Honestly I think the NZDF would be better served ordering one of the existing LPD designs with suitable modifications, as opposed to ordering an LHD, either one of the existing designs or having a new one custom-designed for NZ.
It would not be better served and would be entirely undesirable unless it was an evolved and slightly enlarged Fincantieri BDSL with an adequate deck lift, thus an LPD with better aviation capability (i.e at least 3 deck spots) than the present CY and many of the other LPD’s that were once built.
The notion of having an future amphibious vessel design in the context of the post 2030 NZDF and its principal SouPac AOO that has design limited HVL (helicopter vertical lift) capacity with deck two deck spots at best, such as the traditional LPD designs would significantly limit the capability of the NZDF to do its long term future role in both combat support and HADR. Any future amphibious asset will be the cornerstone of NZDF operations in its primary area of interest (the South Pacific) in the decades to come.
While the notion of more flight deck and/or hangar space might seem appealing, how much 'more' is really useful?
Thankfully the research has answered your question. The value of helicopter vertical lift as the key enabler to success in conducting HADR support missions has been well traversed and is a good starting point as noted in Moffat (2014) as well as Elleman (2004), Clementson & Fisher (2011) and Goldman (2013), who scoped the context JMSDF amphibious capabilities.
Moffat (2014) outlined the transformative role that LHD’s in the context of HVL operations play.
In every instance that the U.S. Navy provided relief in HA/DR missions, the helicopter was the essential asset. When determining how much capability a ship has in providing support for a disaster, one must first look at how many helicopters the ship can bring, if any at all. While some ships can provide different types of support, this premier asset should be regarded as the highest priority.
This is especially so in the context of the NZDF’s principal area of operations the South Pacific, where a complex event such as HADR response requires an intense range of multi-factorial taskings. In particular with respect to any amphibious assets having to deal with responding to events in multiple inhabited islands frequently with little or no infrastructure that require a distributed response over a huge geographic area. For example from ship to shore cargo of varying sizes and amounts, ship to shore (and inverse) personnel transfer in often evac, medevac/ patient transfer, damage assessment and SAR all requiring a rapid response. With an LHD as opposed to older LPD designs these taskings are able to be done concurrently, to different locations and underpin time sensitive advantages. This directly translates to the LOE (Lines of Effort) required achieve the mission success. As the literature outlines HVL capability is the critical requirement in succeeding this HADR context.
Greenfield and Ingram (2011) in their research into HVL’s within HADR missions developed a quantitative methodology to analyze the respective capabilities of various vessels by platform type in terms of undertaking HADR operations. The LHD design received 480 capability points verses the 120 points allocated to traditional LPD designs with the key differential being the enhanced HVL capability LHD’s provide in HADR response.
Equally the same range of tasking criteria applied in a combat scenario in which the added element of force protection applies. HVL’s as you know are fundamental enablers of ground manoeuvre, allowing troops to circumvent difficult terrain and to bypass ground threats, to rapid troop movement and re-supply. When married to New Zealand’s emerging agile light infantry force structure as outlined in FLOC and the recognition of the predominant SouPac operating environment that NZ Forces are likely to deploy to as part of the JATF, whether that be across the tasking spectrum from HADR to MIC Chp VII events, a LHD is the far superior future vessel platform for the NZDF than a traditional LPD.
With the 2016 Fiji HADR deployment the CY had to forward deploy the two NH90 on shore 200kms away as there was insufficient onboard vessel capacity to handle the flight tempo whilst conducting other support activities. That created an additional strain in LOE in logistically supporting them. A CY with a well dock would not do much better as two LC’s wont provide the required multi-factorial response and completion speed of a HVL. The Fiji HADR mission exposed other capability gaps with CY – it was not big enough with the OPV Wellington also required to bring in a further 70 tonnes of Aid, plus the hydrographic and diving teams, and army engineer personnel numbering around 70. Thus taking away that vessel from its scheduled taskings and taking a week later than CY in getting the Aid into place. Unfortunately, an additional and highly useful SH-2G was not embarked as it obviously could not be supported from such a small and austere vessel and there was no capacity on the CY.
Using the HMNZS Canterbury (an LHA) as an example, there is hangar space for four helicopters, and landing spots for two medium helicopters or one Chinook IIRC.
Following the CY’s Get Well re-configuration the hanger space is only now only realistically usable for a Sea Sprite and 2 NH-90s with limited on ship flight support if flying operations are to be conducted off the single landing spot on the deck. You are certainly not able to conduct concurrent TOAL using two HVL assets off the CY’s flight deck with rotors running nor underway. Only under a bona fide emergency would a NH90 and Sprite be sharing the deck concurrently.
Given that across the whole of the NZDF there are only eight transport helicopters in total, trying to pack more onto a single ship does not sound like a good idea to me.
That is a classic fallacy of equating a current minimum rotary capability which was set for political reasons 15 years ago and extrapolating that with what will be required post 2030 and the 3 decades following that when replacement ship to CY is likely to be in commission. It is extremam rationem to suggest that somehow we would be carrying all eight NH-90’s on any amphibious vessel. How about the capacity to at least store 4 NH90s and 2 Sprites within the hanger space that has a sufficient maintenance area and have 3 landing spots on the deck one of which could handle a visiting allied Chinook or V-22, and a deck lift?
Another area of concern is what would be a reasonable troop and vehicle capacity? Having gone through the various LHD classes currently in service, the smallest (which is really more of a modified LPH) is ~19,000 tons at full load and can lift ~720 troops and ~200 vehicles, while other designs can very the numbers of troops and vehicles they are still significantly greater than NZ would be able to field.
That sounds like the Dokdo and Wiki have collided into misinformation. No you can certainly not carry 720 troops and 200 vehicles at the same time. You can carry around 30 vehicles and 720 troops for a short duration with austere facilities on Dodko.
It is sophistic to equate that because a certain vessel design in current operation might possibly be a larger than what is required for the NZDF. There are a number of scalable LHD designs that are smaller than 19000 ton (whatever tonnage calculation you are using). The Athlas 13000 LHD based on the Enforcer family. The 14000 ton Mistral 140 is another and so is the HDW’s MRD-10000 design. And significantly for NZ because the Koreans loom large in RNZN maritime relationships, HHI has the scalable MSRV series of 10000 to 16000 ton designs, which are both available in LPD and large deck LHD designs. Like the in the case of the coming 24000 ton Aotearoa, we can order exactly what we require in the size and timeframe we require it, a vessel that was built with future proofed capacity and capability in mind, no doubt a lesson learnt by the RNZN with respect to the capacity limitations of the 9200 DWT of the current CY as noted in the Coles Report and born out with Wellington having to be re-tasked at short notice to make up the difference.
There is the Fincantieri BDSL for the Algerian Navy mentioned earlier, which is in effect an LPD for its modest size at around 9000 DWT offers similar sealift to the CY but with a well-dock and a slightly increased HVL capability providing 2 main flight spots and storage for 4. However it does not have a deck lift.
