Feb 17, 2015

Walrus SSK

Bruinvis (S810), one of four Walrus class SSKs.

Walrus (S802). Note the cruciform stern planes.

The initial contract for the first two boats was awarded in 1979 with a second pair ordered in 1985. Construction was delayed by design changes including a lengthening of the hull to accommodate larger diesel generators and also by a serious fire aboard Walrus while it was being fitted out. Consequently the first to commission was Zeeleeuw in 1990, followed by the repaired Walrus in 1992. The second pair, Dolfljn and Bruin vis, were laid down in 1986 and 1988, and completed in 1993 and 1994 respectively.

The basic design of these boats was based on the Zwaardvis class, which has now been retired. The hull dimensions were similar but normal diving depth was increased from 650ft (200m) to 1,000ft (300m) by the use of stronger HT steel. A total of 20 Harpoon missiles or torpedoes can be stowed. The latter may include Mk.48 Mod.4 heavyweight wire-guided torpedoes with a range of 23.5 miles (38km) at 55kt or 31 miles (50km) at 40kt, or Honeywell NT37D wire-guided ASW torpedoes with a range of 12.5 miles (20km). As an alternative, up to 40 mines may be carried instead of the torpedoes and missiles. Designed for ocean operations, the Walrus class boats have an endurance of 60 days at sea.

SPECIFICATION Type: SSK Class: Walrus Displacement: 2,465 tons surface, 2,800 tons dived Length: 223ft (167.7m) Beam: 27.6ft (18.4m) Draught: 23ft (7m) Machinery: diesel electric; 3 SEMT-Pielstick 12 PM 200VG diesels, 6,300hp; 3 alternators, 288MW; 1 Holec motor, 6,910hp; 1shaft Speed & Range: 20kt dived; 10,000 miles (16,100km) (13kt at surface) Complement: 52 Missiles: Boeing Sub Harpoon long-range SSM (launched from torpedo tubes) ASW & USW: 4 21 in (533mm) torpedo tubes, Mk48 long-range wire-guided and NT370 wire-guided medium-range torpedoes Sensors: radar: ZW07 surface search; sonar: TSM 2272 hull-mounted active/passive search and attack; Type 2026 passive towed array; OUUX 5 passive ranging and intercept.