Constellation-class: the US Navy’s struggle to forge a new generation of frigates
After the perceived failure of the Littoral Combat ship programme, the US Navy has shifted its focus back to building traditional frigates. In this piece, we examine the turbulent beginnings of the Constellation-class (FFG-62) project and look at the wider lessons for those involved in warship design and acquisition.
Background
In the early 21st Century, a faction in the US Navy believed that conflict with another peer state was becoming a remote possibility and the main concern was terrorism and a few rogue states. In this new world, ‘old-fashioned’ frigates were seen as obsolete and should be replaced by something more agile and exciting. With the highly successful Oliver Hazard Perry-class frigates in need of replacement, instead of developing a new frigate, the radical Littoral Combat Ship was chosen.
The LCS was intended to be light, fast and modular, able to adapt to different roles and optimised for asymmetric warfare in coastal waters. Without getting into the conceptual flaws, design issues and procurement mistakes, the programme has mostly proved to be a disaster. Having spent $billions, the USN is stuck with more than 30 ships with a mix of reliability issues, poor survivability and missing capabilities. While some have already been decommissioned, the USN is working hard to overcome their shortcomings and optimise them for their main utility in the surface strike role. Perhaps most significantly, the intended ASW mission package for the LCS has been cancelled.
The USN has continued to buy more of the excellent Arleigh Burke-class destroyers (a total of 117 likely to be built, now on the Flight III variant). Based on a 1980s design, these ships have continually evolved but are now at the developmental limit of what can be done within the existing hull. Burkes form the backbone of the fleet and are exceptionally capable air defence assets but they are not the best ASW platforms.
Now all retired from USN service, the Oliver Hazard Perry-class were simple and effective frigates built in large numbers from 1977 to 89. The design was exported to several global navies with many still active.
FFG(X)
Finally recognising the need for conventional frigates, the FFG(X) program became public in 2017. To (theoretically) control costs and expedite delivery, the USN looked for a proven frigate design as a starting point. Breaking with two centuries of tradition, a foreign capital ship design was selected as the basis of FFG(X) – the Italian ASW variant of the Franco-Italian FREMM (Fregata Europee Multi-Missione). In 2020 Fincantieri was awarded an $800M contract for detailed design and the construction of the first ship at its Marinette shipyard in Wisconsin. The lead ship of the class will be named USS Constellation (FFG-62) and a further 5 ships are now on order, with the intention to eventually acquire at least 20 vessels.
The Constellation will be very different to the FREMM. The principal features of the class are the AEGIS Baseline 10 Combat System, the AN/SPY-6 AESA 3D primary radar and a 32-cell Mk41 VLS. No less than 16 Naval Strike Missiles will be carried in canister launchers amidships. In common with the RN Type 31 frigate, the main gun will be the lightweight Mk 110 57mm. Point defence will be provided by the MK 49 RAM Block III system. There will be no hull or bow-mounted sonars but instead, the USN will fit the highly effective Thales CAPTAS-4 towed array sonar that is also the basis for the RN’s type S2087 system. The hangar and flight deck will support a single MH-60R Seahawk ASW helicopter and/or future RWUAS.
Constellation will use a heavily modified version of the Combined Diesel-Electric and Gas (CODLAG) propulsion of the FREMM. The single LM2500+G4 Gas Turbine is common to both but the US will use more powerful diesel generator sets and electric motors, design a new gearbox, shaft lines, propellers and machinery control system. To maintain the low acoustic signature needed for ASW, the design and manufacture of these components needs to be especially rigorous. The USN is committed to building a Land Based Engineering and Test Site (LBES) to de-risk the propulsion and combat system before fitting into the ship.
The principal features of the Constellation class.
Customisation costs
Initially, the project seemed like the USN would be getting a series of fine ASW frigates with good all-round performance at less than £1bn per ship. Unfortunately, this optimism soon disappeared as Naval Sea Systems Command (NAVSEA) and its subcontractors, Gibbs & Cox began to make major changes to the FREMM parent design. The hull has been lengthened by 23.6 feet to accommodate larger diesel generators to support future equipment fit and give an increase in speed to allow the ships to keep up with carrier battle groups steaming at 30+ knots. The bow design was substantially modified to make space for 32 Mk41 VLS cells and the bow sonar was removed to improve speed and seakeeping. The value of hull-mounted sonars are the subject of debate but feature on most ASW frigates. It is not always possible to stream the towed array and HMS are useful for short-medium-range detection and can provide warnings of torpedoes and mines.
With the exception of LCS, the USN has markedly higher survivability standards than most European navies. This includes ballistic protection, water-tight subdivision, firefighting systems, redundancy and revisionary modes for weapons and critical systems. Internal modifications to meet a completely different set of standards requires a significant amount of new design work and has added at least 300 tons of weight to the ship.
Superstructure mass has been reduced and the topside arrangement substantially changed to accommodate US combat systems. The selection of systems already in service should reduce engineering risk but there is still some novel integration work to be done including CAPTAS-4 which is new to the USN. However well-proven, all of this equipment has to be integrated into the design and has little in common with that fitted to the original FREMM.
FREMM V Constellation. ITS Virginio Fasan has minimal resemblance to the latest rendering of the Constellation class.
