by DAVID AXE
With rising costs and shrinking budgets, many of the world’s navies are finding it difficult to sustain their submarine fleets. Only through concerted effort, and with major innovation, has the U.S. Navy been able to minimize the decline of its own undersea force, still the world’s most powerful.
Submarines — particularly nuclear-powered models — are among the most complex and expensive of modern weapon systems.
The declines in sub fleets vary in severity. The Royal Navy has cut its submarines from 23 in 1990 to just 11 today. The Russian Navy possessed more than 200 nuclear submarines 20 years ago, but is headed towards a long-term fleet of just a dozen each nuclear attack submarines, nuclear ballistic-missile submarines and diesel-powered attack boats.
Even the Chinese navy, growing so rapidly in other regards, is struggling to maintain its submarines. In the 1990s, the People’s Liberation Army Navy began scrapping scores of Soviet-designed diesel submarines in favor of home-built nuclear models plus a dozen Russian-made Kilo-class diesel boats. In 2000, the PLAN operated an estimated 68 submarines. Projections by U.S. analysts in 2006 and 2007 anticipated a PLAN sub force stabilizing at around 75 vessels by 2010. But in early 2011, Beijing possessed slightly more than 60 submarines of all types, according to the U.S. Defense Department’s annual report on Chinese military capabilities.
Just two major navies have plans to expand their submarines forces: Australia and Japan. Australia aims to double its diesel boat fleet to a dozen vessels, but critics have questioned the plan’s feasibility. Japan’s scheme to add six boats to its 16-strong diesel subs is more realistic, as it mostly entails Tokyo slowing the traditional retirement rate for submarines.
The U.S. Navy has shed around 40 nuclear attack submarines since the end of the Cold War. Today the Navy operates 71 submarines — 53 attack boats, four guided-missile boats and 14 ballistic-missile boats. The only submarine in production in the U.S. today, and the backbone of the future undersea fleet, is the Virginia-class attack boat, introduced in 2004. The 2011 edition of the Navy’s 30-year shipbuilding plan anticipates the sub force hovering between 60 and 70 for the next 15 years.
That’s possible only because, starting this year, the Navy doubled annual production of Virginias from one to two. And that depended on reducing the cost of each Virginia to around $2 billion (in 2005 dollars). The Navy even had a slogan for the cost-reduction effort: “2 for 4 in ’12,” meaning two subs for $4 billion total starting in Fiscal Year 2012.
Two major technical innovations underpinned the surge in Virginia production, according to John Holmander, a vice president at Electric Boat in Connecticut, one of two American shipyards building submarines. “We had a situation where we needed to reduce the cost of platform by over $400 million,” Holmander said. It was 2005.
Electric Boat’s design team, in conjunction with the Navy, determined the Virginia‘s 12 Vertical-Launch System tubes, used to launch Tomahawk cruise missiles, were unnecessarily expensive. “The idea was born that if we go from 12 VLS tubes in the forward end of ship down to two, we could reduce a lot of support equipment,” Holmander said. Each of the so-called “large-diameter tubes,” based on similar tubes aboard the Navy’s guided-missile subs, would carry six Tomahawks, preserving the Virginia‘s firepower.
But installing the large tubes meant moving elements of the vessel’s sonar system, in order to make space. There, Electric Boat identified another opportunity for savings. “We took the traditional sonar sphere, which is a pressure vessel with this water-plate boundary that carries all the sonar equipment, and we went and figured out a way to do that with a non-subsafe [i.e., less waterproof] plate design,” Holmander said. “By doing that we were able to reconfigure the bow and put in the two large-diameter tubes in the centerline of the ship.”
“Those two design changes coupled with other changes we had in the bow of the ship reduced the cost of the ship by $40 million dollars.” Other savings would be found. But with the new, cheaper tubes and sonar, Electric Boat was on its way to helping the Navy afford more Virginias, thus saving the American submarine force from the kind of steep decline afflicting other navies.