The Type 26 frigates being built for the RN have been designed from the outset with a mission bay. In the first part of a 2-part article, we examine the design, layout and implications of this flexible space.
The mission bay concept is not a new innovation and several navies have fielded warships with a ‘flexible mission space’ for some years. The growth in unmanned naval warfare technologies and off-board systems offer a whole new way to equip warships and every self-respecting surface combatant design of today includes space for them. The Type 31e frigate design competition is currently underway and the winning candidate is likely to include a mission bay of some kind. A mission bay is not a ‘core’ requirement of the official specification, although a bay and/or deck space for modular payloads (2 x ISO containers) is a preferred option. Of the 3 outline designs in the public domain right now, the BAE Systems ‘Leander’ appears to be most developed in this regard. The Type 31e will probably be the first mission bay-equipped warship in service with the RN and will offer a way to trial different payloads and operating doctrine, in advance of the of the more spacious and well-equipped Type 26.
The mission bay, sometimes termed the Flexible Mission Space (FMS) occupies the full width of the ship and is about 20m wide by 15m long. Access is through two large roll-up shuttered doors on either side of the vessel, although there is also access from the forward end of the helicopter hangar. The possible combinations of items that might be placed in the mission bay are endless but the RN has said it expects space may be used for:
- UAVs, UUVs and USVs
- Maritime interdiction boats
- Humanitarian aid and disaster relief (HADR) Stores
- An enhanced medical facility
- Additional accommodation
- A holding area for captured personnel (CPERS)
The Type 26 is primarily an anti-submarine platform designed to escort aircraft carriers but has very significant capability in other roles. The mission bay is a key part of this flexibility and allows the ship to be rapidly reconfigured for alternative missions. What is perhaps most overlooked is the ability to act as an amphibious platform for raiding or special forces operations. (Interesting in light of the recent announcement of plans to add further to this capability with dedicated Littoral Strike Ships) The mission bay can hold four 12m boats for troop insertion. A Chinook can be landed on the ship (although not housed in the hangar) and the flight deck has sufficient space for its ramp to be lowered to embark 30-40 fully equipped troops. The ship has extra accommodation for an embarked military force of up to 50 personnel, although this could probably be increased further for short periods.
The Type 26 is fairly unique among escort warship designs in having a very wide transom that does not taper at all. This allows space for line-handling in cutouts in the flight deck and plenty of space on the deck below for the towed array sonar equipment. The requirement for a Chinook-capable flight deck (c30m x 20m) is a big factor in driving the up the displacement of the ‘frigate’ to about 8,000 tonnes but makes for much more comfortable helicopter operations. The hangar is capable of housing a Merlin or two Wildcat helicopters. Theoretically, a second Merlin could be accommodated by bringing one forward into the mission bay. With one kept on the flight deck or airborne, this might offer a sustained, round the clock ASW capability in the absence of an aircraft carrier. A shutter can close off the hangar from the mission bay, primarily to prevent the spread of fire. As the hangar is often used for social or diplomatic functions it may also be useful to hide the contents of the mission bay from public view at times.
Mission bay enablers
Although a flexible mission space is a simple concept, there are a surprising number of additional elements needed to make it safe and efficient to be used operationally at sea. Like most compartments in a warship, the bay will need basic lighting, ventilation and fire-fighting arrangements. With such diverse potential items stored in the space, there will need to be flexible means for securing them. ISO containers require correctly spaced deck sockets and are secured using twist locks. Containerised modules may hold sensitive electronics and, for use in a naval environment, will need shock-protection mounting. Accommodation or mission modules intended to be used by personnel when on the ship will rely on the ship’s services to supply power, heating, ventilation and air conditioning (HVAC). With a wide variety of boats and bulky unmanned systems to embark each may require a bespoke cradle to secure them tightly to the deck when at sea.
Without a means to move items in and out of the mission bay, it is merely an empty space in the ship of limited value. The Mission Bay Handling System (MBHS) is a critical and complex mechanical system that must meet some demanding specifications. The primary requirement is to safely deploy and recover boats and unmanned vehicles from both sides of the ship when at sea while subject to rolling and pitching motions. The MHBS must also have sufficient reach to cover all areas of the mission bay and have attachments capable of lifting items with a variety of weights and dimensions. To allow the ship to use austere port facilities, the specification also calls for a self-loading/unloading capability. The MBHS has to have the strength and reach to load or offload containerised mission packages from the jetty without the aid of dockside cranes. It would appear that items for the mission bay are intended to be loaded via the doors on each side of the ship and not usually through the hangar. Mock ups suggest the MBHS would have a limited reach within the hangar area.