Initially, the Constellation design shared about 85% commonality with the parent design but the modifications have now reduced this figure to below 15%, almost an entirely new ship. During a design review, it was found the revisions meant the hull was not now stiff enough longitudinally, requiring additional reinforcement. Total displacement has increased by around 500 tons but by October 2023 the US Government Accountability Office (GAO) reported further unplanned weight growth of over 10% above the shipbuilder’s initial weight estimate. Costs have also spiralled with the latest price for each ship around $1.6bn, a 40% increase on the original estimate.
Unlike many European navies that are more used to compromises and de-scoping projects to keep within tight budgets, the US Navy has historically been able to dictate most of its requirements and frequently accept major cost overruns. The USN issued 511 functional design documents referred to as the contract data requirements list (CDRL) for the FFG-62 and these rigid specifications have driven complexity, delay and cost into the programme. In February 2024 it was reported 343 CDRL items had not yet been approved.
To complicate matters further construction work on the lead ship has already begun before the detailed design work has been completed for many aspects of the vessels. This practice of ‘concurrency’, which gives the impression of progress, usually leads to complications and delays (infamously a policy implemented for the F-35 programme) as re-work, late modifications or back-fitting is required.
The Fincantieri Marinette Marine Shipyard is also struggling with labour and supply chain issues. Particularly since the pandemic, the US shipbuilding and repair sector has suffered from recruitment and retention problems, together with raw material costs rising sharply. FMM also has a significant backlog of work on the tail end of the LCS program and LCS on order for Saudi Arabia. Consideration is now being given to involving a second shipyard for the Constellation programme.
All these issues have culminated in the USN recently admitting that delivery of USS Constellation will now be delayed by 3 years.
FFG-62 arrangement compared with the Italian FREMM design (blue silhouette). Note the addition of a retractable azimuth thruster to enhance low-speed manoeuvrability and to provide emergency propulsion.
Perfect is the enemy of good
There is a good argument that the USN’s uncompromising approach to the Constellation class is to maximise capability and ensure the safety of its sailors. The alternative view is that just when the USN needs more affordable lower-end combatants in good numbers as quickly as possible its decisions to ‘gold-plate’ will cause delays and reduce fleet size. There is a balance to be struck and it is a matter of fine judgement. The RN’s Type 31 programme is controversial but is an example of making a compromise on capability in order to get ships within a given budget and timeframe.
There are those in the US pushing to see the Constellations further up-armed. Unhappy with just 32 VLS cells they would like to see the ship enlarged to carry 48. Besides adding further cost and delay, this kind of mission creep slightly overlooks the frigate’s primary ASW mission (while having good all-around capabilities that allows it to operate independently or as part of the carrier group). The USN needs to increase overall firepower but there are other routes to achieving this. Besides, without the best tools to achieve mastery over the underwater domain, the whole fleet is at risk.
USS Zumwalt and USS Independence – poster children for the US Navy’s missteps in surface combatant design. The DD(X) was a case of technical over-reach while Littoral Combat Ships have proved underwhelming. The US needs to recover its ability to design and deliver effective and affordable warships.
Warship procurement – never easy
From a European perspective, the difficulties the USN has experienced in procuring new surface combatants are all too familiar and of very serious concern. Declining USN hull numbers has major implications for the strength of NATO. Despite years of warnings and small steps toward European rearmament, NATO would still be heavily reliant on the USN to do much of the heavy lifting in the case of direct conflict with Russia.
The challenge from China also intensifies the consequences of US industrial and procurement failures. Total US and European combatant construction combined is comfortably being outpaced by the Chinese. The PLAN fleet is expanding rapidly and in 2023 alone commissioned 8 Type 054A frigates and launched two much-improved Type 054B variants, never mind many other warship and submarine types.
There were advocates in the US for selecting the RN’s Type 26 as the basis for FFG(X) but it was outside the parameters of the competition that specified a platform proven in service. The selection of a design already at sea was, quite reasonably, seen as a way of reducing engineering risk. However, given how extensively the USN has subsequently modified FREMM, this risk has effectively been added back into the programme. With hindsight, the Type 26 might have proved easier to adapt, given its larger hull capacity (c 1,000 tonnes) and higher survivability standards closer to US practice. It would also have given the USN commonality with its two AUKUS partners.
The Australian Navy has encountered difficulty adding significant extra air defence capability for its Hunter class to the ASW-focussed Type 26 platform. In contrast, the latest iteration of the Type 26-based Canadian River-class looks well-balanced and will be predominantly equipped with US-made combat system, making for an interesting value-for-money comparison with the Constellation. The propulsion system of neither the Hunter nor River class has been significantly modified and the platform comes with additional power generation margins to support future equipment fit.
The early signs for the Constellation programme are not encouraging but naval procurement is never easy and few nations outside of East Asia seem able to consistently deliver effective warships on-time and on-budget. Delay and cost increases are now unavoidable but let us hope that once the design and shipyard issues are resolved, production will settle down into a steady drumbeat of deliveries. The success of Constellations will play a key part in determining if the USN can reach its goal of a 500-ship force while the need for more hulls and improved ASW capability has never been more pressing. Source: Navy Lookout (04/09)
AGS