Tag: Stealth

Ships in Profile: Hamina-class missile boat

Hamina-class Missile Boat, Finnish Navy.

The Hamina-class missile boat is a class of fast attack craft of the Finnish Navy. They are classified as “missile fast attack craft” or ohjusvene, literally “missile boat” in Finnish.

The vessels were built in the late 1990s, early 2000s, and are the fourth generation of Finnish missile craft. The first vessel was ordered in December 1996 and the fourth was handed over on 19 June 2006. Since the launch of the Helsinki-class missile boats, all fast attack craft have been named after Finnish coastal cities. The class was previously known also as Rauma 2000 following its predecessor the Rauma class.

The four vessels form what the Finnish Navy calls Squadron 2000 (Finnish: Laivue 2000). Initially the Finnish Navy considered several different compositions for the new squadron, and at one point only two Hamina-class vessels and four Tuuli-class ACV were to have been built. After a strategic shift of the Finnish Navy’s role, the composition of the Squadron 2000 followed suit. The Tuuli-class prototype was never fully equipped, nor fitted for operational use and its three sisters were cancelled, instead two more Hamina-class boats have been built; with some of the equipment intended for the Tuulis being used in the Haminas. The fourth and final Hamina-class vessel was delivered in summer 2006.

The squadron reached its full operational capability in 2008 and have greatly improved the surface- and air surveillance as well as air defense capability of the Finnish Navy. Their electronic surveillance suite also increases the quality of information available to military leaders.

All ships were built at Aker Finnyards in Rauma, Finland. The vessels have their home base at Upinniemi.

In March 2014 it was announced that the Hamina-class missile boats will be upgraded in the near future.

The vessel’s hull is constructed of aluminum and the superstructures are constructed of re-enforced carbon fiber composite. The vessels have a very low displacement and are very maneuverable. They are equipped with water jets instead of propellers, which allow them to operate in very shallow waters and accelerate, slow down and turn in unconventional ways.

The Hamina class are very potent vessels, boasting surveillance and firepower capacities which are usually found in ships twice the size.

The Hamina class has been designed and constructed as stealth ships with minimal magnetic, heat and radar signatures.

The shape of the vessel has been designed to reduce radar signature. Metal parts have been covered with radar absorbent material, and the composite parts have radar absorbent material embedded in the structure. Radar transparent materials (kevlar, balsa) have been used where applicable.

Unlike glass fiber, carbon fiber blocks radio waves. This protects ship’s electronics against electromagnetic pulse. In addition, it stops any radio frequency signals generated by ships electronic devices escaping outside. Except for the bridge, the vessel has no windows that would allow the signals to escape.

FNS Pori (83) Finnish Navy Hamina class missile boat – Helsinki South Harbor.

The vessel contains hardly any steel parts, thus generating very low magnetic field. The remaining magnetic field is actively canceled with electromagnets.

Exhaust gases can be directed underwater to minimize thermal signature, or up in the air to minimize sound in submarines direction. 50 nozzles around the decks and upper structures can be used to spray seawater on the vessel to cool it. In addition, the nozzles can be used to clean the ship after chemical attack or radioactive fall-out.

Weapons

The Hamina class have the latest in surveillance and weapons technology all integrated into an intelligent command system. A Hamina class vessel can monitor about 200 kilometres (120 mi) of air space and its Umkhonto surface-to-air missile system can simultaneously engage a maximum of eight aircraft, up to 14 kilometres (8.7 mi) away, while the vessel’s anti-ship missiles have a range in excess of over 250 kilometres (160 mi).

Hamina Class Missile Boat Umkhonto surface-to-air missile system.

The Hamina class’ primary weaponry is four RBS-15 Mk.2 anti-ship missiles. The vessels are further equipped with a Bofors 57 mm gun against surface and aerial targets as well as the Umkhonto-IR surface-to-air missiles, MASS decoy system and two 12.7 mm heavy machine guns. It is also possible to use the ships for mine-laying.

Hamina-class Bofors 57mm Gun.

The software of the centralized combat control system is COTS oriented, built on top of Linux running on redundant x86 rack servers, which makes maintenance and future updates and optimizations simpler.

