Voima is a Finnish state-owned icebreaker. Built by Wärtsilä Hietalahti shipyard in Helsinki in 1954, she was the first icebreaker in the world to be equipped with two bow propellersStephen J. Jones: Ships In Ice - A Review . Proceedings of the 25th Symposium on Naval Hydrodynamics.Stephen J. Jones: A history of icebreaking ships. Ocean Sovereignty, Vol. 3, No. 1, 2008. and generated widespread publicity that helped the Finnish shipbuilding industry to become the world leader in icebreaker design.
Voima was extensively refitted in 1978–1979. , she is the oldest and smallest state-owned icebreaker in service in Finland. Originally, Voima was scheduled to be replaced by a new icebreaker by the winter of 2015–16. However, in 2016 it was decided to extend her operational lifetime by at least ten years with another refit.
Development and construction In the Moscow Armistice, signed on 19 September 1944, Finland agreed to pay war reparations of US$300 million to the Soviet Union. The war reparations, paid in the form of ships and machinery over six years, included the newest steam-powered state-owned icebreakers Voima and Jääkarhu. This left Finland with one modern diesel-electric icebreaker, Sisu, which had been damaged by a naval mine during the war, and four older steam-powered icebreakers. Of these, especially Murtaja and Apu were considered nearly obsolete and their efforts in the Archipelago Sea were sometimes described being "mostly of moral nature". As a result, only the ports of Hanko and Turku were kept open through the first post-war winters.Kaukiainen (1992), pp. 226–231.
In 1946, the Finnish Government appointed a committee to start planning the rebuilding of the Finnish icebreaker fleet. The committee, consisting of the director of the Finnish Maritime Administration, Svante Sundman, and two experienced Finnish shipbuilders, K. Albin Johansson and Ossian Tybeck, delivered its final report on the construction of a new icebreaker in the following year. The main dimensions of the new 4,415-ton icebreaker, large enough to escort 10,000-ton dry cargo ships or 16,000-ton tankers, were based on the old Jääkarhu, but the triple-expansion steam engines were replaced with a modern diesel-electric propulsion system, similar to the 1939-built Sisu, with a combined output of 10,500 shp. In the early drafts, the new icebreaker was designed with three propellers (two in the stern and one in the bow) and an asymmetric stem that would compensate for the transverse force caused by the bow propeller.Ramsay (1949), pp. 352–353. However, these features were later dropped after extensive model testing and co-operation with Swedish naval architects in favor of a completely new design.Jäänmurtaja Voima ja sen neljä potkuria. Suomen Laivasto 2/1954, pp. 27–28.
The result was, in many respects, the most advanced icebreaker in the world at the time. Although bow propellers had been a common feature in icebreakers around the world for decades, it was incorrectly believed that they helped with the actual icebreaking process by reducing the pressure under the ice in front of the ship. However, extensive research and recent experiences had shown that bow propellers improved the icebreaking capability because their flushing effect reduced the friction between the broken ice floes and the hull of the ship. The drawback of a single bow propeller was that it would lubricate only one side of the hull. As a result, the new Finnish icebreaker was designed with two bow propellers which would produce a more powerful and, more importantly, symmetric flushing effect. Furthermore, a vessel with four propellers would be extremely maneuverable and capable of even moving sideways. Prior to the new Finnish icebreaker, only the 1947-built Canadian ferry Abegweit had been fitted with such propulsion arrangement. While the new ship was not the largest icebreaker in the world at the time, the power-to-displacement and power-to-beam ratios of the new Finnish icebreaker put her in a class of her own among icebreaking ships.
The construction of the first Finnish post-war icebreaker was awarded to Wärtsilä in 1948, but due to lack of funding the keel of the ship was not laid down at the Hietalahti shipyard until 29 May 1951.Jäänmurtajat Suomessa. The working name of the newbuilding was Into,Den nya havsisbryaren - ett teknisk framsteg. Suomen Laivasto, 3/1950. Pages 63–65. but when she was launched on 27 November 1952, the new Finnish icebreaker was christened Voima by Sylvi Kekkonen, wife of the Prime Minister and future President of Finland, Urho Kekkonen.Uusi jäänsärkijä laskettu vesille Hietalahden telakalla. Suomen Laivasto, 12/1952. Page 246. Her name, Finnish for "strength", had previously been given to one of the icebreakers that had been handed over to the Soviet Union after the war. The official sea trials were completed on 12 February 1954 and on the following day the icebreaker was handed over to the Finnish Maritime Administration. At the time of delivery, the 10,500-horsepower Voima also briefly held the title for the most powerful icebreaker in the world, surpassing both the old Soviet steam-powered polar icebreakers as well as the diesel-electric Wind-class icebreakers and USCGC Mackinaw which all had a propulsion power of 10,000shp. However, in the following spring the United States commissioned USS Glacier which, at 21,000shp, had twice the power of the Finnish icebreaker.
