Diesel-electric attack submarine
S-802 class (lead ship)
1974 - 1978
Rotterdamse Droogdok Maatschappij (RDM)
1979 - 1994
Netherlands - RDM
A total of 4 built, production complete.
- UNIT COST
470 million guilders in 1986
Good intelligence systems
Good diving depth
Blue water capabilities
Expensive in maintainance
No AIP systems fitted
The Walrus class is a diesel-electric attack submarine of Dutch origin. It was developed in the 1970s as a replacement for the earlier Zwaardvis class. At the time of development the Walrus class was a very modern submarine and various improvement programs have kept the design up to date.
The Walrus class is a much improved version of the earlier Zwaardvis class. It retains the same teardrop shaped hull, but features numerous internal and external improvements. The use of stronger steel increases diving depth from 220 to 300 meters, automated systems reduce the required crew and X-shaped control planes are fitted. During upgrades a snort exhaust diffuser was added to the rear of the conning tower.
The Walrus class has four 533mm torpedo tubes instead of six in the earlier Zwaardvis class. The Walrus is armed with the Mk 48 torpedo, but can also use the older NT-37 torpedo as used by earlier Dutch submarines. The Mk 48 torpedoes have been upgraded to ADCAP and CBASS standards. The Sub Harpoon can also be launched from the torpedo tubes and all related fire control systems were fitted, however the Sub Harpoon was not acquired by the Netherlands.
The Walrus class is fitted with a bow mounted Octopus passive/active sonar, a Type 2026 towed array passive sonar and DUUX 5 passive sonar. A ZW07 surface search radar is also fitted, as are various ESM and signals intelligence systems. All sensors are connected to the SEWACO VIII combat data system.
A diesel-electric propulsion system powers the Walrus class. It consists of two diesel engines that charge the batteries and provide propulsion under normal circumstances. When submerged below snorting depth an electrical motor is used. The maximum speed is 12 knots when surfaced and 20 knots submerged. The range is 10.000 nm at 9 knots. The maximum diving depth is 300 m.
A total of four ships were built for the Dutch navy and all four remain in service. A mid life update carried out from 2008 to 2011 is to keep the Walrus class serviceable until the year 2025.
The Walrus class is a diesel-electric attack submarine developed in the 1970s. Due to continuous upgrades the Walrus class remains one of the more capable modern non-nuclear submarines in service.
|Crew||52 incl 7 officers|
|Displacement||2.465 t surfaced, 2.800 submerged|
|Machinery||3x SEMT-Pielstick 12 PA4 200 VG diesel engines, 6.300 hp|
1x Holec motor, 6.910 hp
|Speed||12 kt, 20 kt submerged|
|Range||10.000 nm at 9 kt|
|Sensors||Surface search: ZW07|
Sonar: TSM 2272 Eledone Octopus hull mounted, Type 2026 towed arrady, DUUX 5 passive sonar
|Systems||FCS: GTHW integrated torpedo and Harpoon|
Data: SEWACO VIII
|Remarks||300 m diving depth|
|Weapons||TORP: 4x 533mm|
|Weapon1||4x 533mm torpedo tube in front hull|
20 Mk.48/NT-37/Sub Harpoon or 40 mines