Västergötland-class Patrol Submarine

The Västergötland-class Patrol Submarines are a class of four submarines in service in the Swedish and Singaporean navies.

The original four ships of the class (Västergötland, Hälsingland, Södermanland, and Östergötland) were built between 1983 and 1988 by Kockums AB. The latter two have undergone comprehensive refits, including the insertion of a new hull section with an air-independent propulsion system equipped with Stirling engines. They have been recommissioned in 2003-2004 as the new Södermanland-class.

Västergötland and Hälsingland were put in reserve until November 2005, when they were sold to the Republic of Singapore Navy as the Archer-class. They were refitted to Södermanland-class standards and received additional climatisation for use in tropical waters, and relaunched in 2009-2010.

Original Specifications

 * Type: Diesel-Electric Patrol Submarine
 * Service Period: 1987-Present
 * Characteristics
 * Length: 159 feet 1 inch (48.49 meters)
 * Beam: 20 feet (6.1 meters)
 * Draft: 18 feet 4 inches (5.59 meters
 * Displacement: 1,070 tons (Surfaced); 1,150 tons (Submerged)
 * Crew: 24
 * Propulsion: 2 x Hedmora V12A/15, 1 x Jeumont-Schneider electric motor
 * Speed: Surfaced - 11 knots (20.37 km/hr); Submerged - 20 knots (37.4 km/hr)
 * Sensor Suite:
 * CSU 90-2 Integrated sonar sensor suite
 * Armament
 * 6 x 533mm torpedo tubes
 * 3 x 400mm torpedo tubes

Refit Specifications

 * Type: AIP-equipped Diesel-Electric Submarine
 * Service Period: 2004-Present
 * Characteristics
 * Length: 198 feet 6 inches (60.5 meters)
 * Beam: 20 feet (6.1 meters)
 * Draft: 18 feet 4 inches (5.59 meters)
 * Displacement: 1,400 tons (Surfaced); 1,500 tons (Submerged)
 * Crew: 24
 * Propulsion: 2 x Hedemora diesel-electric engines, 2 x Kockums v4-275R Sterling AIP units
 * Speed: 20 knots (37.04 km/h)
 * Sensor Suite:
 * CSU 90-2 Integrated sonar sensor suite
 * Armament
 * 6 x 533mm torpedo tubes
 * 3 x 400mm torpedo tubes

Archer-class Specifications

 * Type: AIP equipped Diesel-Electric Patrol Submarine
 * Service Period: 2011-Present
 * Characteristics
 * Length: 198 feet 6 inches (60.5 meters)
 * Beam: 20 feet (6.1 meters)
 * Draft: 18 feet 4 inches (5.59 meters)
 * Displacement: 1,400 tons (Surfaced); 1,500 tons (Submerged)
 * Crew: 28
 * Propulsion: 2 x Hedemora diesel-electric engines, 2 x Kockums v4-275R Sterling AIP units
 * Speed: Surfaced - 8 knots (14.82 km/hr); Submerged - 15 knots (27.78 km/hr
 * Sensor Suite: FAS
 * Armament
 * 6 x 533mm torpedo tubes
 * 3 x 400mm torpedo tubes

Unit Run

 * HSwMS Västergötland (S66) - sold to Singapore in November 2005, renamed RSS Swordsman (S06)
 * HSwMS Hälsingland (S67) - sold to Singapore in November 2005, renamed RSS Archer (S05)
 * HSwMS Södermanland (S68)
 * HSwMS Östergötland (S69)