The infanterikanonvagn 91 (ikv 91), , was a high mobility

assault gun An assault gun (from , , meaning "assault gun") is a type of armored infantry support vehicle and self-propelled artillery, mounting an infantry support gun on a protected self-propelled chassis, intended for providing infantry with heavy di ...

that was developed to meet the operational requirements of the

Swedish Army The Swedish Army () is the army, land force of the Swedish Armed Forces of the Kingdom of Sweden. Beginning with its service in 1521, the Swedish Army has been active for more than 500 years. History Svea Life Guards dates back to the year 1 ...

. It was designed and manufactured by

Hägglund & Söner Hägglund & Söner (''Hägglund & Sons''), commonly known as Hägglunds, was a diversified engineering company based in the town of Örnsköldsvik, in Västernorrland, Sweden. Originally a furniture manufacturing company, it diversified into t ...

(whose military vehicle business is now

BAE Systems Hägglunds BAE Systems AB is subsidiary holding company for the Swedish assets of BAE Systems Land & Armaments, whose ultimate parent is the British defence contractor BAE Systems. The portfolio in 2020 contained the companies ''Systems C-ITS'', involve ...

) and employed common components with the

Pbv 302 Pansarbandvagn 302 (pbv 302), meaning roughly ''armoured tracked carrier vehicle 302'', is a Swedish high-mobility infantry fighting vehicle () used by the Swedish Army from 1966 to 2014. The vehicle was commissioned by the Swedish Army in 1961 a ...

armoured personnel carrier An armoured personnel carrier (APC) is a broad type of armoured military vehicle designed to transport personnel and equipment in combat zones. Since World War I, APCs have become a very common piece of military equipment around the world. Acc ...

series. The first prototypes of the ikv 91 were completed in 1969 with production running from 1975 until 1978. In total, 212 were manufactured.

Designation

''Infanterikanonvagn'' () is the Swedish post 1940s term for

, replacing the short-lived 1940s term ''stormartillerivagn'' () with the introduction of the ikv 72 in 1953. The number 91 in the name means that it was the first assault gun in the Swedish armed forces to feature a cannon in the 9 cm caliber category (91 = 9-1: 9 cm gun, 1st vehicle in category).

Design

The layout of the ikv 91 is similar to a large

light tank A light tank is a Tank classification, tank variant initially designed for rapid movements in and out of combat, to outmaneuver heavier tanks. It is smaller with thinner vehicle armour, armor and a less powerful tank gun, main gun, tailored for ...

. The ikv 91 is divided into three main compartments, the driver's station in the forward left hull, the fighting compartment located in the vehicle's midsection, and an engine compartment in the rear hull.

Armament

The main armament consisted of a

Bofors AB Bofors ( , , ) is a former Swedish arms manufacturer which today is part of the British arms manufacturer BAE Systems. The name has been associated with the iron industry and artillery manufacturing for more than 350 years. History Locate ...

''KV 90 S 73'' (Cannon, Wagon, 90 mm, Swe, m/73) 90 mm L/54 rifled low pressure gun, firing

HEAT In thermodynamics, heat is energy in transfer between a thermodynamic system and its surroundings by such mechanisms as thermal conduction, electromagnetic radiation, and friction, which are microscopic in nature, involving sub-atomic, ato ...

and HE rounds. A sloped revolving turret gave protection against projectiles up to 25 mm in calibre. The main gun had an elevation of +15° and depression of −10°. The barrel was equipped with a fume extractor. Additional armament of the ikv 91 included two 7.62 mm Browning machine guns; one in a coaxial mounting, and the second on a pintle attached to the commander's cupola. Two 71 mm Lyran flare mortars were mounted on the turret along with a set of smoke dischargers (usually 12). The vehicle was equipped with a

laser rangefinder A laser rangefinder, also known as a laser telemeter or laser distance meter, is a rangefinder that uses a laser beam to determine the distance to an object. The most common form of laser rangefinder operates on the time of flight principle by ...

night vision Night vision is the ability to see in low-light conditions, either naturally with scotopic vision or through a night-vision device. Night vision requires both sufficient spectral range and sufficient intensity range. Humans have poor night v ...

