Modularity: What our partners are doing to build future-focused navies

The Royal Navy’s pursuit of capability adaptability should re-assure our own defence policy makers that modularity is worth investigating, writes maritime capability specialist and former Royal New Zealand Navy Officer Andrew Watts.

Historically, navies have attempted to acquire combatant ships permanently equipped and trained to defeat threats in all dimensions. The escalating cost of such platforms is now forcing even the largest and most advanced navies to consider alternatives. As discussed in an earlier article (“Modularity and the Shape of New Zealand’s Next Naval Fleet”) published in Issue 22 of Line of Defence, the most promising of these alternatives is ‘capability modularity’.

Capability modularity involves the adoption of platforms that can be fitted with removable self-contained capability modules tailored to specific types of operation. The number of platforms acquired can be determined by the number of operations of all types that a given fleet is expected to undertake at any one time, allowing for maintenance and respite. The number and type of capability modules acquired is dependent on the number and type of missions that the fleet is expected to undertake concurrently.

A modular capability concept could achieve the following:

• A force structure that is adaptable at short notice across a much wider range of missions than one based on platforms permanently optimised for a particular function.

• A fleet which as a whole is much more likely to be available for a wide range of missions, including the protection of shipping in the approaches to New Zealand and major international shipping routes in conjunction with our partners.

• The acquisition of platform capability independent of acquisition decisions around mission capability. For instance, modular platforms could be designed to be compatible with advanced capability without the need to commit to buying the modules until the need becomes apparent.

• Standardisation on common platform systems, reducing sustainment costs, simplifying work force training and management by reducing system specialisation, and reducing and simplifying supply chains.

• Future proofing – obsolescence would be addressed by upgrading or replacing capability modules while platforms remained in service. Loss of availability such as that required by the Frigate System Upgrade project would be avoided – together with the cost and schedule risks that are part and parcel of such upgrades.

• Expandability – should future assessments point to a need to provide direct protection to shipping in the approaches to New Zealand (for example), it may be possible to acquire more ASW modules and equip more platforms for the protection of shipping.

• Greater efficiency in work force management. Only those people required for essential common functions would be permanently linked to platforms. Others would be linked to modules and would only be required to go to sea when their modules are required for training and operations. Making this work would require a number of highly complex problems to be solved, but nonetheless it must be considered.

• The early and cost-effective adoption of autonomous vehicle technology. Autonomous capabilities are well adapted to modularity and offer step change increases in capability, especially in surveillance heavy missions such as ASW, MCM and the building of MDA. Autonomy also reduces work force requirements and the need to put people in dangerous proximity to threats.

Adaptable Strike Frigate at sea. Image: BAE Systems.

What is the rest of the world doing?

There has always been a distinct aversion to early technology adoption amongst New Zealand defence policy makers, and with good reason. Early iterations of new defence technologies tend to be both expensive and risk prone; New Zealand cannot absorb the consequences of technology failure in the way that nations able to fall back on larger force structures can.

It is therefore reasonable for policy makers to ask whether an acquisition strategy based on capability modularity would fall into that high risk category, and to ask what our partners are doing to adopt and thus de-risk the modularity concept.

Firstly, if modularity is a viable alternative to traditional multifunction combatant concepts, why are our main partners still acquiring the latter? The answer to this lies partly in the very long gestation period for almost all types of naval capability.

The Royal Navy’s Type 26 frigate (adopted by Australia and Canada as the basis for their requirements) was conceived in studies initiated in the late 1990s, but the first ship will not enter service until 2026. As capable as these ships undoubtedly are, their basic concept was fixed some time ago – well before modularity as a capability concept had matured to a point where it could be considered for critical front line combatants.

Additionally, acquisition decisions must take into account a variety of considerations, not all of which relate directly to capability concepts.

For example, the Australian government determined that a regular naval shipbuilding drumbeat was essential to defence selfsufficiency. Concurrently, there was an economic need to make up for the loss to the economy of the defunct automotive manufacturing sector. Timing considerations meant that the choice for the future frigate programme was limited to existing designs that could be adapted to Australian needs relatively quickly.

None of the contenders featured modularity as a central design concept, although the Type 26 design selected does incorporate a degree of modularity for ancillary missions, as do most other new and emergent NATO surface combatant classes. Ancillary function modules include medical, special forces support, command and control and autonomous vehicle capability.

The United States has truncated the modular Littoral Combat Ship (LCS) programme and adopted a traditional multifunction combatant design (FFG(X)) to make up the balance of its “small” surface combatant fleet requirements.

