127 mm gun.
HARPOON anti-ship missile
SEA SPARROW anti-aircraft missile.
40 mm machine gun.
533 mm torpedoes
20 mm Orlikon maschine gun
Depth charges Type G.
127 mm gun
Originally the main armament of the Frigate was four 127 mm (5 inch) guns mounted in 2 twin turrets on the fore deck. The update in 1979 meant that one of the turrets was replaced by HARPOON missile launchers. The gun is an old American twin-barrel able to engage targets in the air, on the surface and on land (shore bombardment). It was given the Danish type designation M/60.
127 mm gun.
The gun used split ammunition. The weight af a shell was 24 kg. and the cartridge was 3,3 kg. By lift from the ammunition handling compartment the shell and the cartridge (propelling charge) were brought up to the gun where they manually were placed on the rammer cradle from where they were joined and rammed into the chamber of the gun. Then the breach was closed, and the gun was ready to fire. The guns could be directed remotely from one of the fire control centers or locally, where laying to the side was limited due to the heavy weight (36 tons) of the gun. Similarly the gun could be fired from the fire control or locally from the left side of each gun.
The gun had 2 aiming systems - a binocular for the side and height layer and a target designation sight for the gunner. Each gun was manned by 12 persons. After firing the recoil was stopped by hydraulic brakes on either gun, the cartridge was expelled onto the deck via a slide aft of each gun, and the gun pipe was vented to remove any gasses from the gunpowder. Each gun could fire up to 15 shells per minute. After 1 minute of firing the pipe had to be cooled before firing could be resumed. The velocity of the shell was 795 m/sec and at an elevation of 40⁰ the max. range was app. 16 km. Against aircraft the gun could be elevated to 85⁰. Normally the Frigate stored 1,660 shells (High Explosives and Star Shells).
Sea Sparrow air defense missiles
The Frigate's Sea Sparrow Missile launcher with its 8 missiles of the type RIM 7M is placed on the aft deck. On the port side of the superstructure right in front of the launcher you will find a magazine with additional 9 missiles. In and on the superstructure aft of the system are the system's two fire control centers. The Sea Sparrow missile is constructed for shooting down enemy aircraft or missiles. They are 3.7 m long, have a diameter of 20.3 cm and a weight of 226.8 kg. Their explosive charge is 15 kg. Their speed is Mach 2.5 corresponding to 2,990 km/h, and their max. range is 18 km. The target is illuminated by one of the two large fire direction radars, and after launching the missile follows the radar beam to the target.
Sea Sparrow air defense missiles.
Fire direction takes place from two fire controls if two enemy aircraft or missiles are to be engaged simultaneously. After the Ops-room had designated the target, one of the two fire control centers took over the illumination with its fire control radar. When the radar's very concentrated beam had locked on the target and the computers indicated a hit range of app. 16 km the first missile was launched. The Sea Sparrow centers had a manning of five persons.
HARPOON surface-to-surface missiles
The main weapon of the Frigate was 8 homing HARPOON Type RGM-84A anti-ship missiles. The system was installed at the up-date in 1977-79, where it replaced one of the twin 127 mm guns. The missile is 4.83 m long with a diameter of 34 cm and a range of 92 km.
The radar search antenna is placed in the front and behind that there is an auto pilot with a radar height finder. Behind there is a turbine jet engine and a rocket engine which is released upon sending the missile up to a height of 400 m and giving it a speed of 1,000 km/h. The missile will then follow the ordered course at a flying height of app. 5 meter. When the approaching its target the search radar is activated and the first major radar echo is attacked. The missile has an explosive charge of 100 kg and percussion fuse so the detonation takes place inside the target.
HARPOON surface-to-surface missiles.
The missiles are kept in a so-called "cannister" from where each of the two launchers can fire the missiles. All orders to the missile and the actual launching takes place from a special console in the Ops-room. After launching the Frigate has no control of the missile.
