25 July 2007

Missile Defense and Naval Ships

Britain is justifying a dozen new destroyers (a type of warship) as a ballistic missile defense tool.

U.S. Navy planners are thinking about following suit:

Two cruiser designs are being considered. The first is a new warship based on the controversial DDG 1000 (Zumwalt class) destroyer, which features the controversial “tumblehome” hull. This design is being called an “escort cruiser” to protect aircraft carrier strike groups. It would have gas turbine propulsion, as do all other U.S. cruisers, destroyers, and frigates.

The second cruiser would be a much larger, 25,000-ton, nuclear-propelled ship with a more conventional hull featuring a flared bow. This ship would be optimized for the Ballistic Missile Defense (BMD) mission.

Reportedly, five nuclear-propelled CGN(X) ships and 14 escort cruisers designated CG(X) would be built to fulfill the cruiser requirement in the Navy’s 30-year, 313-ship plan. These ships would be, in part, a replacement for the 22 remaining Ticonderoga (CG 47) missile cruisers, completed between 1986 and 1994. . . the analysis will recommend dropping the Kinetic Energy Interceptor (KEI) from the CG(X) program.

The KEI is a large BMD missile under development by Northrop Grumman as a ground- or sea-based weapon to intercept ballistic missiles in their boost, ascent, and midcourse flight phases.

The KEI is much larger than the SM-3 Standard missile developed by Raytheon to arm Navy cruisers and destroyers for the BMD role. The 40-inch diameter KEI is nearly 39 feet long, while the 21-inch diameter SM-3 stands just over 21 feet tall. . . .

[The] team is said to be firm in its recommendation for the smaller escort cruiser. Details are less developed on the nuclear-powered variant, sources said.

More from the Navy Times:

Under pressure from the Navy to develop a new cruiser based on the DDG 1000 Zumwalt-class hull form, and from Congress to incorporate nuclear power, a group of analysts working on the next big surface combatant may recommend two different ships to form the CG(X) program.

One ship would be a 14,000-ton derivative of the DDG 1000, an “escort cruiser,” to protect aircraft carrier strike groups. The vessel would keep the tumblehome hull of the DDG 1000 and its gas turbine power plant. . . .

Reps. Gene Taylor, D-Miss., and Roscoe Bartlett, R-Md. — the current and former chairman, respectively, of the House Seapower subcommittee — are strong proponents of nuclear power for surface ships, citing concerns about the future supply of oil. Navy officials testified earlier this year that the rising price of oil could soon make the more expensive nuclear option viable, and the House is expected to include language in the 2008 defense bills requiring nuclear power for the new cruisers. . . . the AoA looked at two possible nuclear powerplants based on existing designs: doubling the single-reactor Seawolf SSN 21 submarine plant, and halving two-reactor nuclear carrier plants.

Doubling the 34 megawatts of the Seawolf plant would leave the new ship far short of power requirements — and not even match the 78 megawatts of the Zumwalts.

But halving the 209-megawatt plant of current nuclear carriers would yield a bit more than 100 megawatts, enough juice for power-hungry BMD radars plus an extra measure for the Navy’s desired future directed-energy weapons and railguns.

The anti-missile cruiser also wouldn’t require the high level of stealth provided by the Zumwalt’s tumblehome hull, analysts said, since the ship would be radiating its radars to search for missiles. Returning to a more conventional, flared-bow hull form would free designers from worries about overloading the untried tumblehome hull. . . .

“There’s a concern that the DDG hull has stability problems and doesn’t have growth margin,” said a congressional source. A nuclear-powered option, the source said, also would placate Congress, and “a cash-strapped Navy wouldn’t be fully committed to a nuclear ship.” . . .

[An] analyst, using very rough figures, guessed the cost for a CGN(X) would range from something just under $5 billion to as much as $7 billion.

The Navy estimates its first two DDG 1000s will cost $3.3 billion each, although estimates from the Congressional Budget Office and others put the potential true cost at over $5 billion and as much as $7 billion. . . .a follow-on ship in a class of 25,000-ton nuclear-powered cruisers might cost roughly $4 billion to $5 billion.” . . .

Sources said early analyses of the CGN(X) showed a 25,000-ton ship, which the Navy said was too large. More realistic, one source said, would be about 23,000 tons. . . . The Navy now plans to order the first CG(X) in 2011, with the last ship included in the FY 2023 budget.

My prediction is that the 14,000+ ton escort cruiser concept dies in Congress. It fills a need that the Navy doesn't actually have, because it has a large number of not so old large destroyers that serve precisely the purpose that the Ticonderoga class did, and the DDG-1000 upon which it is based crashed and burned, cancelled after contracts for just two prototype models. Also, what is the point of having nuclear powered aircraft carriers, if the escort ships that it relies upon need conventional fuel?

I personally think that the Navy would be better advised to develop a much smaller, nuclear powered carrier escort (maybe 5000 tons in size, about half the size of existing cruisers and destroyers) with a narrower mission. The smaller carrier escort would not need anti-ship missiles, helicopters, or a strong capability to take on enemy fighter aircraft, all of which would be missions handled by carried aircraft on the aircraft carrier. It also wouldn't need stealth, which is impossible for an aircraft carrier. Instead, it would need to have anti-submarine warfare capability, point defense against anti-ship missiles capability, and anti-small craft capacities, to help defend a carrier group against the kind of swarm attack that military planners have envisioned Iran launching at U.S. carriers facing in the Persian Gulf. As a nuclear powered ship, it could also reduce the logistics trail of the carrier group.

Congress may be more warm to a ballistic missile defense concept because the Navy has far outperformed the Air Force in the success of its missile defense efforts, because nothing in the current fleet is designed for the mission, and because a nuclear powered ship makes sense for a ship designed to spend long tours away from base autonomously.

Enviros in Congress may also favor a new nuclear powered destroyer as proof of concept for nuclear powered surface ships using recent developments in nuclear power technology should this technology be needed in a peak oil era.

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