Vice Admiral David H. Lewis, USN (Retired), a former Commander of the US Space and Naval Warfare Systems Command and Deputy Commander of the US Naval Sea Systems Command, commented in a paper in Issue 1, Volume 5 of the US Naval War College Review that:

“The derivative USN FFG(X) war-fighting requirements themselves were developed between 2016 and 2017 to support a planned delivery of the first ship in 2028. Thus, by the time the twenty-ship class is completed in the 2030s, it will be a thirty-twoyear-old design filling a twenty-twoyear-old war-fighting requirement, with little capacity to accept 2040s capabilities or be modernized to address contemporary war-fighting requirements…”

Admiral Lewis’ theme is that the US Navy must adopt what he refers to as open architecture surface warfare design in which mission payload is de-coupled from platforms in order to remain relevant and effective into the future.

HMS Glasgow under construction in June 2021. Image UK Ministry of Defence.

Just as aircraft carriers remain relevant over 50 plus year service lives because they are capable of embarking successive generations of aircraft as they are developed, so surface warships must be designed to embark capability, as opposed to being fitted with it. He cites the Danish STANFLEX concept as an exemplar of what has already been achieved, and LCS as a seemingly lost opportunity.

The decision to truncate the LCS program was not due to the failure of the modularity concept. LCS appears to have fallen short on the value for money front, with the costs of the platforms and capability modules greatly exceeding original estimates. LCS also featured unusually demanding requirements around speed and minimal crew numbers, which together with a compressed development timetable appears to have compromised both performance and availability.

However, the US Naval Sea Systems Command is investing heavily in modularity trials programme. Modular capability will almost certainly be a feature of next generation US fleets.

When it comes to modular concepts for primary as opposed to ancillary capability, the Royal Navy appears to be in the lead. The Type 31 frigate, designed and built to an exceedingly tight budget, will incorporate the containerised Persistent Operational Deployment System (PODS). A large number of potential PODS modules are under development or consideration, including C2, mine countermeasures, precision strike, hydrographic survey, and intriguingly, a “factory” module for the rapid prototyping of autonomous vehicles and equipment repair.

The range of capability potentially offered by PODS will likely exceed that of other current combatant designs, but Type 31 does not feature the primary mission adaptability that was the topic of my original article and which I believe offers the most promise for the next generation RNZN fleet.

The Royal Navy is also developing the follow on to the Type 31 frigate, the Type 32. The backdrop to the development of Type 32 is provided in the following extract from the Royal Navy’s Maritime Operating Concept, released in September 2022:

Danish Navy Thetis-class frigate HDMS Thetis and Flyvefisken-class patrol vessel HDMS Skaden use StanFlex modules. Image: Wikimedia Commons user Heb.

“A Protean Maritime Force is one which is fundamentally balanced and possessed of an innate adaptability. Taken further, the Protean Maritime Force is a move away from highly specific platform optimisation towards a force with interdependent and interchangeable system components. It is a force comprised of multiple scalable and flexible systems, organised and orientated for effect not activity. Being Protean by design best positions the Maritime Force to capitalise on disruption – technological, environmental or situational. It increases choice and the utility of the Maritime Force…”

This intriguing statement is expanded on later in the document: “…by breaking the link – and by implication the traditional model – between platforms and capabilities, a System of Systems approach increases the scope for capability and technology insertion, increasing agility and ultimately contributing to operational advantage. Achieving this is a behavioural challenge. If done half-heartedly or haphazardly, then considerable additional effort is needed later to enable the systems and capabilities to fit into the System of Systems approach..”

Finally: “The contemporary Royal Navy is a force designed around platforms – ships, submarines, and aircraft – which have distinct and sometimes singular purposes. This current highly capable platform centric approach is becoming increasingly unaffordable. Taken in combination, a Maritime Task Group may be potent across all sub-domains, but it was not designed with interdependency, modularity, distribution or to be protean in mind from the outset…”

The concepts articulated in the Maritime Operating Concept were foreshadowed in the 2020 Integrated Review, and although a formal requirement for Type 32 has yet to be issued to industry (the project entered the concept phase in October 2022), BAE Systems has produced a concept called the Adaptable Strike Frigate. The concept is roughly the same size as Type 31 (140m, 6,000 tonnes), with a forward section resembling traditional surface combatants with a medium calibre gun and a vertical launching system for various types of missile.

The after section, however, is dedicated to a wide range of capability modules, including Anti-Submarine Warfare (ASW) systems. The BAE Systems concept thus aligns with the primary mission adaptability aspiration articulated in the Maritime Operating Concept, which I suggest is that which offers the greatest potential for our own future naval capability requirements. To return to the point with which this article began, the fact that the Royal Navy is pursuing capability adaptability and thus modularity to such an ambitious extent should re-assure our own defence policy makers that capability modularity is worth investigating, which is the main point of this article. Leveraging our strong relationship with the Royal Navy to develop a deeper understanding of modularity potential, and exploring possible cooperation on the Type 32 requirement, might pay major dividends.

In an over three-decade career in the RNZN, CAPT Andrew Watts RNZNR commanded HMNZ Ships Pukaki, Wellington, Resolution and Te Mana, and served as Director, Capability Development and Programme Director Network Enabled Capability, and Captain, Fleet Personnel & Training. He is a Defence Adviser at KPMG based in Riyadh.