||
| Type: Motor launch | |||||
| Class name: HDML | |||||
| Year of commission: 1943 | |||||
| Refit: 1946 | |||||
| ----------------------------------------------------------------------------------------------------------------------------------------- | |||||
| Dimensions: | |||||
| Length: 72ft (22m) | |||||
| Beam: 16ft (4.9m) | |||||
| Draught: 5ft (1.5m) | |||||
| Displacement: 54t | |||||
| ----------------------------------------------------------------------------------------------------------------------------------------- | |||||
| Propulsion: | |||||
| Powerplant: 2x 8L3 inline 8 diesel engine @ 154bhp (114kW) ea | |||||
| Speed: 12.5kt | |||||
| Endurance: 1,700nmi (3,200km) @ 10kt (19kp/h) | |||||
| ----------------------------------------------------------------------------------------------------------------------------------------- | |||||
| Armament & sensors: | |||||
| Compliment: 12 | |||||
| Primary armament: 1x1 20mm Oerlikon | |||||
| Secondary armament: - nil | |||||
| Tertiary armament: 8 Depth Charges | |||||
| Sensors: ASDIC |
General Characteristics as SDML (1965-)
| General Characteristics: | |||||
|---|---|---|---|---|---|
| All vessels 1965- | |||||
| Country: New Zealand | |||||
| Type: Motor launch | |||||
| Class name: SDML | |||||
| Year of commission: 1943 | |||||
| Refit: 1965 | |||||
| ----------------------------------------------------------------------------------------------------------------------------------------- | |||||
| Dimensions: | |||||
| Length: 72ft (22m) | |||||
| Beam: 16ft (4.9m) | |||||
| Draught: 5ft (1.5m) | |||||
| Displacement: 54t | |||||
| ----------------------------------------------------------------------------------------------------------------------------------------- | |||||
| Propulsion: | |||||
| Powerplant: 2x Foden 6cyl @ 163hp (121kW) OR 1x Foden 12cyl @ 256hp (190kW) ea | |||||
| Speed: 13kt | |||||
| Endurance: 1,700nmi (3,200km) @ 10kt (19kp/h) | |||||
| ----------------------------------------------------------------------------------------------------------------------------------------- | |||||
| Armament & sensors: | |||||
| Compliment: 8-10 | |||||
| Primary armament:1x1 20mm Oerlikon (stowed in peacetime) | |||||
| Secondary armament: -nil | |||||
| Tertiary armament: - nil | |||||
| Sensors: - Navigation radar, ASDIC |
- 1x 20mm, 2x .50 M2 Water-cooled Browning (HDML fit, 1943-1946)
- 1x20mm Aft (HDML fit, 1946-1965)
- 1x 20mm Fore (SDML fit, 1965-1982)
HMNZS Haku having run aground, she would be re floated later.
Extra Pictures
Sources:
Wright, Gerry (2010). Salty Dits, Some tales from the MLs by those who served in them. (pp.2-334)
McDougall, R. J. (1989). New Zealand Naval Vessels (pp. 88-95)
Gillett, R. (1983). Australian and New Zealand Warships 1914-1945 (p.298)
HDML Flotillas — National Museum of the Royal New Zealand Navy
HMNZS Mako — National Museum of the Royal New Zealand Navy
Bulldust over a Kiwi BBQ: Composite list of HDML's still active.
Surviving Vessels – The Medusa Trust
https://navalmarinearchive.com/sbh/smallships/hdml.html
https://waitematawoodys.com/2020/04/26/hdml-manga-haimoana/