Visby-class corvette

HSwMS Helsingborg (K32)
Class overview
Name	Visby class
Builders	Kockums
Operators	Swedish Navy
Preceded by	Template:Sclass-
Cost	$184 Million
In commission	16 December 2009
Planned	6
Completed	5
Cancelled	1
Active	HSwMS Visby HSwMS Helsingborg HSwMS Härnösand HSwMS Nyköping HSwMS Karlstad
General characteristics
Type	Stealth Missile Corvette
Displacement	640 tonnes
Length	72.7 m (239 ft)
Beam	10.4 m (34 ft)
Draught	2.4 m (7.9 ft)
Propulsion	CODOG 2 × 125SII Kamewa Waterjets 4 × Vericor TF50A gas turbines, total rating 16 MW 2 × MTU Friedrichshafen 16 V 2000 N90 diesel engines, total rating 2.6 MW 3 × generators of 270kW each
Speed	35 knots (65 km/h)+
Range	2,500 nmi (4,600 km) at 15 kn (28 km/h)
Complement	43
Sensors and processing systems	Saab 9LV combat management system Saab Sea_GIRAFFE AMB 3D PESA surveillance radar Saab Ceros 200 stealth fire control radar system Condor CS-3701 tactical radar surveillance system GDC Hull-mounted sonar Hydroscience Technologies towed array sonar system GDC variable depth sonar
Electronic warfare & decoys	Rheinmetall TKWA/MASS (Multi Ammunition Softkill System)
Armament	1 × Bofors 57 mm Mk3 8 × RBS15 Mk2 AShM 4 × 400 mm torpedo launchers for Type 45 torpedoes Mines and depth charges Provision for but not fitted with 2 × 6 127 mm ALECTO anti-submarine rocket launchers (cancelled) 12 × Umkhonto SAM(cancelled)
Aviation facilities	Helicopter pad

The Visby class is the latest class of corvette to be adopted by the Swedish Navy after the Template:Sclass- and Template:Sclass- corvettes. The ship's design heavily emphasizes low visibility or stealth technology. The first ship in the class is named after Visby, the main city on the island of Gotland. The class has received widespread international attention because of its capabilities as a stealth ship.

The ships are designed by Swedish Defence Materiel Administration (FMV) and built by Kockums AB. The first ship of the class was launched in 2000 and since then the construction was fraught with repeated delays. Finally in December 2009, the first two ships of the class were delivered to the Swedish Navy by the FMV, albeit with greatly reduced operational capability.

Design

The hull is constructed with a sandwich design consisting of a PVC core with a carbon fibre and vinyl laminate (see also the Oceanic-Creations spin-off). There are multiple advantages to using composite materials in ship hulls. Good conductivity and surface flatness means a low radar signature, while good heat insulation lowers the infrared signature and increases survivability in case of fire. The composite sandwich used is also non-magnetic, which lowers the magnetic signature. Composites are also very strong for their relative weight, and less weight means a higher top speed and better maneuverability. The composite weighs roughly 50% less than the equivalent strength steel. If built with normal steel the ship would weigh in at around 1200 tonnes.

Visby's angular design reduces its radar signature (or radar cross section). Jan Nilsson, one of the designers, told BBC News Online: "We are able to reduce the radar cross section by 99%. That doesn't mean it's 99% invisible, it means that we have reduced its detection range." The 57 mm cannon barrel can be folded into the turret to reduce its cross section. There are plans for additional improvements in this area, especially for the deck rails and masts.

History

Much of the design was based on the experiences learned from the experimental ship HSwMS Smyge. The class was originally designed to be divided into two subcategories where some ships were optimized for surface combat and others for submarine hunting; however, this was changed due to cutbacks.

A helicopter, such as the Agusta Westland A109M selected by Sweden, can land, take off, and refuel on the upper deck. A helicopter hangar was originally planned but was considered to be too cramped and was removed.

The ships took an exceptionally long time from launch to delivery and the construction has been fraught with repeated delays. In 2008, the only weapons system that had been integrated and tested in Visby was the gun.

Finally, on 16 December 2009, the first two of the corvettes were delivered to the Swedish Navy by the Försvarets materielverk (FMV). The two ships, K32 and K33, were delivered with underwater and surface/air sensors fully integrated. However, the only weapon that had been integrated and test fired on the ships was still the Bofors 57 Mk3 gun. The FMV calls this version 4, which aims to get the ships into service and start training crews.

Version 5 is due in 2012, and is intended to supplement the ships with mine clearance systems, helicopter landing capability (only K31 is certified to date), anti-surface ship missiles and additional stealth adaption. Visby was the first of the corvettes to be upgraded to Version 5. On 22 March 2012 FMV reported that the ship had been modified and that the system would be tested before reentering the Swedish Navy by the end of 2012.

Although the design of the ships originally called for the installation of surface-to-air missiles, in 18 September 2008 the Genomförandegruppen cancelled the project in order to rationalize the procurement of defence materiel for the Swedish defence.

Units

Number	Ship name	Laid down	Launched	Commissioned	Service	Status	Coat of arms
K31	Visby	17 February 1995	8 June 2000	16 September 2015	4th Naval Warfare Flotilla	PTK Visby*
K32	Helsingborg		27 June 2003	16 December 2009	3rd Naval Warfare Flotilla	Active
K33	Härnösand		16 December 2004	16 December 2009	3rd Naval Warfare Flotilla	Active
K34	Nyköping		18 August 2005	16 September 2015	3rd Naval Warfare Flotilla	PTK Visby*
K35	Karlstad		24 August 2006	16 September 2015	3rd Naval Warfare Flotilla	PTK Visby*
K36	Uddevalla	Cancelled

All systems for the ship Uddevalla were acquired, but the ship was later canceled, so there are now plans to build a full Visby class simulator.

PTK Visby is the designation of the formation doing system tests and readying the ships for active service within the Swedish Navy. The formation is under the 3rd Naval Warfare Flotilla but takes its orders from the FMV. The system tests are taking a long time partly because of funding issues and partly because of the novel and cutting-edge nature of the platform.

Similar ships

• Template:Sclass- (United Arab Emirates)
• Template:Sclass- (Finland)
• Type 022 missile boat (China)
• Milgem-class corvette (Turkey)
• Template:Sclass- (Greece)
• Template:Sclass- (Norway)

Gallery

• 
  On a visit to the town Helsingborg.
• 
  Anchored off Gotska Sandön.
• 
  At Karlskrona Naval Base.
• 
  In Stockholm City.

External links

• BBC article
• FMV - Official homepage
• Kockums - Official homepage
• Swedish navy page on the Visby trials Template:Sv
• Naval-Technology - www.naval-technology.com