Report: Cost spike for Navy’s next DDGs

The Navy could pay almost double for a new ship originally planned as a way to save money.

The Navy may not realize any savings from copying the existing design of its workhorse destroyer for a new version of the ship, according to a report Wednesday — in fact, the new DDGs may end up costing billions more.

Sam LaGrone of Jane’s Navy International writes that according to the latest projections, the new Flight III versions of the Arleigh Burke-class destroyer could cost between $3 and nearly $4 billion apiece, as much as double today’s Flight II version. That’s despite Navy officials’ onetime belief that restarting production of DDG 51s made sense because it would save money as compared with their previous planned run of next-generation Zumwalt-class destroyers.

Why might the new ships cost so much more? Because building a Flight III Burke isn’t the equivalent of just slapping a Lincoln badge onto a Ford, as LaGrone wrote:

The Flight III destroyers will field the result of the Hull and Radar Study: the Air and Missile Defence Radar (AMDR). With a planned aperture of 14 ft, the AMDR will be less sensitive than the 22 ft variant that was planned for CG(X) but more sensitive than the SPY-1D air-search/fire-control radar that equips Flight IIA ships.

The power-hungry AMDR will require a costly new electrical system encompassing a more robust electrical grid, and must be able to integrate follow-on systems, adding risk and uncertainty to the Flight III design.

In particular, ship designers will probably have to upgrade the 440 V grid in the current Arleigh Burkes to a 4,160 V grid to accommodate the 10 MW needed to drive the AMDR. Increasing the voltage in a Flight III grid would allow more power to flow safely and reliably to the ship’s systems, but it would incur additional engineering and design expenditures.

Other wrinkles: General Dynamics’ Bath Iron Works shipyard has experience with the 4,160 volt power systems, LaGrone writes, because that’s what’s aboard DDG 1000. But Huntington Ingalls Industries’ yard in Pascagoula, Miss., has only delivered 440 volts, so that learning curve, along with “non-recurring engineering costs,”  could increase the price tag for the ships.

Plus, although the story does not mention this, the Navy has said it would like future copies of its DDG 51s to sail with a “hybrid” main propulsion system, perhaps similar to the one we just heard about aboard the USS Makin Island. Future destroyers might use their main and auxiliary gas turbines to generate electricity the ship could direct either to new weapons and sensors, or to push itself through the water. That upgrade, and others, could also drive up the cost.

The silver lining, LaGrone writes, is that most ship classes decrease in cost after the first few copies. That has certainly been true for the DDG 51s, which today roll out of the yards about as painlessly as a naval ship could. That was the whole point, in fact — why not just stick with a design the yards already know well and bolt on a few improvements?

Well — that’s what happened. Even though these projections make it sound as though the Flight III could cost almost twice as much as its predecessor, that may still be a comparative bargain, LaGrone reports:

The navy commenced its Hull and Radar Study in early 2009, when an analysis of alternatives for the CG(X) cruiser called for a 25,000-ton ship that would have cost an estimated – and unaffordable – USD6 billion per hull. CG(X) was cancelled in 2010.

After the almost year-long study, the USN determined that modifying the new Zumwalt-class destroyer – three of which are on order – for the BMD role would not be as cost-effective as a follow-on to the Arleigh Burkes, according to a report published in September by the Congressional Research Service. Elements within the navy’s surface warfare community were resistant to using the Zumwalt’s wave- piercing tumblehome hullform as the basis of the new BMD combatant. The innovative hullform is thought by many to be at its weight limit and have little space for larger radars or future weapon systems such as solid state lasers and electromagnetic rail guns.

That could mean that even at the premiums above the cost of today’s version of the ship, upgraded copies of the Arleigh Burke will remain the Navy’s bread and butter for decades.