An unlikely sparring partner for the U.S. Navy
The U.S. Navy-with the world's largest and most powerful operational fleet-has acquired a small Swedish submarine to help it learn how to fight similar craft in coastal or littoral waters. Playing the aggressor role, the Swedish sub Gotland has demonstrated that antisubmarine warfare (ASW) against non-nuclear submarines is extremely difficult. The Navy today has no non-nuclear subs except the research boat USS Dolphin (AGSS-555). See story pages 24-25.
Gotland is an air-independent propulsion (AIP) submarine, meaning that she can operate for two weeks or more without using her diesel engines, which provide the "signatures" usually used to detect non-nuclear submarines. Gotland is the harbinger of the difficult-to-locate submarines that U.S. naval forces can increasingly expect to find being operated by potentially hostile navies.
In response to this threat, in April 2004 then-Chief of Naval Operations Admiral Vern Clark established the Fleet ASW Command in San Diego and in early 2005 directed the leasing of a modern Swedish submarine to help train the Navy's ASW forces. This led to Gotland arriving at San Diego aboard the Norwegian heavy-lift ship Eide Transporter last June on a one-year lease. The cost of the lease is $17.5 million.
The diminutive Gotland is like no other submarine seen by most U.S. naval officers. Completed in 1996, she has two Stirling, 75-kilowatt external combustion engines that can propel the craft with an electric motor and/or charge her batteries without the need to operate noisy diesel engines. The U.S. ASW forces "have had a very difficult time finding us," said Lieutenant Commander Jan Westas, captain of Gotland's Blue Crew.
Most American visitors to Gotland have found that the boat greatly differs from other submarines with which they are familiar. For her service with the U.S. Navy, Gotland has Blue and Gold crews. Each crew consists of some 35 men and women. When the author was on board in January, Gotland's Blue Crew consisted of 20 officers (three female) and 15 enlisted personnel (one female). The ratio, Commander Westas explained, is caused by the enlisted crewmen being conscripts, in military service for 1½ years. They spend up to six months in training and nine months to one year in the boat. Thus, virtually all specialists and technical personnel are officers. There are no petty officers or chiefs in the American context.
Although quarters are cramped, as in most submarines, Gotland's crew takes special pride in the quality and quantity of food served on board. Obtaining Swedish food for holidays and special occasions is no problem, thanks to a nearby Ikea store and the ingenuity of the cook. In general, the cook prepares American food. No alcohol is served aboard Swedish submarines. And, said Commander Westas, the crews have easily adapted to San Diego's multitude of restaurants, with Italian and Mexican leading the list of favorite cuisines.
The crews alternate at four-week intervals, flying commercially between Sweden and San Diego. Although flying is time consuming and causes jet lag, the system has been highly successful. Some families have made visits to San Diego to vacation with crew members staying over during their off periods. There is also a small liaison group based at San Diego, led by Lieutenant Commander Peter Ostbring, who previously commanded a similar submarine, that handles liaison with the U.S. Navy as well as logistics and maintenance issues.
When the boat goes to sea, two U.S. Navy radiomen are embarked for communications with U.S. forces. At times American officers are aboard for familiarization cruises.
The submarine has two deck levels, with the upper level containing the command and control spaces, a galley with two six-person booths that serve as the mess deck, berthing spaces, and engine rooms. The "hot bunk" situation in Gotland is even more radical than in U.S. submarines: Berthing consists of two- and four-person rooms, except that the captain has his own cubicle. Other than the captain, chief engineer, and (enlisted) cook, all of the crew hot bunks! The submarine normally has only 15 permanent bunks, but because Gotland carries no torpedoes while in U.S. waters, additional bunks have been set up in the torpedo room.
Forward on the lower level is the torpedo room with four 21-inch and two 15.75-inch tubes. The latter can each accommodate two "short" ASW torpedoes for self-defense. A total of 12 long and 6 short torpedoes are normally embarked.
The lower level also contains the batteries, auxiliary machinery, storage space, and the, large refrigerated tanks that keep the liquid oxygen (LOX) at minus 297º. There have been no problems with the volatile LOX, but Commander Westas stresses that it must be handled by specially trained personnel. Swedish submarines have used this form of AIP since 1988.
Gotland also has a conventional diesel-electric plant with snorkel. The twin diesels, however, are normally employed only to enter and leave port. Submerged she normally operates on her two quiet Stirling engines, which can drive her at about ten knots while keeping a fully charged battery available. Her electric motor can use both the Stirling engines and battery power to drive her at some 20 knots submerged. Gotland's Stirling engines use kerosene for fuel, with LOX as the oxidizer for two-week-plus "silent" patrols. The Stirling engines and LOX stowage have added slightly more than 39 feet to the submarine's length.
With her alternating crews, Gotland has played undersea opponent for U.S. carrier strike groups, maritime patrol aircraft, and attack submarines, as well as serving as a neutral and friendly sub in exercises. Her success is attested to by ongoing Navy-to-Navy discussions to renew the lease for another year, until June 2007. While the U.S. Navy refers to the Gotland project as a "lease," the Swedish Navy, said Commander Ostbring, "looks upon it as a bilateral cooperation during which the U.S. Navy will reimburse Sweden for all the extra expenses that follow when you are operating a long way from home."
Some problems have been encountered by Gotland. Commander Westas notes that for the first six months the submarine was forced to use high-frequency (HF) radio to communicate with American forces, a means largely abandoned by the U.S. Navy. Satellite communications gear has now been installed in the boat. And, obtaining spare parts from Sweden takes shipping time, with further delays encountered because of U.S. customs regulations against importing military equipment.
Gotland will spend some 160 training days at sea during her first year with the U.S. Navy, normally deploying for 12 to 16 days to help U.S. ASW forces learn how to cope with small, quiet submarines. It has been difficult for the Americans even though the exercises have been carried out in deep water. Proposed exercises with Gotland in coastal waters will undoubtedly prove much more difficult. "At what we do," said Commander Westas, "we are the best-IRS [intelligence, reconnaissance, surveillance], special ops close to the shore for long periods of time . . . ."
Table 1. Gotland Characteristics
Builders Kockum AB, Mälmo
Displacement 1,526 tons standard
1,647 tons submerged
Length 198 1/6 feet overall
Beam 20 1/4 feet
Draft 18 1/3 feet
Propulsion 2 diesel engines
(1,300 brake horsepower each)
2 Stirling engines
(75 kilowatts each)
1 electric motor
(1,800 shaft horsepower)
1 shaft
Speed 10 knots surface
20 knots submerged
Operating 500 feet
depth
Endurance 14 days-plus submerged endurance (without snorkeling)
Personnel 35 (20 officers + 15 enlisted)
Torpedo tubes 4 21-inch (12 torpedoes)