RETURN

By Robert A. Hamilton

Day Staff Writer

Among the many high-tech features on the Navy’s next generation Virginia-class submarine is something called the Advanced Swimmer Delivery Vehicle, a sort of mini-submarine atop the hull that will offer Navy commandos a “piggyback” ride to shore.

While that mini-sub is dwarfed by the tremendous size of the Virginia boat, it will still be larger than the Navy’s first full-size submarine, the Holland. At 53 feet 9 inches, the Holland could easily hide behind the 65-foot delivery vehicle.

And weighing only 148,000 pounds, the Holland displaced less than 1-100th of the Virginia’s planned 7,800 tons; with a little maneuvering the Holland could probably hide behind the stern planes of the 377-foot Virginia.

The last century has seen significant technological changes. Automobiles, for instance, are now controlled as much by computers as by human drivers. But an 1899 Oldsmobile still used an internal combustion engine operating on the same principles as its modern counterpart and still ran around on four tires.

The propulsion system of the Holland, on the other hand, was a 45-horsepower gasoline engine for the surface, and a 60-cell battery well that generated 1,500 ampere-hours, which gave it a range of 1,000 miles on the surface and 30 miles submerged.

The Virginia, to be delivered about 2004 with Electric Boat as the designer and lead construction yard, will have a nuclear reactor that won’t be refueled during the life of the boat, and its range will be limited only by its human operators - since there isn’t enough room for a garden, the submarine has to stop every 60 days or so to pick up food.

Other key differences between the two classes of submarine:

• Torpedoes. Holland could be loaded with three Whitehead torpedoes that could be fired from a single tube in the bow. These 11-foot-long, 18-inch-diameter weapons could deliver 110 pounds of explosive guncotton to a range of 1,000 yards. Virginia will carry up to 26 Mark-48 heavyweight torpedoes, which can carry 650 pounds of high explosive more than five miles. But it will also be able to deliver mines and missiles through its torpedo tubes.
 
• Missiles. Holland’s pneumatic dynamite gun would blast a 222-pound projectile to just over a half-mile; aiming was accomplished by raising or lowering the bow. Virginia will have 12 vertical launch tubes for Tomahawk cruise missiles, 3,500-pound projectiles that can deliver 1,000 pounds of high explosive to within inches of a target 1,500 miles away.
 
• Crew size. The Holland carried a crew of six, including a commander, assistant commander, electrician, engineer, gunner and machinist. Although the Navy is still considering automated systems and other features that will adjust the final size of the Virginia crew, it will likely be about 113.
 
• Diving. The Holland could dive to a maximum safe depth of 100 feet. The Virginia’s unclassified depth is “in excess of 800 feet,” and reference works expect it will be able to get below 1,000 feet.

The deeper a submarine can go, the more likely it is going to be able to elude hunters.

The Virginia will also have capabilities that were not even considered in Holland’s time, such as five different types of sonar arrays (wide aperture arrays on the hull, high-frequency chin and sail arrays, a spherical array in the bow, and two different types of towed arrays), as well as countermeasures (one internal reloadable two-barrel launcher, and 14 external launchers).

Designed on computer

Virginia is also going to be the first submarine completely designed on computer, and at the time the construction contract was awarded it was further along in the design process than any previous class of submarine.

Because of the new design-build program inaugurated for the Virginia, it is also expected to encounter fewer problems during construction and operation - the designers worked side-by-side with builders, fleet operators, and even decommissioning crews to make sure the Virginia is designed for a minimum number of problems throughout its life.