(goggles) and a computerised fire-control system for increased first-round hit probability. The ikv 91 fired at a rate of 8 rounds per minute and 59 rounds of 90 mm ammunition were carried internally. The vehicle was also capable of firing while in water, with the water absorbing most of the recoil. The turret itself has a small hatch that can be opened by the loader to eject used cartridge cases to prevent clutter in the vehicle.

Mobility

With wide tracks and a high

power-to-weight ratio Power-to-weight ratio (PWR, also called specific power, or power-to-mass ratio) is a calculation commonly applied to engines and mobile power sources to enable the comparison of one unit or design to another. Power-to-weight ratio is a measurement ...

, the ikv 91 offered exceptionally good off-road mobility. The low

ground pressure Ground pressure is the pressure exerted on the ground by the tires or tracks of a motorized vehicle, and is one measure of its potential mobility, especially over soft ground. It also applies to the feet of a walking person or machine. Pressure ...

enabled the ikv 91 to operate through summer

taiga Taiga or tayga ( ; , ), also known as boreal forest or snow forest, is a biome characterized by coniferous forests consisting mostly of pines, spruces, and larches. The taiga, or boreal forest, is the world's largest land biome. In North A ...

and winter snow. The vehicle was fully amphibious with little preparation by the crew. Screens would be erected to stop water from entering the engine and the cabin compartment with a vane to protect from oncoming waves. The vehicle weighed 16.3 tonnes and had a crew of four. It was powered by a Volvo 12 liter, 330 hp, diesel engine. The maximum road speed was and the range on roads was about .

Retirement

The ikv 91 was retired from the Swedish army in the late 1990s – early 2000s due to budget cuts among others and was partly replaced by the

strf 90 The Combat Vehicle 90 (CV90) (, strf 90 or Stridsfordon 90) is a family of Swedish tracked armoured combat vehicles designed by the Swedish Defence Materiel Administration (FMV), Hägglund & Söner and Bofors during the mid-1980s to early 1990 ...

combat vehicles and

Leopard 2 The Leopard 2 is a third generation German main battle tank (MBT). Developed by Krauss-Maffei in the 1970s, the tank entered service in 1979 and replaced the earlier Leopard 1 as the main battle tank of the West German army. Various iterat ...

tanks. When in active duty, the ikv 91 was assigned to the Swedish infantry brigades, which had one company of 12 vehicles each. The 10th Mechanized Brigade had two companies in the 1980s. In the late 1980s and early 1990s, the 10th Mechanised Brigade had its ikv 91 replaced with Centurion tanks (Stridsvagn 102R & 104) and in 2000, all Swedish infantry brigades were disbanded.

Ikv 91-105

During the 1980s it became clear that the low velocity HEATFS-firing gun of the ikv 91 was not up to the task of fighting the new generations of Soviet made tanks. Thus plans were made to replace its 90 mm gun with a 105 mm gun or potentially even a TOW missile launcher. This was however not followed through in Swedish interests as it required heavy modifications and a new turret. The idea was put on hold until the 1990s when it became obsolete as the role of the ikv 91 could be filled by new

strv 122 Stridsvagn 122 (strv 122, ) is a Swedish main battle tank that, like the German Leopard 2A5, is based on the German Leopard 2 Improved variant using such newer technology as command, control, and fire-control systems, reinforced armour, and l ...

main battle tanks and

infantry fighting vehicles. Besides Swedish interests, a prototype armed with a 105 mm gun was made in 1983 for export to India, simply named the ikv 91-105. The main gun was a fully stabilized Rheinmetall Rh 105-11 super-low recoil gun in a new turret. The weight was 18 tons and the speed in water was increased to 12 km/h from the regular ikv 91. It had an IR system by SAAB which gave it full night capability. Both the gunner and commander had monitors and could fire the main gun. It was marketed for export and was tested by both India and the United States but was not purchased.

References

* 'Battle Tank' - Copyright 2006 by Boulevard Entertainment Ltd.
IKV-91 - Amphibious light tank