Rolls-Royce Canada based in Peterborough, Ontario has considerable experience manufacturing marine container and load-handling equipment for the commercial sector and signed a Design and Development Agreement for the Type 26 with the MoD in 2014. The contract for the manufacture of the MBHS for the first three ships in was awarded in February 2018 and RR Canada is also manufacturing the low-noise propellors for the Type 26. The inclusion of Canadian industry in the project at an early stage was a sensible strategy that undoubtedly contributed to the selection of the Type 26 design for the 15-ship Canadian Surface Combatant. With an international programme to build up to 35 frigates that are all likely to use the MBHS, this is an example of how economies of scale may reduce costs for all three participating nations.
The MBHS is based on a commercial rail-mounted Launch and Recovery System (LARS) and uses a mix of hydraulic and electro-mechanical actuators to slew, lift and telescope. It can transverse the width of the bay on athwart-ships rails mounted on the deck-head. When launching or recovering boats, a constant tension winch is controlled using an Active Heave Compensation (AHC) system. AHC can precisely sense vessel motion and automatically compensate by adjusting the winch speed and direction. The MBHS will require attachment heads designed for the different type of loads. Besides the winch and grab mechanism used for lifting boats, a beam spreader for lifting containers will be required as well as a crane and hook for moving smaller loads. Different lifting attachments may be developed in future to suit the weight and shape of evolving unmanned systems. Although 20-foot ISO containers can theoretically hold up to 22 tonnes, the mission modules will be limited to the MBHS capacity of 15 tonnes.
The boat bay
The Type 26 design includes a separate boat bay on the port side. This gives the ship has at least one general purpose sea boat, in addition to whatever other boats may or may not be carried in the mission bay. The RN is currently receiving deliveries of 60 new BAE Systems Pacific 24 Mark 4 RIBs. These boats are a major improvement on the Pacific 24s currently in service, being SOLAS certified, having a 370Hp V8 engine giving speeds up to 38 knots and fitted with SHOXS shock-mitigation seats. RN vessels are not be certified as safe to deploy until they can demonstrate their sea boat can quickly recover personnel lost overboard. The sea boat also performs important operational roles – for boarding other vessels and transport of personnel. The Pacific 24 is set to remain as the standard RIB employed by the RN for some time and will see service on the T26. The Type 26 boat bay is likely to be a similar design to that of the Type 45 destroyers.
The size of Type 26 offers the potential for its use as the basis of the design for future combatants. An air defence or anti-ballistic missile variant could perhaps replace the mission bay with additional vertical launch cells. The design features some spare electrical generation capacity but should it be insufficient for the needs of future directed energy weapons (DEW), then it is possible that extra power generation modules could be installed in the mission bay. There are very few disadvantages to having a large spare space in the superstructure of a warship and the mission bay is likely to prove very useful in service and embark equipment that has not even been imagined yet. In the next article, we will examine some of the potential configurations and types of payloads that might be carried.
Very interesting article. It’s nice to see that a lot of thought has gone into this ship, in particular including components from other countries which helped make it easier to sell the design. On another note, this petition has now received over 11,000 signatures and is waiting a Govt response:
https://petition.parliament.uk/petitions/235377
Please sign and share if you haven’t already
Interesting point about using the mission bay space for additional VLS for the future destroyer. The concept of a T46 certainly isn’t new, but I personally always assumed the hull would be stretched forward to allow a single large VLS farm (most likely 48-64 cells).
An amidships farm would likely produce the same or greater potential VLS capacity for a lower unit cost due to less modifications needed to the basic hull, but it would also result in a great deal of lost capability with little or no mission space.
Is a multi-mission bay really required on a specialised AW destroyer? Fit 32-64 tatical length mk41 straight down the middle of the mult-mission bay & turn the outer edges into boat bays. This would give 64 – 96 cells, 32 of which are strike length (current RAN/RCN). Keep the base design the same but build in ability to swap relatively easily, by only requiring directly affected blocks to be changed. ie a half built T26 should be able to convert to T46 or the other way round by just changing the m-m bay & radar. I realise there is more to it than that, but keep the basics simple & the majority of the construction will not miss a beat.
Unfortunately, it is basically guaranteed that this programme is likely to follow the Type 45 process where cost blowouts and over-engineering are likely to lead to a large cutback in the number of ships ultimately delivered to pay for the cost blowout. I predict a maximum for 4-5 will ultimately be delivered.
