Built in 2014 at STX Rauma Shipyard the coastguard vessel TURVA is 95.9m long and 17.4m wide, making her the largest vessel ever commissioned by the Finnish Border Guard. Fully laden, she draws 5m of water. At design draught, the vessel has a deadweight of 660t while her maximum deadweight is around 1800t. Her complement will be approximately 30.
The main purposes of the new offshore patrol vessel are open sea patrol and ensuring border safety. TURVA carries a rigid-hulled inflatable boat and a larger patrol boat, both stowed in covered recesses, that can be used to carry a vessel inspection teams to intercepted ships. While the vessel does not have a hangar, the forward helipad with folding “wings” is large enough for receiving and refueling a Eurocopter AS332 Super Puma, the largest type of helicopter operated by the Finnish Border Guard, during search-and-rescue operations at sea. TURVA is the first Finnish patrol vessel fitted with such capability. For surveillance, TURVA has a Cassidian TRS-3D radar and extensive command and control systems which allow the ship to direct large rescue operations both in the air and on the surface. The vessel is also fitted with underwater surveillance systems.
TURVA is also equipped for rescue operations, firefighting, emergency towing and demanding environmental duties. She can perform mechanical recovery of spilled oil with built-in recovery systems in open water, either by using conventional outriggers and booms in calm seas or a stiff steel boom and a special wave-dampening channel in heavy weather. The oil recovery system has been manufactured by the Finnish company Mobimar which has also provided equipment for other Finnish patrol vessels. Furthermore, the vessel is also fitted for but not with equipment capable of recovering oil in ice conditions. The internal storage tanks are dimensioned for 1000m3 of recovered oil and 200m3 of recovered chemicals. The 350m2 open aft deck is covered with tropical hardwood, Iroko. For diving support and oil recovery tasks, TURVA carries a smallworkboat.
TURVA is powered by three environmentally friendly Wärtsilä 34DF series dual-fuel engines capable of burning both diesel fuel as well as liquefied natural gas (LNG). For redundancy and safe return to port, the engines are arranged in two independent engine rooms divided by a watertight bulkhead. In the aft engine room, a 12-cylinder Wärtsilä 12V34DF producing 6400kW is mechanically coupled to a controllable pitch propeller. In the forward engine room, two 6L34DF generating sets with an output of 3000kW each produce power for two electrically-driven Azipull AZP120CP thrusters. If the forward engine room is damaged, the shaft generator coupled to the bigger engine can be used to produce electricity for the azimuth thrusters, which are required for steering the vessel as she has no separate rudders, and other onboard systems. Since the azimuth thrusters are powered by electric motors and the centerline shaft is mechanically coupled to the main engine, the propulsion system as a whole could be referred to as “combined diesel-electric and diesel” (CODLAD). TURVA is the first ship fitted with this type of propulsion arrangement – two azimuth thrusters and a centerline shaft – which was originally developed for icebreakers and icegoing LNG carriers. For maneuvering and DP2 classdynamic positioning, the ship has a transverse bow thruster and a retractable azimuth thruster in the bow.
TURVA is the first LNG-powered offshore patrol vessel as well as only the second LNGpowered ship (after VIKING GRACE) to enter service in Finland. Unlike in the ferry, which has two deck-mounted LNG storage tanks, the single fuel tank in TURVA is built inside the vessel.
The service speed of the vessel will be 18 knots and despite her bulbous bow she will also be capable of breaking level ice up to 0.80m in thickness. With a bollard pull of approximately 100t, TURVA is capable of towing even the largest tankers regularly sailing in the Baltic Sea.