HMNZS Canterbury (L421)

HMNZS Canterbury is a multi-role vessel (MRV) of the Royal New Zealand Navy. She was commissioned in June 2007, and is the second ship of the Royal New Zealand Navy to carry the name, the first ship having been a Leander class frigate. She is also New Zealand's first purpose-built strategic sealift ship.

However, the vessel has been plagued by problems since delivery, having been involved in a number of incidents and being considered less seaworthy than specified. It is estimated as of 2008 that at least another NZ$20 million will have to be spent to achieve the sought-for operational abilities.

Planning and design
As early as 1988 the Royal New Zealand Navy had identified the need for some form of sealift in the South Pacific. In 1995 this led to the commissioning of HMNZS Charles Upham. The subsequent failure of successive governments to fund the required refits resulted in Charles Upham being sold in 2001.

At the same time the newly elected Labour Government directed the navy to exclude the option of a third frigate from the Maritime Forces Review, while the sea lift requirement was also part of a wider capability mix desired.

Construction
The construction of the MRV was sub contracted-out to Merwede Shipyards in the Netherlands by Tenix Shipyards in Williamstown, Melbourne, with the design based on the commercial RoRo ship Ben my Chree. However, the choice of a commercially based design has been criticised after the ship was delivered, as it placed several limitations on the functionality of the ship in rough seas – rather than the coastal environment for which Ben my Chree was designed.

The keel was laid on 6 September 2005 and the MRV was launched successfully on 11 February 2006. The ship completed initial sea trials in the Netherlands and arrived in Australia in late August 2006 for fit-out with military equipment. Final acceptance was delayed due to alterations to the ships hospital and late delivery of documentation. There were also ongoing concerns, negotiations and redesign activities regarding her performance in heavy seas, doubts about which had already been thrown up during her initial journey to Australia, and in fact, even before actual construction.

The MRV was accepted by the New Zealand Government on 31 May 2007 and commissioned on 12 June 2007 in Port Melbourne, Australia by the Prime Minister of New Zealand, Helen Clark. The ship cost NZ$ 130 million to construct.

She was constructed with an ice-strengthened hull to allow her to operate in the subantarctic waters, where New Zealand claims several islands, and where Canterbury is to assist scientific expeditions.

Initial exercises and operations
After commissioning, the ship sailed to its home port of Lyttelton arriving 28 June 2007. After several days of inaugural events, it departed again on 2 July. Following a courtesy visit to Timaru and after a month-long set of trials and exercises in the Auckland area, where she is operationally based at Devonport Naval Base, she is to head to New Zealand's subantarctic waters carrying DOC conservation officers.

In September 2007, Canterbury embarked 250 troops and 50 vehicles, including 20 NZLAV armoured vehicles, to test embarkation and disembarkation procedures.

AU-NZ disaster relief response force
In early 2011, it was announced that the ship would form the core asset of a joint Australia-New Zealand task force for disaster-relief operations. It was noted that Canterbury was currently the only appropriate vessel available to the navies of the two countries for such tasks, as three other similar-capability ships of Australia are unavailable long-term due to significant maintenance issues.

Coincidentally, the newly appointed disaster-relief ship was in the port of Lyttelton less than two weeks later during the devastating February 2011 Christchurch earthquake. The crew provided meals for 1,000 people left homeless in that town, and accommodation for a small number of locals.

2012 Kermadec Islands eruption and pumice raft
The HMNZS Canterbury was the first ship to take scientific samples from a 7,500–10,000 square mile pumice raft that was discovered in the Kermadec islands.

Armaments
As a sealift ship, Canterbury is not intended to enter combat, or conduct opposed landings under fire. The ship's armament consists of a single 25 mm M242 Bushmaster cannon fitted to an MSI DS25 stabilised mount, two .50 calibre machine guns, and a number of small arms. These are intended for self-defense against other smaller craft, and for ocean patrol duties (for example the intercepting of suspicious civilian craft) during a naval blockade.

Facilities
The ship has cargo space of 1,451 m2, which can be unloaded via two ramps, either from the starboard side or the stern.
 * Cargo

The indicative cargo would encompass (as one possible loadout): 14 Pinzgauer Light Operational Vehicles, 16 NZLAV light armoured vehicles, 7 Unimog trucks, 2 ambulances, 2 flatbed trucks, 7 vehicle trailers, 2 rough terrain forklifts, 4 ATV-type vehicles and up to 33 20 ft TEU containers.

The ship is equipped to embark up to eight containers of ammunition and up to two with hazardous materials, and also has an extensive fire sprinkler system.

