Type 31 frigate: Inspiration class

• Babcock promotes the Arrowyard for the AH140, which serves as a scalable domestic construction solution.
• The Arrowyard encompasses various options for sovereign assembly and construction.
• This arrangement facilitates reduced sustainment costs.

The Type 31 frigates, also referred to as the Inspiration Class, will comprise a total of five vessels: HMS Venturer, HMS Active, HMS Bulldog, HMS Formidable, and HMS Campbeltown. These advanced warships are currently under construction and are projected to be integrated into the Royal Navy fleet by 2030, thereby replacing certain units of the Duke Class frigates.

The Type 31 frigates are intended to enter service within the 2020s, functioning alongside eight Type 26 frigates, which are specialised for submarine detection and will succeed the five general-purpose Type 23 frigates. This initiative is part of the United Kingdom government's "National Shipbuilding Strategy."

The design of the Type 31 frigates has been developed by Babcock International and is based on the hull of the Odense Maritime Technology (OMT) Iver Huitfeldt-class frigate, marketed under the name Arrowhead 140. Additionally, the design has been sold to Indonesia, resulting in the creation of two ships known as the Fregat Merah Putih ("Red-White frigate") in September 2021, as well as to Poland for the construction of three vessels categorised as Wicher-class frigates in March 2022.

As part of the government’s 2030 vision, the Type 31 frigates aim to prepare the three branches of the United Kingdom’s defence forces to effectively address a diverse range of threats. The development of these vessels is aligned with the UK’s revised National Shipbuilding Strategy, which seeks to enhance national naval shipbuilding capabilities.

The steel-cutting ceremony for the second frigate, HMS Active, was held in January 2023, with the ship's keel being laid in September 2023. These new warships are anticipated to enter service by 2028 and will operate in conjunction with the Type 32 and Type 26 frigates, which are specifically designated for submarine detection missions.

Development

The 2010 Strategic Defence and Security Review (SDSR) was pivotal for the Royal Navy, introducing the Global Combat Ship (GCS) program aimed at replacing the ageing Type 23 frigates. In early 2010, the Ministry of Defence awarded BAE Systems a £127 million contract for the design and development of a new class of warships to modernise naval capabilities in line with the UK’s evolving defence needs.

The planning phase anticipated two main variants of the frigate: five general-purpose frigates with versatile capabilities and eight anti-submarine warfare frigates designed to counter underwater threats, distinguished primarily by the advanced Sonar 2087 system for anti-submarine operations.

Initially, construction was slated to begin in 2016, with new vessels expected to gradually replace the Type 23 frigates by the mid-2030s. However, the 2015 Defence Review shifted the focus towards solely finalising orders for eight anti-submarine warfare Type 26 frigates.

The General-Purpose Frigate (GPFF) was developed in response to needs identified in the Defence Review, designed as a lighter and more cost-effective class of frigates for various operational roles. The 2015 SDSR suggested that these new frigates could enable the Royal Navy to acquire more units than originally planned, enhancing maritime security and operational readiness.

In July 2016, Admiral Sir Philip Jones, First Sea Lord, presented the GPFF as the Type 31 frigate, highlighting its suitability for operations in strategically significant areas from the Persian Gulf to the Asia-Pacific region. BAE Systems introduced two potential designs for the GPFF: the "Avenger class," based on the Amazonas-class/River-class Batch 2 offshore patrol vessel, and the "Cutlass class," an improved version of the Al Shamikh-class corvette.

Admiral Jones described GPFF as “a much less high-end ship,” though still a complex warship capable of protective and defensive roles globally. The design approach prioritised lessons from the defence industry and off-the-shelf technologies, making the ship more appealing for lower-tier Royal Navy missions.

In September 2017, the Royal Navy showcased the modular adaptability of the Type 31e design, with essential features including a medium-calibre gun, point-defence systems, a hangar, and a flight deck for a Wildcat or a ten-tonne helicopter. The frigate was designed for a crew of approximately 100 personnel, with the capacity to accommodate an additional 40 for specific missions.

Design

The design of AH140, submitted by Babcock, BMT, and Thales, represents an advancement of the Iver Huitfeldt-class frigates currently in operation within the Royal Danish Navy.

