A guide to the Type 26 Frigate

As the first of class, HMS Glasgow prepares to begin the fitting out phase of construction, here we take an overview of the Type 26 frigate design. This is a highly complex warship and it is not possible to cover every aspect of the vessel in a single article but this provides a primer on the overall design, weapons and sensors.

Now four decades on from when the highly successful Type 23 frigates were conceived, Type 26 still shares several common concepts with its predecessor. Both are primarily designed for anti-submarine warfare and this requirement dictates the key features of the platform. Their hull form and propulsion system have a low acoustic signature to avoid interfering with passive sonar also makes it harder for submarines to detect the ship. The propulsion systems are very different but retain the ability to ‘sprint and drift’, with gas turbine(s) engaged to enable high speeds and ultra-quiet diesel-electric drive for low speeds and economical cruising. (A much more detailed look at T26 propulsion in the previous article here).

Both have a flight deck and hangar with aircraft handling, refuelling and air weapon handling systems support the Merlin helicopter (or other future rotary wing asset) used to localise and attack the submarine. The key ASW sensor is the towed array sonar comprising an active body and a passive tail, deployed from a winch housed on the quarterdeck. This is supplemented by an active/passive bow-mounted sonar array housed in a fibreglass dome.

T26 can be described as a very large frigate, 149.9m in length with a beam of 20.8m, officially displacing 6,900 tonnes, not far short of the Type 45 destroyer which displaces 7,500 tonnes. The hull has clean lines, with high forward freeboard for good seakeeping and vertical angles avoided to minimise radar returns. Most would agree the overall design is aesthetically pleasing, having the look of a well-balanced warship, although having high proportion of enclosed superstructure.

Active stabilizers are a standard feature of modern combatants and making for a more steady weapons platform and reducing sailor fatigue. The small transom flap at the stern (also retro-fitted to the Type 23s) modifies the distribution of pressure on the after hull, reducing drag, and offers a modest improvement in fuel efficiency, reducing propeller load, cavitation, vibration, and noise.

T26 has a bulky enclosed main mast built from composite materials to reduce top weight, supporting an array of sensors and allowing the primary radar to be sited about 35m above the waterline. T26 is the first RN vessel to have a major structural element made from composites and manufacture was sub-contracted to specialists Umoe Mandal AS in Norway with the masts being delivered to the shipyard in Glasgow by barge.

The T26 has a core crew of 157, but has substantial spare space for another 50 Royal Marines, specialists or augmentees that may be embarked for specific missions. The ship's company will benefit from spacious living accommodation designed from the outset for both male and female crew. Although the T23 has been upgraded over its lifetime and remains highly effective, one aspect that has not proved capable of substantial improvement is the cramped accommodation.

The flexible Mission bay is a major aspect of the T26 design and the first RN combatant designed with this feature. Although allocating a spare space sounds simple, ensuring it can be used operationally and in a variety of ways that may not have even been envisioned yet requires several key enablers. The Mission Bay Handling System (MBHS) developed by Rolls Royce allows containers, equipment or autonomous systems to be self-loaded alongside and deployed at sea. Mission modules need connections to ship's services to supply electrical power, ventilation and air conditioning (HVAC). With a wide variety of boats and bulky unmanned systems, each may require bespoke cradle and fixing systems to secure them tightly to the deck when at sea.

The bay is interconnected to the hangar with a fireproof door and has roll-up doors on each side to protect the space from weather and water ingress. The deckhead of the bay has to be strengthened to provide longitudinal rigidity to the ship, support the MBHS and allow weapons to be mounted on the deck above in future. (See previous in-depth article on the mission bay.)

The 127mm Mk 45 Mod 4 gun and the Mk 41 VLS selected for T26 are both very mature systems but they are new to RN service and will have to be integrated with the combat management system and supporting sensors. The 127mm (5-inch) gun benefits from commonality with several NATO navies and the option of advanced or extended-range munition types. It could also deliver the novel Kingfisher depth charge or sonobuoy rounds (See previous in-depth article on 127mm gun).

