Spica class (1966)


HMS Spica in the Wasa Museum near Stockholm
Career
Ship type	Speedboat
Ship class	Spica class
Type ship	HMS Spica (T121)
units	HMS Spica (T121) HMS Sirius (T122) HMS Capella (T123) HMS Castor (T124) HMS Vega (T125) HMS Virgo (T126)
Shipyards	Götaverken (T121-123) Karlskronavarvet (T124-126)
Launch	1966
Commissioning	1966
Decommissioning	1989
home port	Karlskrona
Technical specifications
Displacement	210 t
length above all Waterline	42.45 m 39.9 m
width	7.2 m
Draft	2.6 m
drive	3 × Bristol-Siddeley Proteus 1282 gas turbines, each with an output of 4,250 hp 3 × controllable pitch propellers
Top speed	> 40 kn
crew	28
Main armament	6 × 53 cm wire-guided torped 61
Guns	1 Bofors gun 57 mm 2 machine guns 7.62 mm
More weapons	1 × 57 mm rocket launcher Sea mines / depth charges

The Spica class was a class of six torpedo speedboats ( Swedish : Torpedbåt ) of the Swedish Navy . From 1966 until the end of the Cold War , they were a central part of Swedish national defense.

history

In the 1960s, when the Eastern Bloc was seen as the main threat to Swedish neutrality, a successor to the Plejad class built by the German Lürssen shipyard was sought. The main task should be the defense of the long Swedish coast on the Baltic Sea with its shallow water and rugged coastline. The geographical conditions together with the lack of international ambitions as well as Sweden's limited financial means made the torpedo boat weapon system seem optimally suitable. After examining Norwegian, German and English types of express boats, preference was given again to the German Lürssen shipyard: Lürssen Sweden sold the design drawings of the Jaguar class , from which Sweden wanted to develop its own variant and build it completely independently.

Götaverken , a shipyard in Hisingen near Göteborg , received the order to further develop the Lürssen design . The construction contract for six boats was split 50% each between the Götaverken shipyards (now part of the Damen Group) and Karlskronavarvet (now Kockums and thus part of TKMS ). Götaverken built the three units Spica (T121), Sirius (T122) and Capella (T123), while Karlskronavarvet built the three boats Castor (T124), Vega (T125) and Virgo (T126). All units were named after stars.

With the end of the Cold War and the threat posed by the Warsaw Pact no longer there, the now outdated Spica-class boats - high-speed rocket boats had long since replaced torpedo boats - were no longer used. Therefore, all six boats were retired in 1989.

technology

When it was commissioned, the Spica class was one of the most modern warship classes in the world. It was revolutionary in various areas, in particular hull construction, drive concept and armament compared to its predecessors and the development template - the Pleiad class and the Jaguar class, respectively. At the same time, however, the Soviet Union heralded the next age, the age of the rocket speedboat, with its Komar-class and Osa-class speedboats.

Ship platform

In contrast to the German models, the hull was made of steel. The length on the waterline was 39.9 m, over all it was 42.45 m. The boats were 7.2 m wide and had a draft of 2.6 m. The water displacement was 210 t.

The crew consisted of 27 to 30 people; there were usually 28 men.

drive

Also in contrast to the German models, a pure gas turbine drive was installed according to British plans . Three gas turbines from the British manufacturer Bristol-Siddeley of the Proteus 1282 type, each with 4250 hp or 3170 kW, set three variable-pitch propellers in motion via three shafts. This enabled the boats to accelerate to over 40 kn (~ 74 km / h).

Two other smaller gas turbines, each with 224 hp from the manufacturer MTU, were on board for the power supply, each driving a generator.

Armament

The main armament was six torpedo tubes in caliber 533 mm for wire-guided torpedoes Torped 61. All six torpedo tubes were rigidly mounted in a position slightly angled from the longitudinal axis. A torpedo was carried in each of the tubes; there were no replacement torpedoes on board. As an innovation compared to previous German and Swedish torpedo boats, wire-guided instead of unguided torpedoes were used. This made it possible for the first time to influence the direction of movement of a torpedo even after it was launched, which increased the probability of a hit.

A 57 mm Mark I marine gun from the Swedish manufacturer Bofors was scaffolded as secondary armament . The weapon, the length of which is 70 caliber lengths , was able to fire 200 rounds per minute over an effective range of 8500 m. The maximum range was 17,000 m. These parameters allowed the effective use against sea, air and land targets.

In addition, two machine guns in caliber 7.62 mm and a rocket launcher in caliber 57 mm were available. The latter could fire flares or IR or radar decoys.

additional

Each of the Spica boats had NBC protection . The boats could be hermetically sealed and all the fresh air was passed through a special filter system.

In addition, the boats had a fire control system, which was very modern at the time, consisting of a fire control radar and a rather primitive computer. This enabled precise fire control solutions for the torpedoes to be calculated.

Whereabouts

All boats, except HMS Spica (T121), were scrapped after the end of their service life. The Spica , however, was opened to the public as a museum ship. Until 2002 she was in her former home port Karlskrona as a museum ship . Since 2002 it has been in the Vasa Museum near Stockholm during the summer months , where it can be viewed every weekend. In the winter months it is located in a naval base, where it is not open to the public. The Spica is still fully roadworthy and also makes trips in the summer months, which can be booked.