DDG-51 Flight IV Future Guided Missile Destroyer
The Navy plans to procure 22 and up to 27 of the AMDR-equipped Flight III DDG 51s between FY2016 and FY2029, designed primarily for IAMD, including ballistic missile defense (BMD). In FY2030, the DON plans to start building an affordable follow-on, multi-mission, mid-sized future surface combatant to replace the Flight IIA DDG 51s that will begin reaching their ESLs in FY2040. The Long Range Shipbuilding Plan for Fiscal Year 2014 issued on April 11, 2013 only indicated that the Navy plans to procure a DDG 51 Flight IV, but does not provide additional information regarding the specifics of this ship, including whether it will be based on a clean sheet design as well as the costs.
Like the Navy’s 2013 shipbuilding plan, the 2014 plan included a future class of destroyers intended to replace the DDG-51 Flight I and II ships when they retire in the late 2020s and 2030s.That retirement date is based on the Navy’s assumption that all DDG-51 Flight IIAs will be modernized midway through their service life and will operate for 40 years. The 2014 plan designates those ships as the DDG-51 Flight IV, consistent with the 2012 and 2013 plans, whereas the 2011 plan used a more generic DDG(X) designation. CBO used the DDG(X) designation because the agency considers it unlikely that the Navy would or could use the DDG-51 design for the next-generation destroyer.
Under the 2014 plan, production of the DDG-51 Flight IV would start in 2030, which would make it a successor to the DDG-51 Flight III program. Some Navy officials have
suggested that the DDG-51 Flight IV could be based on the hull and configuration of the DDG-51 class but incorporate technological improvements appropriate for the late
2020s and early 2030s. According to the Navy, the service would buy 33 DDG-51 Flight IVs at an average cost of $2.0 billion, or about $200 million more than the cost of DDG-51 Flight III ships. Those cost estimates imply that the DDG-51 Flight IV’s capabilities would be a relatively modest improvement over those of the DDG-51 Flight III, and the Navy’s use of the Flight IV designation suggests that it would retain the DDG-51 hull and simply improve the systems on it.
However, the DDG-51 Flight III design consumes almost all available space on the ship and leaves only a small margin for further growth over the life of the ship. Unless the Flight IV systems require less power, weight, and space than the Flight III systems — which would be contrary to the historical trend of improvements to surface combatants requiring more power, weight, and space — then it is not clear that major upgrades to the DDG-51 Flight III constituting a new flight would be possible.
CBO, in contrast, expected that the DDG-51 Flight IV would have a largely new design and would be about 10 percent heavier than the DDG-51 Flight III. By 2030, when the first DDG-51 Flight IV would be authorized under the 2014 plan, the initial DDG-51 design would be about 50 years old. The Navy has made and continued to make improvements to the DDG-51 class, as the plans for Flight III illustrate.
Nevertheless, CBO considers it unlikely that a ship design from the late 1970s and early 1980s would prove robust enough to accommodate changes made to counter threats at sea until the 2070s and 2080s, when the DDG-51 Flight IVs would be reaching the end of their notional 40-year service life. For example, the Navy has limited ability to improve the stealthiness of the DDG-51 class if it does not redesign the hull. If it does redesign the hull, it will, in effect, have created an entirely new ship.
Under those assumptions, CBO projected in 2013 that the average cost of the DDG-51 Flight IV would be $3.3 billion, roughly 65 percent higher than the Navy’s projection. CBO’s 2013 estimate was slightly lower than its estimate of $3.4 billion under the 2013 plan; that difference is the result of increased production rates for the DDG-51 Flight IV in the 2014 plan, which lower overhead costs per ship and also lower direct production costs through greater learning. Over the 2014–2043 period, CBO estimates, the Navy would have to spend $108 billion for this part of its shipbuilding program — $44 billion (or about 70 percent) more than the Navy’s estimate of $64 billion.
The requirements of this ship are in the very early stages of development. These ships will incorporate space, weight, power and cooling margins into their designs and have the flexibility and modularity to host new technologies, however due to their anticipated size they will not include the large array sensors and payloads. Due to the retirement of the TICONDEROGA Class in the Mid and Far Term Periods, the Navy will review implications for the Air Defense Command capability that is vital to the Warfare Command structure of our Strike Groups.
DOD officials stated that no decisions had been made with respect to the capabilities of this future platform, and that Executive Office of the President and DOD decisions may ultimately dictate further analysis on the capabilities needed for future surface combatants. If additional studies were completed and materiel solutions are recommended, DOD officials stated that an AOA may be warranted. Senior Navy officials said that they did not know if Flight IV will carry a larger, more powerful radar or not or what the overall improvements in capabilities will be, even though AMDR is being built with the capability to be scaled up in size.
A major consideration in the future will be electrical power. While Flight III will most likely not leverage technologies developed as part of the DDG 1000 program because of DDG 51’s design constraints, Navy officials stated that Flight IV may carry some form of the integrated power system developed for DDG 1000. The Navy examined the use of the integrated power system for Flight III in the Flight Upgrade Study, but found that it was not currently viable due to current component technology.
The constrained nature of Flight III would likely limit the ability of the Navy to add future weapon technologies to these ships — such as an electromagnetic rail gun or directed energy weapons as these technologies mature — unless the Navy wanted to remove current weapon systems. For example, the ongoing Navy Flight Upgrade Study examined an option to add a small rail gun by removing the ship’s main 5-inch gun and the forward 32-cell missile launcher system. It is unknown when these future technologies may be used.
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