There is absolutely no need for a frigate to displace a massive 8000 tonnes. The ability to land a chinook helicopter on it delivers a very poor cost to benefit ratio. Much more cost effective to design a frigate to actually be used as a frigate and have dedicated amphibious assault ships for this purpose. This would allow the Royal Navy to have a larger number of ships.
David,
I share your concern regarding unit cost, the T26 is certainly a very capable design however.
The RN actually needs 16 such ships moving forward to support a global trade network and a follow on stretched destroyer derivative to supplement and eventually replace the T45.
A sensible number would be 16 T26, 12 air defence destroyers, (T45 plus future class)
and 12 T31 GP frigates.
That takes us back to a sensible force mix and a balanced and flexible escort force with elements based abroad.
I would like us to have more ships but I don’t think we could ever crew your fleet. I think a more sensible force mix would be 6 x Type 45 (fully crewed), 8 Type 26, 6 Type 31 as well as reactivation of the 2nd LPD and finding enough bodies to fill the River Batch 2s (almost double the crew of Batch 1s). This will be hard enough, the manpower problem is not going away anytime soon.
The problem is the timeline. If you had a crystal ball 15 years ago, you’d have commissioned Type 31 first, and designed it as a 5,000 ton specialist ASW frigate that inherited its TAS from the T23s. Then you could get on with building a class of 5 or 6 cruisers with a big multi-mission space. This would tally fairly well with the original Future Surface Combatant and S2C2 program goals of delivering a high end independent warship capable of operating unsupported to deal with what were called “brushfires” or contain a situation long enough for support to arrive, alongside a second tier, cheaper and more numerous design for general escort duties (which is, basically, ASW and surface, with a bit of missile point defence).
Type 31 should cost at least £500m and get the full ASW suite of TAS, combat system, quiet engines/propulsion, etc. and concentrate on being a Type 23 successor, while Type 26 is the general purpose globe trotting cruiser. Then we only need about 5 Type 26s, so long as there are at least 8 to 10 Type 31s.
Ah, but 20:20 hindsight is a wonderful thing.
Yes, it all sounds great,but what we are talking about here is mission creep, basically a cruiser.
Seems a general navy approach to avoid the political resistance of asking for a new class of ships is to;
(a) ask instead for ships of the next class ‘down’ in size
(b) increase the size of these ships so they are comparable in tonnage/length to the next size.
We’ve seen it with the Invicible ‘through deck cruisers’ – aircraft carriers, the Daring class destroyers – cruiser sized, and T26 frigates – destroyers.
That said, I welcome anything the RN can do to hoodwink politicians in order to get the ships it needs.
Another great article, this is a great site for in-depth pieces!
Indeed
The mission bay and the MBHS are just frustratingly too small to accommodate and launch a CB90, which weighs in at 20 tons full load, 12 tons empty and is itself 15 metres long, which will make it 3 metres too long to fit out the door!
Having said that, I wonder if a 20 ton baby fast attack craft hanging off the crane would make the whole frigate list, even if mother is 8,000 tons!
CB90 is a good bit of kit, lucky enough to have a go in one some years ago
I wonder if we could get the production line for the SB90E variant of the CB90 restarted? It was a smaller version intended for insertion, so probably didn’t have the armour and CRBN capabilities of the CB90, but it would fit inside a Type 26.
Length: 10.8m
Beam: 2.90m
Draft: 0.7m
Displacement: 7.2t
Range: Approx. 200 nm
Max. speed: Approx. 42 knots
They’re also used aboard the Absalon class.
Inevitably, Think Defence did an article on the CTruk Thor that would be a much better fit (literally, at 11m and 9 tons) back in 2015.
Call me a sync, but I can’t help feeling like the Flexible Mission Bay concept was a way for the MOD and the treasury to gain a convenient excuse for not arming this ship to its full potential due to the usual cost cutting exercise. Given that it its primary role is high end ASW, I feel that it should have had a potent dedicated Anti Submarine weapon system like a ship based spearfish torpedo launching Magazine or VL-ASROC launched from the Mk 41 VLS Cells. Whilst a bear minimum of Stingray Lightweight Torpedo Magazine Launcher. The above mentioned should be combined with the potent ASW Helicopter capability that RN is already operating. I also feel there could be enough space accommodation for future UUVs for extending the ranges of ASW detection and MCM operations using the Mothership concept. Any ones thoughts on this please.