Admiral: Diesel Subs OK for Others, Not U.S.

Military.com

Christopher J. Castelli | April 25, 2006

 

Diesel submarines have near-shore and stealth capabilities that may make them suitable for other countries but they do not meet U.S. requirements to project and sustain forces far beyond coastal waters, according to the Navy's submarine director, Rear Adm. William Hilarides.

 

The Navy has long opposed acquiring diesel subs, arguing nuclear-powered subs are superior. The subject came up again when Hilarides briefed reporters about submarines at the Washington Navy Yard April 17.

 

“If we were defending our coast from high-end ships, then a diesel submarine might make sense for that, but we project our submarines out to the far corners of the world and need them to stay there for long periods of time,” Hilarides said.

 

He said the short-range capabilities of diesel subs may be appropriate for countries that conduct naval operations close to shores. One country that Hilarides cited was Taiwan, which for the last few years has been considering whether to buy eight diesel subs from the United States (see related article).

 

While the service currently has more than 50 nuclear submarines, only one diesel sub remains in the fleet, the Dolphin (AGSS-555). The Dolphin is used exclusively for research purposes. The Navy decided to stop constructing diesel subs in 1956 and decommissioned the last diesel sub used for standard practices in 1990, according to the March 2006 issue of Proceedings.

 

But not everyone agrees the Navy should shun diesel subs. Author and analyst Norman Polmar said the short-range, stealth capabilities of non-nuclear subs would add needed capabilities to the United States.

 

“I would certainly think for special operations . . . especially when you look at the shallow waters around Korea and certain other countries in the Pacific, a few special purpose diesel submarines based in Japan could be very effective,” he told Inside the Navy. Polmar emphasized that non-nuclear subs would also be effective for anti-submarine missions and research and development projects.

 

He touted the effectiveness of non-nuclear subs that operate on air independent propulsion. Polmar said that while nuclear subs may be more effective than their non-nuclear counterparts in many aspects, non-nuclear subs are often less detectable than nuclear vessels. Even the United States has trouble detecting non-nuclear subs, Polmar said. He noted that putting ashore a handful of special operations troops makes more sense with a vessel manned by 35 people than with an 18,000-ton vessel manned by 140 people.

 

“The U.S. cannot detect non-nuclear submarines when they're operating on battery,” he said. “It's very difficult to find them, almost impossible in coastal operations, and that's where we're going to be in the future.”

 

Hilarides acknowledged that diesel subs often have more stealth qualities once they reach their destination, but said getting diesel subs to their place of operation and maintaining them there can be a problem.

 

“A diesel submarine sitting on the bottom is relatively quiet thing, but it has to get there, and it has to be relatively supportive there,” he said.

 

Hilarides and Polmar also had some disconnect on the cost of non-nuclear submarines.

 

The admiral said that diesel subs would cost $1 billion for the hull and for installing modern U.S. equipment on the vessel. While nuclear submarines are projected to cost $2.4 billion, Hilarides suggested that savings for diesel subs would be inadequate.

 

“So it would be two-for-one . . . if you were to buy a submarine like that,” he said. “And it has nowhere near the stealth, endurance, deployability and on-station time that we need for our submarines.”

 

Polmar said that the cost for non-nuclear subs would be even lower. He speculated that cost for the lead-boat would be about a $500 million and then the cost “would go down precipitously.”

 

Inexpensive submarines would be helpful, he said, predicting the Navy would not be able to meet its $2 billion per-submarine cost goal for the nuclear-powered Virginia class subs (see related article).

 

“The cost of SSNs and the cost of training their crews and the added on cost of handling their reactor cores and handling the submarines themselves . . . is just a tremendous cost,” he said.

 

Polmar said the Energy Department picks up the cost for fueling reactor cores, so energy costs are not included in the Defense Department budget, making nuclear sub costs seem smaller than they actually are.

Herman, I have recently been toying around with diesel subs in H4.1 and I must say that their employment in the littorals presents a facinating tactical dilemma for the ASW commander, albeit I only find it facinating since I am not the one looking for the sub.

Cost Cutting the Super Sub

 

The Navy's submarine force is in trouble. A shrinking number of boats is struggling to meet steady demand from regional commanders. Meanwhile, the cost of the only U.S. submarine currently in production, the super-high-tech Virginia-class attack boat, has risen to $2.3 billion apiece. At that price, the Navy can afford to buy only one per year. Do the math: since attack boats last only 30 years, building one boat per year means your fleet is eventually going to shrink to 30 boats from the current 55. Long-range plans call for 48 attack subs, so how is the Navy going to get there?

 

virginia.jpgSome observers have called for the Navy to start production of new, smaller and cheaper boats, perhaps even diesel-electrics rather than nukes. But the long ranges that U.S. boats must travel, their need for big hulls (for mission flexibility) and the strong pro-nuke culture of U.S. submariners means diesels aren't a realistic option.

 

Plus, no U.S. shipyard has built diesel boats in more than 50 years, so where would you get them from? Germany? Sweden? Both countries build fine diesel boats, but Congress ain't likely to go begging to these reluctant allies for cheap submarines. No, nukes are where it's at, and nukes never come cheap. The Navy wants to buy two Virginias per year to sustain fleet numbers, but it refuses to do so unless the price drops to $2 billion. The two U.S. submarine manufacturers -- Newport News and Electric Boat -- want the work, but can they knock $300 million off the Virginia's price?

 

Aviation Week has run a story on efforts to trim Virginia's cost:

 

The most effective way to lower the per-hull price of Virginias, by more than $150 million apiece, is a more efficient build rate to distribute overhead costs and increase learning efficiencies, according to [Deputy Assistant Secretary of the Navy for Ships Allison]Stiller, Vice Adm. Paul Sullivan, head of Naval Sea Systems Command, and Rear Adm. Charles Hamilton II, program executive officer for ships. An additional $25-$80 million in savings is possible through a "reallocation" between the shipbuilders, they said.

 

A second story goes into detail:

 

Seven capital-expenditure (capex) projects have been approved or are in development to help General Dynamics Corp.'s Electric Boat and Northrop Grumman Corp.'s Newport News slice costs off the Virginia-class submarine program, Navy Rear Adm. William Hilarides said April 17. ...

 

Five capex efforts have been approved, including a light fabrication project at Electric Boat's Quonset Point shipyard. There also is a centralized coating facility there, and Electric Boat has a module transportation project underway as well. For its part, Newport News has a modular outfitting facility and has upgraded its horizontal machining center. ...

 

Meanwhile, the boat's bow design will be simplified under new design work already budgeted and should be implemented in the FY '10 sub, Hilarides said. The design will move sonar hydrophones and the vertical launching system, but it will not affect any expected capabilities. ...

 

Nevertheless, Hilarides said the Navy would consider removing the special forces' lock-out chamber on the Virginia boats if capabilities had to be cut. Other options include using passive instead of active sonar and a classic propeller instead of the "propulsor," which provides more stealth, he said.

 

The lock-out chamber in question allows SEALs to exit and enter the sub while it's submerged. If the chamber goes, the subs lose much of their special operations capability -- one of their major selling points. If this happens, the U.S. Navy won't be the first sea service to surrender submarine-based special operations. This year, on cost grounds, the Royal Navy retired its only sub with a lock-out chamber.

 

--David Axe

 

Defense Tech: Ships and Subs Archives