Multi-role support ship (UK)

The Multi-Role Support Ship (MRSS) is a planned class of up to six multi-mission amphibious warfare ships in development for the United Kingdom's Royal Navy. The ships were first officially mentioned in the British government's 2021 defence white paper, titled Defence in a Competitive Age. In May 2024, funding for the ships was announced at the Sea Power Conference in London. They will replace the service's two Albion-class landing platform docks, three Bay-class landing ship docks and the multi-purpose support ship RFAUX Argus (A135).

Background
The Royal Navy currently operates two Albion-class landing platform docks for amphibious warfare which are augmented by three Bay-class landing ship docks and one support ship (RFAUX Argus (A135)) from the Royal Fleet Auxiliary. With the exception of Argus, these ships were originally commissioned in the 2000s and designed to deliver a brigade-level amphibious landing force. All six ships are due to retire from service in the 2030s.

In the 2020s, the Royal Navy began a modernisation of its amphibious forces in accordance with its new Future Commando Force doctrine which emphasized lighter, more agile raiding operations for the Royal Marines. The navy's amphibious shipping was subsequently reorganized into two formations, known as Littoral Response Groups. In 2022, it was announced that RFA Argus would undergo modifications to allow her to fulfil a new role as a littoral strike ship.

In 2021, the UK government made its first official mention of the MRSS as part of its 2030 shipbuilding pipeline. In 2022, the ships were removed from the Royal Navy's future equipment plan due to issues of affordability. However, the navy insisted the ships remained part of its future plans.

Concept phase
The MRSS officially entered its concept phase in 2021.

UK-Dutch cooperation
In September 2023, the UK and the Netherlands signed a Memorandum of understanding announced to explore the joint procurement of amphibious warfare ships under Project CATHERINA. This could have seen the six Royal Navy's amphibious vessels and the Royal Netherlands Navy's two Rotterdam-class landing platform docks and four Holland-class offshore patrol vessels replaced with a single shared design. Such a venture would not only bring greater economy of scale but would also better solidify the programme politically by helping to protect from possible budget cuts. However, in March 2024, this main effort was reportedly abandoned as the two parties identified that their requirements and budgets were too divergent for a single design to successfully meet. CATHERINA would instead re-focus on Anglo-Dutch coordination on subsystems, landing craft, and aviation. One key difference was the ships' ability to operate independently without an escort a British preference which would require more substantial self-defence capability.

MRSS commencement
Following an announcement by Defence Secretary Grant Shapps at the Sea Power Conference in London, the programme officially received approval to commence with its first phase on 14 May 2024. Currently, the MRSS's are planned to enter service in the 2033/34 period, with three ships to be built initially and a plan for up to three additional vessels. The ships are envisaged as flexible, multi-purpose amphibious warfare platforms, capable of landing marines ashore via sea and air. The ships will feature well docks for landing craft, hangars capable of accommodating Chinook helicopters and a flight deck for helicopters and uncrewed systems. The ships will be highly adaptable and interchangeable by design, as well as interoperable with NATO allies. Lessons learned from the Russo-Ukrainian War and the Red Sea crisis will also factor in the design. The ships may also require fewer crew members than their predecessors.

Design contenders
Prior to the initiation of a formal competition, a number of designs have been raised as contenders for the MRSS programme. Following the commencement announcement in May, Shepard News reported that BMT could offer their 'ELIDA' product line whilst Prevail Partners may put forward with their 'Multi-Role Vessel' design.

ELIDA
Unveiled in 2019, the original concept design for ELIDA was a multi-role auxiliary vessel designed to perform as both a solid stores ship for fleet replenishment-at-sea (RAS) and as a auxiliary landing vessel similar in capability to the Bay-class. At DSEI 2023, BMT unveiled a revised ELIDA design. This second generation design consist of vessels 130 metres, 150 metres, 180 metres, or 200 metres in length. The revision saw the removal of the RAS rigs from the design and brought the superstructure more forward and reduced the size of the forward working deck.

ELIDA features two internal open deck areas for stores and other equipment as well as a forward external deck area for Twenty-foot equivalent unit (TEU) containers which is serviced by two deck cranes. BMT have not publicly stated if ELIDA's general characteristics have changed from those of the first generation design which had (in reference to the 200m variant) a range of 8,500 nautical miles, a service speed of 18 knots and a crew of 68. In the amphibious role ELIDA could embark a military force of 350 personnel with an internal 700 lane metres for vehicle stowage, a well-deck for two LCUs, and a hangar for one AW101 Merlin with temporary storage for an additional three.

FEARLESS
During the Combined Naval Event in late May, Stellar Systems unveiled their FEARLESS design and was the first to publicly state their intention to forward the design for consideration for the MRSS programme. The design represented a more radical and innovate approach to traditional amphibious vessel design by effectively creating a hybrid surface-combatant, mothership, and amphibious vessel.

FEARLESS appears visually to be a development of Stellar Systems' SPARTAN frigate design previous submitted in 2017 as a non-finalist contender for the Type 31 programme. FEARLESS is 170 metres in length, displaces 15,500 tonnes at full load, and has a range of 7000 nautical miles at 18 knots. FEARLESS is propelled by podded propellers with contrarotating electrically driven shafts which, combined with an AI optimised hull, enables the ship to achieve 30 knots whilst reportedly using less power than a Type 23 frigate. FEARLESS features a significant armament, with the model displayed at its unveiling outfitted with 40 strike/tactical length VLS cell, a 127mm and 76mm gun supported by two Phalanx CIWS, three 30mm guns, two DragonFire L-DEWs and three trainable decoy launchers. The featured armament is said to allow a FEARLESS vessel to operate in heavily contested littoral areas.

There is a working deck amidship capable of holding five containers or mission modules, docking stations for uncrewed surface vessels, two boat bays, and has hangar space for two AW101 Merlins. The hangar has access to the vehicle deck with 800 lane metres of space. Notably, FEARLESS lacks a well-deck, instead featuring a stern-ramp capable of handling up 30 tonne craft up to 20 metres in length, with a vehicle ramp that can deployed to support ground vehicles up to 60 tonnes. Unlike a well-deck, the ramp allows for drones, landing craft and other vessels to be embarked / disembarked in higher sea states but would remove the ability to utilise the larger LSU, limiting shore landings to the Mexeflote or Commando Insertion Craft (forthcoming LCVP replacement).