A fair amount of ink has already been spilled on this issue, with some speculating that the vessel will be a landing platform helicopter (LPH) that could function as a quasi-aircraft carrier. It has further been contended that the JMMS would likely be a through-deck vessel — a ship with a flat surface running its entire length allowing planes to land and take off — armed with F-35B fighter jets that Singapore is buying from the United States. This pairing, it is argued, could act as a mobile airbase during a conventional war.

But this argument is problematic on various counts. The idea that the JMMS ‘will function as an aircraft carrier’ largely came about because some observers superficially commingled the JMMS acquisition with the through-deck Endurance 160 model made by Singapore Technologies Marine, the republic’s indigenous shipbuilder. The point that the JMMS is likely to be through-decked references an article that alludes to such an eventuality but without stating its sources.

An infographic of the JMMS carried by Singapore state media outlet CNA in 2018 shows that the vessel is anything but a through-deck platform. This is the same as an infographic released by the Republic of Singapore Navy (RSN) itself in the same year. In this picture, the vessel’s superstructure is located near the bow and there is no provision for a through flight deck that is essential for deploying short take-off and vertical landing tactical aircraft like the F-35B. This rendition of the JMMS resembles that of a landing platform dock much like its predecessor — the Endurance-class vessel — that is currently in RSN service.

In 2019, the defence ministry unveiled another, albeit blacked-out, infographic of the JMMS. Its silhouette hints of the Endurance 160 to some extent — but even if the RSN really acquires the said platform, operational limitations would preclude its deployment as a quasi-aircraft carrier.

Collin Koh and Bernard Loo discussed some of these considerations in March 2015. One of the main factors they point out that would limit the JMMS’s role in force projection is the platform’s relatively small size, which would likely afford a miniscule air wing of not even a dozen fighter jets. Other countries already face this ‘small-deck carrier quandary’.

Simply put, this conundrum revolves around what proportion of such a ship’s relatively small fighter complement should be allocated to defence and offence. Given the JMMS’s capital-ship status, the air group’s priority should be protecting its mother ship from threats, rather than power projection. And even if the latter were to take place, would it amount to anything more than a pinprick strike?

In sum, the JMMS would not be effective as a base for fixed-wing aircraft operations. But Koh and Loo rightly note that the vessel could act as a command-and-control platform for overall military operations. Besides that, its aviation capabilities could have some utility in a ‘hot war’. Regardless of its final configuration, a more conceivable fighting role for the JMMS is that its helicopters could deploy under more permissive operating conditions light-infantry or special-operations troops to strike at the adversary’s centres of gravity.

Given the JMMS’s mobility, these missions could be carried out from an unexpected quarter, complicating the enemy’s calculus. The vessel, if suitably modified, could also act as a forward arming and refuelling point at sea for land-based F-35Bs on long-range sorties. Joint Strike Fighters flying from mainland Singapore could make a ‘pit stop’ on the JMMS before continuing with their missions. Of course, this raises the question of whether Singapore defence chieftains would contemplate enabling the JMMS to be fixed wing aircraft-capable at considerable cost for an extreme scenario.

The JMMS debate parallels a similar conversation in Australia, where the media is discussing whether the Canberra-class LPHs should be retrofitted to deploy the F-35B. This comes after Japan revealed that its Izumo-class ‘helicopter destroyers’ will become F-35B-capable.

All that being said, details about Singapore’s upcoming JMSS program have been and will likely remain shrouded in secrecy — at least for the near term. This will no doubt continue to fuel speculation over its raison d’etre.

What is perhaps clearer is that Singapore is likely to continue its long-standing gradualist approach towards arms procurement. The JMMS should be no different in this regard. Post-2030, when the platform is expected to launch, we can expect to see an ‘Endurance 1.5’ rather than an ‘Endurance 2.0’ to enter service.

Ben Ho is an Associate Research Fellow with the Military Studies Programme at the S Rajaratnam School of International Studies (RSIS), Nanyang Technological University, Singapore.