This Type 31 platform has undergone extensive redesign from its parent class to comply with Lloyd’s Register Naval Ship Rules, in contrast to the Det Norske Veritas (DNV) regulations applicable to the original class. Furthermore, the Type 31 has been tailored to meet the NATO ANEP-77 Naval Ship Code as well as stringent UK naval stability requirements. This redesign is part of a comprehensive effort to ensure adherence to the UK DefStan 02-900 General Naval Standard and a range of other UK naval standards.

Key features of this design include a stern boat ramp connected to an existing mission bay located beneath the flight deck, a side hydraulic ramp, and an expanded hangar accommodating up to two AgustaWestland Merlin AW101-sized helicopters. This hangar is directly linked to a full-width mission bay that replaces the previously established 32-cell Vertical Launch System (VLS) complex amidships, allowing the support of up to three 11-meter craft, including unmanned surface vehicles and rigid inflatable boats, as well as containers.

The frigate design offers substantial space to facilitate potential future upgrades to its sensor and weapon systems. The latest iteration of Thales’ TACTICOS combat management system, which features an open architectural design, will be integrated into the Type 31 frigates. Accompanying this is a comprehensive in-service support package aimed at maximising combat system capabilities for users. Additionally, the frigate will incorporate onboard systems, including a SharpEye navigation radar, Mirador Mk2 electro-optical systems, and Vigile-D digital electronic support measures.

An ultra-high frequency (UHF) satellite communications (SATCOM) system is to be integrated into the frigate to ensure reliable voice and data communications at sea. This system will provide secure, beyond-line-of-sight communications for the Inspiration-class ships.

Moreover, the frigate will feature the Synapsis Naval Warship Integrated Navigation and Bridge System (WINBS), characterised by modern solutions for integrated navigation. This system, enhanced with AI-based technology, will include naval radars, both automatic and manual steering control systems, communication systems, and a complete array of navigational and tactical sensors.

Each Type 31 ship is projected to measure approximately 140 meters in length, with a displacement exceeding 5,700 tonnes and the ability to accommodate 105 crew members. The new warship showcases a unique modular design that allows for various configurations to meet the operational requirements of the Royal Navy as well as allied naval forces globally. The baseline design offers a contemporary and versatile naval warship solution for the Royal Navy.

Flexibility in customisation is a prominent feature of this design, which allows for the incorporation of an open architecture combat system, bridge wing modules, and adaptable mission bays. The design also features electrically actuated assemblies instead of hydraulic systems. The AH140 design provides significant flexibility in component systems, permitting the installation of various radar masts (both fixed and rotating), up to four boat bays for rigid-hulled inflatable boats (RHIBs) or small unmanned surface vehicles (USVs), and customisable options for medium and small calibre gun systems (up to 127 mm in Position A and up to 76 mm in Position B).

Several vertical launching systems (VLS) configurations are available; these include a 24-cell CAMM "mushroom farm" configuration, which offers a cost-effective and weight-efficient solution, and a 32-cell strike-length Mark 41 VLS for long-range surface-to-air missiles (SAMs) or surface-to-surface missiles (SSMs), which can be installed amidships. Additionally, by removing the gun mount from Position B, an extra 16-cell Mark 41 complex can be positioned forward of the bridge, allowing for either a total of 48 cells or a reallocation of space in the central sections for alternative facilities, such as a full-width mission bay. Previous renderings of the Red-White frigate design for Indonesia also indicate the potential addition of an extra 56 cells of an unspecified type behind the main gun, suggesting a substantial degree of weapon customisation is feasible.

Furthermore, a noteworthy aspect of the AH140 design is its dedicated accommodation capacity for more than 180 personnel while necessitating a crew of less than 100. This arrangement facilitates reduced sustainment costs and provides ample provisioning for mission-specific personnel, including flight crews, remote system operators, and specialised military units.

Thoughts

Babcock promotes the 'Arrowyard' for the AH140, which serves as a scalable domestic construction solution. According to Babcock’s marketing communications, it "offers a highly capable, cost-effective, and tailored approach that enhances quality and performance, thereby providing a competitive advantage in international shipbuilding." The Arrowyard encompasses various options for sovereign assembly and construction, ranging from a basic outfitting yard where large ship components are delivered and assembled to a fully vertically integrated facility capable of constructing an entire vessel from fundamental steel materials on-site. The Arrowyard is a crucial component of Babcock's business strategy for the AH140, focusing on Indigenous design to cultivate secure relationships with exporting nations and their associated industrial and societal frameworks.