Vessels

FNS Hamina
Pennant number: 80
Builder: Aker Finnyards
Ordered: December 1996
Commissioned: 24 August 1998
Home base: Upinniemi
Current status: In active service.
FNS Tornio

 Tornio (81)
Pennant number: 81
Builder: Aker Finnyards
Ordered: 15 February 2001
Commissioned: 12 May 2003
Home base: Upinniemi
Current status: In active service
FNS Hanko
Pennant number: 82
Builder: Aker Finnyards
Ordered: 3 December 2003
Commissioned: 22 June 2005
Home base: Upinniemi
Current status: In active service

 Pori (83)
FNS Pori
Pennant number: 83
Builder: Aker Finnyards
Ordered: 15 February 2005
Commissioned: 19 June 2006
Home base: Upinniemi
Current status: In active service.
Class overview
Name: Hamina
Operators:  Finnish Navy
Preceded by: Rauma class
Succeeded by:
Completed: 4
Active: 4
General characteristics
Type: Fast attack craft
Displacement: 250 tons
Length: 51 m (167 ft)
Beam: 8.5 m (28 ft)
Draught: 1.7 m (5 ft 7 in)
Propulsion:
  • 2 × MTU 16V 538 TB93 diesels; 5520 kW.
  • 2 × Rolls Royce Kamewa 90SII waterjets
Speed: over 30 knots (56 km/h; 35 mph)
Range: 500 nmi (930 km; 580 mi)
Complement: 26
Sensors and
processing systems:
  • Saab Ceros 200 with 9LV FCS (Saab)
  • Consilium Selesmar maritime radar
  • TRS-3D/16-ES multimode acquisition 3D radar (EADS)
  • ANCS 2000 Combat Management System (EADS)
  • MSSR 2000 I IFF (EADS)
  • EOMS (SAGEM)
  • Simrad Subsea Toadfish sonar
  • Sonac/PTA towed array sonar (Finnyards)
Electronic warfare
& decoys:
  • MASS (Multi Ammunition Soft-kill System) (Rheinmetall)
  • Decoys: Philax chaff, IR flares
  • Smoke system: Lacroix ATOS
  • EMS: Matilda radar warning system (Thales)
Armament:
  • 1 × Bofors 57 mm/70 SAK Mk3
  • 2 × 12.7 mm machine guns (NSV)
  • 8 × Umkhonto-IR SAM (Denel)
  • 4 × RBS-15 Mk2 SSM (Saab)
  • 1 × rail for depth charges or mines (Sea Mine 2000)

Ships in Profile: Visby-class corvette

HSwMS Helsingborg (K32)

The Visby class is the latest class of corvette to be adopted by the Swedish Navy after the Göteborg and Stockholm-class corvettes. The ship’s design heavily emphasizes low visibility, radar cross-section and infrared signature. 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.

The hull is constructed with a sandwich design consisting of a PVC core with a carbon fibre and vinyl laminate[4] (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.

Visbys 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.

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 adaptation. 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, on 18 September 2008 the Genomförandegruppen cancelled the project in order to rationalize the procurement of defence materiel for the Swedish defence.

HSwMS Helsingborg (K32), Stockholm.

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 Active
HMS Visby vapen, korvett.svg
K32 Helsingborg 27 June 2003 16 December 2009 3rd Naval Warfare Flotilla Active
HMS Helsingborg vapen.svg
K33 Härnösand 16 December 2004 16 December 2009 3rd Naval Warfare Flotilla Active
HMS Härnösand vapen.svg
K34 Nyköping 18 August 2005 16 September 2015 3rd Naval Warfare Flotilla Active
HMS Nyköping vapen.svg
K35 Karlstad 24 August 2006 16 September 2015 3rd Naval Warfare Flotilla Active
HMS Karlstad vapen.svg
K36 Uddevalla Cancelled
HMS Uddevalla vapen.svg

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.

Class overview
Name: Visby class
Builders: Kockums
Operators:  Swedish Navy
Preceded by: Göteborg class
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:
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:
Electronic warfare
& decoys:
Rheinmetall TKWA/MASS (Multi Ammunition Softkill System)
Armament:
Aviation facilities: Helicopter pad