40 mm machine gun
The four 40 mm machineguns in the anti-aircraft mount (LvSa, model 48) primarily were used as close air defense against hostile aircraft and missiles. The guns were loaded with packs of four cartridges and could fire app. 300 rounds/min. Each grenade weighed 1 kilo, and two types of ammunition were available: a type with percussion fuse against maritime targets and a type with proximity fuse against aircraft. While the percussion fuse was not activated till the grenade hit the target, the proximity fuse was fitted with a small transmitter/receiver which made the grenade explode close to the target (aircraft or missile). On detonation the grenade, sprayed out a large number of small round fragments of tungsten carbide penetrating the target at very great velocity.
The muzzle velocity was 3,600 km/h, and the gunnery crew consisted of 5-6 men of which 2 were loading the gun. Max. range was 12,600 m. The mount could be turned sideways at a speed of 90⁰ per second, and elevated 45⁰ per second.
The guns could be laid from the artillery center or a gyro control, but they could also be controlled from a sighting control station at the left side of the mount. As a last option, if all the other sighting systems should go down, it could be laid by hand by an elevation handle on the left side and a side directing handle in the right side. The gun was placed in a glass fiber cupola instead of behind a shield. Normally the four guns had a total of 3,400 cartridges in the magazine. Range 12.000 meters at 45 degree elevation.
20 mm machine guns
At the end of the 1980s the Frigate was armed with four 20 mm machine guns Type M/42. The guns were directed by hand and had limited effect, but they were part of the close defense system of the Frigate and could be used against aircraft and fast motor boats like such guns were used by the USS Cole in Yemen, where 17 of the crew were killed by an attack from a motor boat. The gun was operated by one person. It was not coupled to the fire direction system, but manually laid via a ring sight.
533 mm torpedoes
The Frigate could fire two types of torpedoes, the old but modified type T1T and the modern Type TP612. T1T is a German 533 mm torpedo of which the Navy bought a large number after the Second World War. In the 1960s the torpedo was modified for wire guidance. In the torpedo and in the launching tube on the Frigate a wire spool is mounted, and millimeter thin a wire is paid out during the run of the torpedo, so that the wire is lying completely still in the water. Via the wire the operator could turn the torpedo so that it hit the selected target. The torpedo has a length of 7.19 m, weighs 1,520 kg and has an explosive charge of 300 kg. At 30 knots it has a range of 12 km, and at 40 knots of 7 km.
533 mm torpedotubes
The torpedo TP612 is a Swedish wire-guided torpedo which the Navy started using in 1971 as a replacement of the older Type T1T torpedo. The torpedo did not use compressed air in the engine for combustion, but highly concentrated peroxide. This demanded special precautions for maintenance and transport, but it meant that the torpedo did not leave a trace of telling air bubbles when fired. The TP612 was surprisingly accurate, too, as its side track error was less than 0.3⁰ and its speed varied less than 0.3%.
The torpedo had a range of 18.5 km at a speed of 45 knots and 24 km at 30 knots. It weighed 1,755 kg and carried an explosive charge of 235 kg. In 1973 the Fregate was armed with 4 torpedo tubes in double mounts. The tubes could be turned hydraulically 15⁰ over the side of the frigate and launched by air from a launching kettle or by a 600 g gunpowder cartridge. Normal firing was by air via an electric impulse from the TORCI system in the Ops-room. Alternatively the torpedo could be launched "locally" by pressing a handle mounted on the tube.
The torpedoes ran at the pre-set depth and could be steered sideways from the TORCI in the Ops-room via the thin cable which was spooled off from the torpedo and the Frigate, respectively, so that the wire was lying completely still in the water. The TORCI displayed a radar picture of the target as well as the calculated track of the torpedo. If the torpedo did not hit its target at first passage, it could be turned and a new attempt made.
The six Type G depth charges on board the Frigate were to be used against submarines. They were barrel-shaped and set to explode at the depth where the submarine was supposed to be. To damage a submarine the charge has to detonate within 4-6 m from the submarine, but detonations within 12-15 m were expected to damage the submarine by shaking loose the batteries, engines etc. from their foundations. Detonations at a longer distance than 15 m would primarily have a mental effect on the crew.
During the Cold War depth charges were used as a warning signal telling trespassing Soviet submarines to leave Danish territorial waters.