With memories of the Zumwalt-class (DDG-1000) destroyer’s spectacular failure still fresh, the US Navy is taking another stab at developing a 21st-century large surface combatant. Naval Sea Systems Command (NAVSEA), the entity responsible for designing, procuring, and maintaining the Navy’s ships, recently issued Requests for Information (RFIs) related to a new surface warship program, Large Surface Combatant (LSC). The Navy uses the term “large surface combatant” (note lowercase) in reference to all destroyers and cruisers, but Large Surface Combatant is a distinct class and will serve alongside the Small Surface Combatant (FFG(X)), which is due to enter service during the 2020s.
RFIs represent an early stage in the procurement process and are used to help formulate requirements. As such, programs remain quite fluid during the RFI phase; the Navy could go in any number of directions based on the results of its studies and the feedback it receives.
Uncertainty notwithstanding, the RFIs shed light upon the Navy’s overarching goals for the program. Two RFIs were issued by NAVSEA, one for shipbuilders and one for systems providers. Of course, only Huntington Ingalls Industries (HII) and General Dynamics (GD) are capable of building large surface warships like LSC. In all likelihood, construction work on LSC (if it comes to fruition) will be divided amongst HII and GD to keep both shipyards open and healthy.
The words “destroyer” and “cruiser” are conspicuously absent in the RFIs; this reflects the Navy’s Future Surface Combatant Force concept, which envisions a fleet of “large” and “small” surface combatants. In the RFIs, NAVSEA mentions that LSC should have dedicated space for the air warfare commander, implying that LSC will take over the command role currently assigned the Ticonderoga-class cruisers (regardless of whether they end up designated as such).
Like many recent DoD procurement efforts (notably JLTV, OMFV, and FFG(X)), the LSC RFIs emphasize maturity and risk mitigation. For example, they suggest that LSC will use many of the Flight III Arleigh Burke’s sensors and combat system — a logical choice given that Flight III Burkes employ state-of-the-art electronics. Similarly, the RFIs repeatedly advocate “non-developmental” technologies to keep costs and risk under control.
Nonetheless, it is clear that LSC will not be a repackaged Arleigh Burke hull with extra room for the air warfare commander. The Navy’s wishlist includes items that will require inventive engineering solutions and advanced technologies not seen aboard previous American surface combatants.
Perhaps most importantly, increased firepower: the RFIs mention incorporating larger VLS cells in order to field “longer and larger diameter missiles.” The current Mk 41 VLS’ weapons already boast impressive ranges (1,000 nmi+ for the Tomahawk Land Attack Missile and ~200 nmi for the anti-air Standard Missile 6), so this interest in enlarged cells is noteworthy and may be related to ongoing efforts in the hypersonic (and counter-hypersonic) realm. Weapons programs take a fair amount of time and, to my knowledge, no VLS-launched missile requiring a larger diameter than the Mk 41 is currently under development. As such, the roomy VLS cells are likely for future growth rather than meeting an immediate requirement.
Indeed, growth and evolution are a key theme in the RFIs. This reflects a broader trend towards modularity and open architectures, which allow for incremental upgrades and the injection of new capabilities without major overhauls. Power generation and cooling are repeatedly mentioned, which should come as no surprise. Spare electrical and cooling capacity allow for continual systems upgrades, which are essential for keeping platforms relevant throughout their service lives. And, of course, the Navy also mentions directed energy weapons (DEWs) and railguns, which are often touted as the surface Navy’s future “ace in the hole” so to speak. Though still relatively immature, the RFI places a fair deal of emphasis on these novel technologies (especially DEWs), going so far as to list 360-degree DEW coverage as a potential baseline requirement.
In order to power these exotic systems, the Navy is considering an integrated power system (IPS). The current Ticonderoga and Arleigh Burke classes use traditional mechanical drive shafts and LM2500 gas turbines for their propulsion; separate diesel generators provide electrical power. An IPS, in contrast, eliminates mechanical drivetrains by using generators mated to a unified electrical system. Power is distributed via high-voltage wiring to all the ship’s systems, including electric motors for propulsion. An IPS has a number of benefits, including reduced sound signature, increased efficiency, flexibility in the placement of powerplants, and good expandability. Some main drawbacks are up-front cost and technical risk — an IPS requires high-voltage, high-amperage transmission equipment and is generally more difficult to implement than a traditional drivetrain of comparable performance.
Thus far, IPS’ track record aboard surface combatants has not been particularly illustrious. The Zumwalt-class destroyer, which dramatically overran cost estimates and ultimately incurred a Nunn-McCurdy breach, uses IPS, as do the Royal Navy’s Type 045 destroyers. The latter have experienced a number of IPS-related issues, affecting operations and requiring significant remedial modifications.