The ship also carries two Landing Craft, Medium. The landing craft have a length of 23 m and a displacement 55 tonnes (empty) to 100 tonnes (loaded with two NZLAVs). They are operated by a crew of three, using two Azimuth thrusters generating 235 kW.
 * Landing Craft

The LCMs can be loaded from either of Canterbury's two 60 tonne cranes or via the stern ramp. To aid stern ramp loading, the MRV is fitted with Flippers to ensure that the LCM are aligned with the MRV. A ballasting system is fitted to allow for safe operations during loading. Once loaded, the LCM can conduct over-the-beach landings, with the boats mainly intended to be able to access beaches in the Pacific where no port facilities are available, for example during humanitarian missions.

Due to varius issues (discussed further below) the original landing craft were decided in 2010 to need replacing. The fate of the current craft is currently undecided.

Canterbury is able to accommodate up to four NH90 hellicopters for deployment ashore in support of New Zealand Army operations and disaster relief activities. She is also capable of operating the SH-2G Seasprite and the helicopter deck is able to handle a Chinook-size helicopter.
 * Helicopter facilities

Canterbury has a five-bed hospital ward, a two-bed sickbay, an operating theatre, a medical laboratory and a morgue.
 * Medical

The ship also contains a gym, workshops, an armoury and magazine, as well as offices for government officials embarked (such as Department of Conservation or NIWA scientists).
 * Others

Issues
The ship has been plagued by a number of issues, most of them related to faulty design, or design inappropriate for the intended operating conditions.

RHIB & Landing craft issues
Canterbury weathered her first strong storm during 10 July 2007 well, though she lost one of her RHIBs (and almost lost the other) to waves swamping her open boat bays while near Tauranga on the way to Auckland. The RHIB was found a week later washed ashore on Great Barrier Island, 200 km to the north, and recovered by a farmer. The heavily damaged boat was to be returned to the navy, though it is unclear whether it can be repaired.

A court of inquiry found that the loss was due to a known design flaw identified in tank testing. The flaw resulted in the loss of the RHIB and water entering the cargo deck after the doors were opened by the sea. As a result of this the doors were tied shut. The court of inquiry also reported slamming of the bow and propellers leaving the water. Options to resolve the design problems on the ship include closing the alcoves in which the ships boats had been stowed. At the time the RHIB was lost, the ship's log records the weather conditions as being a wind strength of 60 kn, gusting to 73 kn, a swell of 6 m (sea state six), and a completely overcast, very dark night. The alcoves are 3.3 m above the waterline and were swamped by the waves and because the ship was experiencing severe motion, rolling up to 28 degrees to port, at a roll frequency of 11.5 seconds. The ship's anti-roll system will not function when the period of the ships roll is less than 11.9 seconds. Work to relocate the boats in a less vulnerable location is underway.

In October 2007, a crewmember was killed when an RHIB capsized whilst being lowered into the sea. The Navy immediately began an inquiry into the accident. Defence Minister Phil Goff later reported that it was caused by the failure of a quick release shackle, which was now being replaced on all naval vessels.

In November 2007, Lieutenant General Jerry Mateparae said that certain issues were being discussed with the shipbuilder including the location of the Rigid-hulled inflatable boat(RHIB) on the quarterdeck from which it was torn off during the storm in July, possible fatigue problems with the landing craft fittings, and some other issues.

New Zodiac inflatable sea boats were ordered from Tenix Australia to replace the two Gemini sea boats that were damaged.

In 2010, it was decided that two new Landing Craft would have to be built for Canterbury, as they experienced a variety of issues, from material problems experienced with weak bow ramps, to stability problems, which severely curtailed their usability. The Australian builders of the ship, BAE Systems, agreed to pay $85 million towards remedying the faults of the ship, including the construction of the new landing craft.

In 2013 two new shell doors on deck 3, and two new accommodation ladders on deck 5 were designed and installed by Taranaki engineering firms ITL and EHL. Marine Industrial Design and Babcock NZ made the necessary structural changes. The RHIB was able to be relocated as a result of the innovative design of the new accommodation ladders which can stow compactly inside the ship (5x2.5x2.5m), rather than being externally stored alongside the ship as before. Improved design of the ladders and the relocation of the RHIB has increased the safety and capability of the ship is no longer compromised.

Sea keeping performance
In September 2008, an independent review of the safety and functionality of the ship revealed that some operating limitations will have to be accepted, as sea keeping performance is poor in high sea states. The "selection of a commercial Roll-on, Roll-off (Ro-Ro) design" has "been at the root of differences of opinion between Tenix, the Ministry of Defence and New Zealand Defence Force and the shortfalls in performance". The issues included that the propellers can come out of the water when the ship pitches in rough sea, with concern that this may affect the ship's machinery. The report also recommended relocating the ships boats (or protecting them from waves if relocation was not possible) and adding more ballast or improving the ballasting system of Canterbury.

These upgrades have now been completed. The RHIB alcoves are now further forward and higher. Also more ballast has been added to help with sea keeping. This was all completed before the Pacific Partnership 2013 Exercise.