The new state-owned icebreaker generated widespread publicity and the follow-up orders allowed Wärtsilä to establish the Finnish shipbuilding industry as the world leader in the design and construction of icebreaking ships.Turunen and Partanen (2011), p. 40. After Voima, the shipyard delivered three icebreakers of similar design to the Soviet Union (Kapitan Belousov, Kapitan Voronin and Kapitan Melehov) and one for the Swedish Maritime Administration (Oden).Suurtunnustus jäänmurtajien rakentajillemme. Suomen Laivasto 12/1954, page 248. By the late 1980s, Wärtsilä had produced about 60 percent of the worldwide icebreaker fleet,Finland-Transport Equipment. Mongabay.com. including all Finnish icebreakers in service at the time.
Career
Early career
While the new icebreaker was being built, the state-owned icebreaker fleet had become a powerful strike weapon for Niilo Wälläri, the chairman of the Finnish Seamen's Union. By the early 1950s, the strikes had become so common that they were sometimes considered a normal part of the arrival of winter. It was even jokingly said that a new icebreaker strike could be predicted simply by looking at the thermometer—the "strike threshold" would be reached when the temperature dropped low enough for the seas to freeze.Sampo - The giant of the ice fields . When Wälläri announced a new strike in 1953, the Finnish Government decided to take action as the icebreaker strikes effectively stopped all foreign trade during the winter months, causing major losses for the Finnish industry. In Sweden, the state-owned icebreakers were part of the Swedish Navy and thus were not allowed to go on strike. On 9 February 1954, only four days before Voima was commissioned, it was decided to move the new icebreaker under the Finnish Navy, where it would replace the 77-year-old Von Döbeln as the supply ship for the torpedo boats during the summer months. During the icebreaking season, the ship would still be crewed by the Navy, but used to escort merchant ships under the command of the Finnish Maritime Administration.
The change of flag was postponed until the end of the winter season due to opposition from the Seamen's Union. When Voima was transferred to the Finnish Navy on 1 May 1954, the Seamen's Union announced that Finnish merchant ships, crewed by civilians, would not subject themselves to military authority by accepting assistance from a naval ship. As a result, the ports of Kotka and Hamina were effectively closed during the first months of the following winter, trapping a number of ships in the harbors, as Voima was the only icebreaker stationed in the eastern part of the Gulf of Finland. Eventually, the Government gave up and called Voima to Helsinki, where she remained until the spring. On 1 December 1955, Voima was transferred back to the Finnish Maritime Administration.Uusi Suomi, 11 February 1954. s. 10.
Although the commissioning of the new icebreaker did not go as planned, Voima still brought a long-awaited relief to the Finnish winter navigation. During the extremely difficult winter of 1956, she broke all previous records by escorting or otherwise assisting 616 icebound ships, among them the steam-powered icebreakers Sampo and Tarmo that had been immobilized by compressive pack ice. Voima also proved the superiority of two bow propellers in Baltic ice conditions and experiences from her first years in service were used to design the new Karhu-class icebreakers in the late 1950s. Voima remained the most powerful icebreaker in the Finnish state-owned fleet until the new 12,000 hp Tarmo-class icebreakers entered service in the mid-1960s.Turunen and Partanen (2011), p. 38.
Refitting The rebuilding and expanding of the Finnish icebreaker fleet continued until all Finnish ports could be kept open year-round.Jääsalo (1980). In the late 1970s, the first post-war icebreakers were approaching either mid-life update or retirement. As a result, the 25-year-old Voima was extensively rebuilt by Wärtsilä Helsinki Shipyard in 1978–1979 at a cost of about FIM 86 million,Pohjanpalo (1978), p. 182. 60% of the price of a new icebreaker of comparable size. In the refit, Voima received new hull plating and additional ice-strengthening, new main engines and a completely new superstructure to accommodate the crew, and her propulsion motors and electrical systems were completely refurbished. After the refit, Voima was practically a new ship with only web frames, bottom plating, forepeak and propellers remaining from the original ship and, at 14,000 shaft horsepower, the third most powerful icebreaker of Finland at the time. She returned to service on 10 October 1979.Jäänmurtaja Voima uudistettu. Navigator 11/1979.
During the refit, the hull of Voima was painted bright red in order to improve the ship's visibility in fog.Auvinen (1983), p. 202. However, the experiment was not continued after the first five-year period, and in the mid-1980s she was painted back to the traditional colors.
Later career
After the late 1970s refit, Voima resumed her duties as an escort icebreaker. As more powerful icebreakers entered service in the 1980s and 1990s, she has operated mainly in the Gulf of Finland. During the particularly mild winters of 1995 and 2002, she remained at stand-by at Katajanokka through the winter. Although Voima had been involved in minor collisions and other incidents in the past, she had not been grounded until 11 April 2003, when she ran aground while assisting a small German cargo ship in difficult conditions outside Helsinki. However, there were only minor dents in the hull plating and some damage to the bow propeller blades, which were repaired at Vuosaari shipyard on 14–17 April.
Following the reorganization of the Finnish Maritime Administration in 2004, the ownership and management of the state-owned vessels was transferred to a newly founded state-owned enterprise, Finstaship. Since 2010, the Finnish state-owned icebreakers have been owned and operated by the state-owned shipping company Arctia through its subsidiary, Arctia Icebreaking.. Arctia Shipping.