As such, it is unsurprising that NAVSEA wishes to hear industry’s input before making an IPS a baseline requirement. It seems likely at this stage that IPS will be adopted, although China’s Type 055 destroyer — with its traditional gas turbine propulsion setup and six 5 MW generators — proves that robust power generation does not necessarily require an IPS.
Reduced signatures are another area of interest, especially in the shipbuilder RFI. The Zumwalt class makes extensive use of radar cross-section (RCS) reducing measures such as a mast-less superstructure, atypical tumblehome bow, and smooth, flush surfaces. Some media outlets are citing commentary by Admiral William Gallanis as evidence that LSC will have the same hull form as the Zumwalt class, but the RFIs do not (in my opinion) support this notion. Gallanis mentioned “deckhouse hull form” when discussing potential similarities between the LSC and Zumwalt, not bow and overall hull shape. My impression is that Navy officials do not desire Zumwalt levels of stealth (which proved quite expensive) but rather moderate signature-reduction measures similar to the FREMM-class frigate or the Legend-class cutter.
To conclude, the LSC RFIs, though not necessarily indicative of the final requirements, provide an early look at the Navy’s vision for a large, advanced surface combatant to replace the Zumwalt class. NAVSEA wants a ship capable of hosting the air warfare commander and deploying advanced weapons that have yet to be perfected. It should be highly upgradeable but not incorporate too many cutting-edge features that would drive up cost. The class will likely be equipped with many existing systems — including the SPY-6 radar — from the Flight III Arleigh Burke, and will incorporate some features seen on the Zumwalt class, including reduced signatures and (likely) an integrated power system. However, it will not represent as extreme a departure from orthodox surface combatant design as the DDG-1000. These insights from the RFIs align with what Navy officials have publicly said about their vision for LSC and naval warship procurement more broadly.
Whether LSC lives up to its potential will depend on the Navy’s developmental weapons programs. If directed energy weapons, railguns, and large-diameter/hypersonic missiles cannot be fielded during the ship’s service life, LSC may end up as a larger, more costly, slightly more stealthy Arleigh Burke. That is a problem not because the Arleigh Burke blueprint is flawed but because anti-ship technologies are rapidly advancing; in order to overcome increasingly-sophisticated adversary capabilities, the US Navy needs a leap forward in weapons performance, not more of the same. LSC can provide a platform for those next-generation systems, but only if they materialize.
And even if progress on directed energy, railguns, and other exotic weapons continues apace, LSC’s future will be influenced by debates surrounding the Navy’s force structure. At the moment, large surface combatants (cruisers and destroyers) are the most numerous oceangoing platform in Navy service; apart from the Littoral Combat Ships and a handful of Cyclone-class patrol ships, the entirety of the Navy’s surface combatant force is comprised of >8,000-ton destroyers and cruisers.
Many critics object to this emphasis on large, costly vessels, which represent a huge investment in terms of money and manpower; a typical destroyer or cruiser has a complement of 300+ sailors, costs almost $2 billion to procure, and is quite expensive to maintain. The loss of even one such ship in conflict would be a serious incident. Instead of continuing to prioritize large vessels, many believe the Navy should begin to dis-aggregate its capabilities, placing a substantial portion of its firepower on smaller ships and fielding unmanned vehicles to operate in high-risk areas where survival cannot be guaranteed.
Recent comments indicate the Navy is taking distributed firepower seriously. In a hearing, Vice Admiral Bill Merz told members of HASC that the Navy’s new Force Structure Assessment, due for publication later in 2019, will emphasize distributed capabilities and call for fewer large surface combatants.
Interestingly, this runs counter to the Navy’s most recent (FY20) shipbuilding plan, which sees the service achieving its 355-ship objective by expanding the large surface combatant fleet to over 110 ships. The plan calls for producing two to three LSCs each year beginning in FY26, a rate roughly equivalent to current Burke class production. Obviously, a tempo of LSC production this high would not correspond to a decreased emphasis on large surface combatants — in fact, quite the opposite.
Shipbuilding plans are constantly in flux and incorporate a great deal of wishful thinking; after all, Congress is ultimately responsible for funding the military, and its appropriations are not predictable on the timescales covered by the plan. Force structure assessments, on the other hand, represent the Navy’s most recent concepts of operations and tend to carry a fair deal of weight. As such, one can expect the upcoming FSA to largely override the FY20 shipbuilding plan. If the FSA calls for a reduction in large combatant emphasis, the 2-3 per year LSC procurement rate cited in the FY20 will come under fire, which could threaten some of the industrial capacity built up during Flight IIA and III Arleigh Burke production. Congress is generally loath to cut funding for major projects like LSC, which provide a large number of well-paid constituent jobs. As such, LSC seems poised to become a subject of substantial controversy going forward.