The Wrong Sub for New Warfare Era
With the paradigm shift from strategic to tactical warfare operations, the United States Navy has found itself with an aging fleet of virtually obsolete nuclear submarines designed to fight a war that never happened – and which they played a significant role in preventing. (For a review of the post-Cold War state of our nuclear submarine fleet and the modern alternatives waiting in the wings to supplement or even replace these aging behemoths, see my 2002 article, “Tomorrow’s Submarine Fleet – The Non-nuclear Option,” DefenseWatch, Feb. 6, 2002).
In the two and a half years since that article appeared, the world of submarine warfare has changed significantly. This month, on Sept. 3, the nuclear submarine that eventually will be commissioned as the USS Virginia (SSN 774) underwent sea trials off the coast of New England.
According to Adm. Frank Bowman, director of naval nuclear propulsion, “This sea trial was an absolute success, a clean sweep, as we say in the Navy. It met every expectation of mine, for the propulsion plant and for the ship.”
It was, as the Navy says, a “clean sweep.”
The Virginia is the result of several years of round-the-clock efforts by thousands of people from 3,500 companies located in 46 states. It is an extraordinarily stealthy, futuristically high-tech, astonishingly expensive underwater marvel. To the tune of $2 billion.
What did we get for our hard-earned bucks?
The sub is 377 feet long with a beam of 34 feet, and it displaces 7,300 tons submerged. Compare this to the other “new” submarine – the USS Seawolf (SSN 21) – 353 feet long, 40 feet beam, displacing 9,137 tons submerged.
The Virginia carries a plethora of systems and weapons designed to keep the sub quiet, and to allow it to operate near-shore for battlefield support and for unmanned vehicle and Seal Team deployments.
A major element in the argument for canceling all but three of the proposed twenty-nine Seawolf Class subs was the substantial per-sub cost of about $2 billion. The new Virginia Class was supposed to cost less, but at you can see, it didn’t work out that way. Furthermore, the smaller Virginia Class was supposed to be better suited for operating close inshore, but – again as you can see – these subs are 24 feet longer. Because they displace significantly less, they are more maneuverable, but their added length limits their maximum angle when operating in waters about as deep as they are long.
In my earlier article discussing the non-nuclear submarine option, I pointed out that a typical modern Air Independent Propulsion (AIP) submarine costs about $250 million. As I related in that article, AIP design since the end of World War II has followed on four different fronts:
* German Thyssen Nordseewerke (TNSW) developed a closed-cycle diesel using liquid oxygen, diesel oil, and argon. The same diesel is used as a conventional air-breathing engine for surface propulsion. These systems are suitable for both retrofitting and new construction.
* Howaltswerke-Deutsche Werft (HDW) in Germany has developed a hybrid fuel cell system for a diesel-electric sub. High-speed operations run off the conventional battery, while the fuel cell recharges the battery, and provides energy for low-speed operations. Typical submarine cost using either HDW or TNSW AIP systems is $250 million.
* Hybrid diesel-electric units propel Swedish Gotland Class subs, supplemented with Kockum Stirling engines running on liquid oxygen and diesel oil to turn a generator to produce electricity for propulsion and to charge the vessel’s batteries. Typical cost for a Gotland class sub is $100 million.
* The French “MESMA” (Module d’Energie Sous-Marine Autonome) AIP steam-turbine system burns ethanol and liquid oxygen to make steam to drive a turbo-electric generator. The design permits retrofitting into existing submarines by adding an extra hull section. Typical cost for a new submarine powered by MESMA is $250 million.
In a phone interview early this month with the Newhouse News Service, Capt. Tom Abernethy, who commands the sub-hunting Destroyer Squadron 22 based in Norfolk, Va. , said: “Shallow water, you get a lot of noise reverberation and additional traffic, and you’re fighting in somebody else’s back yard which they know pretty well …. [In that environment, even a diesel sub] is absolutely a real threat, a formidable threat …. ” By implication, he said that AIP subs were equal to or better than anything we have.
Vice Admiral Albert H. Konetzni Jr. of the Navy’s Fleet Forces Command wrote in the June 2004 issue of the U.S. Naval Institute Proceedings: “The uncontested undersea superiority experienced during recent conflicts is not likely to be repeated against determined and capable adversaries.”
Robert G. Williscroft is DefenseWatch Navy Editor