Hameenmaa Class, Finland
The Hämeenmaa Class minelayers were built by Finyards (now STX Finland Cruise Oy) at its Rauma shipyard for the Finnish Navy. Two minelayers are currently homeported at Pansio. Primarily designed for laying mines in the Baltic Sea, the Hämeenmaa Class minelayers can also be deployed in escort, patrol, anti-submarine and sea transport missions.
The keel for the lead ship in the class, FNS Hämeenmaa (02), was laid down in April 1991. Hämeenmaa was launched in November 2001 and commissioned in April 1992. The second and final vessel, FNS Uusimaa (05), was laid down in November 1991. It was launched in June 1992 and commissioned in December 1992.
Hämeenmaa Class design and modernisation
The hull of the vessel is made of steel, while alloys have been used in the superstructure. The design incorporates stealth technology. The Hämeenmaa was the first vessel class in the Finnish Navy to possess stealth features. These vessels are classified under ICE-1A and are suitable for round-the-year operations.
The minelayer has a length of 77m, a beam of 11.6m and a draft of 3m. Displacement of the ship is 1,450t. The minelayer can accommodate a crew of 60.
The Hämeenmaa and the Uusimaa underwent a major upgrade at Aker Yards, a Rauma shipyard, during 2006-07. The weapon, fire control, radar and sonar systems onboard have been modernised. The existing missile system has been replaced with the Umkhonto missile system and new decoy systems were installed. Some of the weapon systems were acquired from the decommissioned Tuuli Class combat hovercraft.
The minelayers have been fitted with a new CEROS 200 fire control system (FCS), advanced sensor systems such as the TRS3D-16ES surveillance radar and Kongsberg ST2400 variable depth sonar (VDS), as well as the SS2030 hull mounted sonar. Hämeenmaa was delivered to the navy in April 2007, while Uusimaa was delivered in October 2007. The modernised minelayers conduct European Security and Defence Policy operations.
Command and control
The minelayers are equipped with an EADS command and control system. The system integrates an advanced naval combat system (ANCS), a TRS-3D multimode radar and an MSSR2000 identification friend or foe (IFF) system.
The Hämeenmaa Class is armed with an eight-cell Umkhonto-IR SAM vertical launch system. This vertical launcher can fire eight surface-to-air missiles. The Umkhonto-IR missile has an operational range of 12km and uses an all-aspect infrared, command update "fire and forget" guidance system.
Bofors 57mm equipped
The main gun, fitted to the front, is a Bofors 57mm dual-purpose gun. The Bofors gun can fire at a rate of about 220 rounds a minute with an effective range of 8,500m. Two 12.7mm machine guns and two Heckler & Koch GMG grenade machine guns are also fitted on the vessel.
The minelayer is equipped with two RBU-1200 ASROC (anti-submarine rocket) launchers for attacking the submarines. It has two rails to carry depth charges.
The Hämeenmaa Class vessels have four mine rails off the stern of the ship. The rails can carry 100 to 150 mines. The total length of the four rails is 200m.
In December 2006, the Finnish Navy signed a contract with Rheinmetall Waffe Munition for two MASS decoy systems to equip the two minelayers.
This multi-ammunition softkill system, is a naval self-defence system that provides self-defence from advanced, sensor-guided missiles. The two-launcher configuration system deceives the incoming anti-ship missiles by launching decoys.
The ESM (electronic support measures) equipment includes a Thales DR3000 SIEWS (shipborne integrated electronic warfare system).
Radar surveillance and sonar
The minelayer is fitted with a Sagem electro optical multisensor system, EADS TRS3D-16ES surveillance radar and Furuno navigation radars. The sonar systems include a Simrad hull-mounted sonar and a Kongsberg VDS.
The Hämeenmaa Class minelayers are powered by two Wärtsilä Vasa 16V22 diesel engines, driving two controllable pitch propellers. The engine delivers a power output of 2,600kW. A bow thruster is also fitted for better manoeuvrability. The propulsion system provides a maximum speed of 20kt.