The Mk 41 is the most widely used Vertical Launch System in the world and offers the RN the option of purchasing a broad variety of missile types. At the time of writing, only the missile delivered by the Anglo-French Future Cruise and Anti-Ship Weapon (FCASW) programme is certain to be carried by T26 in its Mk 41 cells. This project, now referred to by the RN as the Future Offensive Surface Weapon (FOSW), will provide a supersonic (possibly hypersonic) heavyweight land-attack and anti-ship missile. Officially the Planning Assumption for Service Entry of FOSW will be 2028 in line with HMS Glasgow's IOC although there is some scepticism MBDA can deliver such a complex weapon in that timeframe.

If the RN chose to purchase US missiles, the 24 Mk 41 cells could also be used for VLA (RUM-139B) rocket-launched torpedo system, the SM-3 ballistic defence missile or SM-6 long-range air defence missiles. This seems like a remote possibility due to the cost of the weapons, their integration with the T26 CMS and sensors. Another option would be to quad-pack additional Sea Ceptors into the Mk 41. This would allow T26 to carry a theoretical maximum combined load of 144 missiles.

There is great confidence in the modern Sea Ceptor air-defence missile that has the range to defend a task group and also has a modest anti-ship capability (See previous in-depth article Sea Ceptor). T26 has two, well-separated 24-cell Sea Ceptor VLS modules, one below the bridge and one abaft the funnel. 48 missiles is an increase on the 32 carried by the T23 and reflects the need for the ship to be able to defend itself when operating independently or if providing escort for merchant ships or the carrier strike group.

T26 is rounded out with standard self-defence guns in the form of two Phalanx Block 1B CIWS , two 30mm ASCG together with mounts for a standard mix of force protection .50cal and general purpose machine guns. T26 has sufficient power generation margins to allow Phalanx to be replaced by Directed Energy Weapons when viable operational systems become available in future.

Many will argue the ‘high end’ T26 should have been equipped with a ‘superior’ flat panel AESA radar but instead will receive the rotating Artisan system. Precise details of its performance are not public but Artisan is perhaps underestimated and provides a good balance of capabilities, has a compact antenna, is affordable, is already proven in the RN and has commonality with the T23 and QEC carriers. Its light weight has allowed it to be placed high up, extending the radar horizon.

BAES claim Artisan has a maximum range of about 200km and can detect small objects travelling at Mach 3 more than 25km away. It can track up to 800 objects simultaneously and is highly resistant to ECM and interference. Artisan provides initial target data to Sea Ceptor and can support a salvo (number classified) of missiles in flight via the two-way Platform Data Link Terminals (PDLT).

Until recently, CGI images of T26 showed no less than 5 Ultra Series 2500 Fire-Control Electro-Optical (FCEO) camera mounts but it has subsequently been confirmed that Chess has been contracted to supply 3 Sea Eagle FCEO mounts for each ship instead. The forward mount provides guidance input for the main gun while there is a mount for each 30mm cannon mounted on each side of the hanger. The FCEO cameras are also employed more generally for optical surveillance and identification by teams in the operations room or on the bridge (See previous in-depth article about RN EO mounts).

T26 will have modern EW capabilities delivered as part of the RN's Maritime Electronic Warfare System Integrated Capability (MEWSIC) programme (Increment-1). Details are limited but UAT Mod 2.3 Radar Electronic Support Measures (RESM) receivers will be fitted at the top of the mainmast and the ship will have the Shaman communications electronic support measures (CESM) fit used to gather signals intelligence (SIGINT).

An integrated internal and external communication system will be supplied by Rohde & Schwarz. There are many elements including the Tactical Voice System and Communications Control Subsystem (TACV/CCS), Administrative Telephony and Wireless Communication System (ADTEL/WCS), the internal broadcast and alarms system and self-powered telephones. Military SATCOM (MILSAT), Global Maritime Distress and Safety System (GMDSS), Civil SATCOM, Video Teleconferencing (VTC) will also be integrated. The two configurable pole masts will be manufactured by STS Defence. The starboard mast will predominantly be used for UHF and VHF communications, with 4G, GPS and ship-to-shore satellite communications antennas mounted on the port mast.