130 53 TK or 130 TK ("130 mm rifled, 53 length caliber, turret gun") is a Finnish fixed, heavy artillery piece, manufactured by Tampella. The caliber is 130 mm. 130 53 TK is the main weapon of the Finnish coastal artillery.
The maximum range with high-explosive fragmentation shells is 25 kilometers and with special sea target shells it is over 30 km. The initial velocity of the shot is around 860 m/s depending on the shell and amount of propellant used. When firing temporary bursts with auto-loader the gun can fire 3 shots in 20 seconds and up to 6 shots per minute during sustained firing. The gun weighs 16 tons (including shield) and the length of the barrel is 6 818 mm. The gun is manned by 3 NCOs and 7 servicemen.
The development of the 130 TK started in the 1970s and lasted for 10 years. In 1971, the Finnish national defence committee suggested that the then main current coastal artillery gun (152/50 T) would be replaced by the end of the 1970s. A development contract was signed with Tampella in 1975. It was decided that the calibre would be 130 mm, since the mobile coastal artillery used towed guns of same calibre (130 K 54). A prototype was constructed on the island of Isosaari in 1980, where test firing was conducted until 1983.
The Finnish Defence Forces signed a series production contract with Tampella in 1982. The first battery was installed in 1984 and the final in 1990. The spaces required for the gun, such as room for the gun crew and ammunition storage was built inside the base rock with concrete casemates for shaping. The 130 53 TK will probably be the last fixed coastal defence gun in the Finnish inventory.
Initially, there were no special sea target shells, instead, regular fragmentation shells were used with timed, immediate and delayed fuses for differences in desired effect. A first attempt to develop sea target shells failed in the 1980s, with the company going bankrupt. A fresh start was done in the beginning of the 1990s for payload shells similar to some anti-tank shells.
Targeting for these guns is done by a targeting team either using a laser range and direction finder or optically with triangulation (requiring two teams). The triangulation method is safer as there is nothing transmitted towards the target as in the laser rangefinder case. The coordinates (if laser acquired) or directional information in the case of triangulation are sent to a calculation unit which then calculates the targeting solution for the guns. This is a continuous (tracking) operation since the targets are moving. The gun itself can be directed manually with the data coming from the central calculation unit or fully automatically based on the data received via a data bus from the central calculator. The gun is also fully capable of autonomous operation with its own laser rangefinder and firing solution computer.