The Tampella 100 PSTK (from

Finnish Finnish may refer to: * Something or someone from, or related to Finland * Culture of Finland * Finnish people or Finns, the primary ethnic group in Finland * Finnish language, the national language of the Finnish people * Finnish cuisine See also ...

, '100 millimetre anti-tank gun'; Tampella project name ) is a Finnish towed 100 mm anti-tank gun, designed in the 1980s by

Tampella Oy Tampella Ab was a Finnish heavy industry manufacturer, a maker of paper machines, locomotives, military weaponry, as well as wood-based products such as packaging. The company was based mainly in the Naistenlahti district of the city of ...

. It was designed for commonality with the

D-10T The D-10 is a Soviet 100 mm tank gun developed in late World War II. It originally equipped the SU-100 tank destroyers and was later selected for the T-54/T-55, T-55 tank, equipping these as late as 1979. On the T-55 the D-10 continues to be ...

tank gun, in use by the

Finnish Defence Forces The Finnish Defence Forces ( fi, Puolustusvoimat, sv, Försvarsmakten) are the military of Finland. The Finnish Defence Forces consist of the Finnish Army, the Finnish Navy and the Finnish Air Force. In wartime the Finnish Border Guard (whic ...

in the

T-54 The T-54 and T-55 tanks are a series of Soviet main battle tanks introduced in the years following the Second World War. The first T-54 prototype was completed at Nizhny Tagil by the end of 1945.Steven Zaloga, T-54 and T-55 Main Battle Tanks ...

and

T-55 The T-54 and T-55 tanks are a series of Soviet main battle tanks introduced in the years following the Second World War. The first T-54 prototype was completed at Nizhny Tagil by the end of 1945.Steven Zaloga, T-54 and T-55 Main Battle Tank ...

tanks, as well as the 100 56 TK coastal artillery piece. However, due to multitude of reasons it never went into serial production.

Development

In 1986 chief of the Infantry Office of the Finnish Defence Command, Lt. Col. Paavo Kuronen, brought out the question of a range gap in anti-tank weaponry, between contemporary man-portable anti-tank weaponry and anti-tank missiles, ie. 400 and 1000 metres, as well as the multitude of armed vehicles and their rising performance against infantry on the contemporary battlefield. In addition, the FDF Defence Command was worrying of the lack of suitable anti-tank weaponry at the aforementioned ranges to match the increasingly more common

explosive reactive armour Reactive armour is a type of vehicle armour that reacts in some way to the impact of a weapon to reduce the damage done to the vehicle being protected. It is most effective in protecting against shaped charges and specially hardened kinetic ener ...

and layered

composite armour Composite armour is a type of vehicle armour consisting of layers of different material such as metals, plastics, ceramics or air. Most composite armours are lighter than their all-metal equivalent, but instead occupy a larger volume for the sa ...

. At the time, Finland was also in the process of scrapping its stock of obsolete 75 PstK 40 anti-tank guns (German

7.5 cm Pak 40 The 7.5 cm Pak 40 (''7,5 cm Panzerabwehrkanone 40 -'' "7.5cm armour defence cannon 90") was a German 75 millimetre anti-tank gun of the Second World War. The gun was developed in 1939–1941 and entered service in 1942. With 23,303 ex ...

). The existing 95 S 58-61 recoilless rifle was theoretically suitable, but its backblast was a remarkable downside, and the old ammunition types didn't offer much to defeat the reactive and composite armour. To this dilemma, the Infantry Office proposed a new anti-tank gun firing modern armour-piercing fin-stabilized discarding sabot (APFSDS) ammunition, a system which could be manufactured entirely in Finland (as opposed to the American and Soviet anti-tank missile systems currently in use by FDF). The FDF Defence Command Infantry Office created a draft of specifications and presented them to Tampella in spring 1986. The new anti-tank gun was to use the barrel and breech block (complete barrel assembly) of the Soviet D-10T (which was in use by FDF in the existing T-54, T-55 and 100 56 TK systems), with a new carriage, cradle (including recoil system) and traverse unit. Thanks to this, it could use the new

Mecar Mecar is a Belgian weapon and ammunition manufacturing company headquartered in Petit-Roeulx-lez-Nivelles, Hainaut Province. Mecar is responsible for creating weapons ranging from grenades to lightweight anti-tank cannons. The company was establi ...

APFSDS which was introduced to the T-55 in the FDF T-55M project. It was to have an

auxiliary power unit An auxiliary power unit (APU) is a device on a vehicle that provides energy for functions other than propulsion. They are commonly found on large aircraft and naval ships as well as some large land vehicles. Aircraft APUs generally produce 115& ...

(APU) for assisted movement, a shield to protect from small arms fire and both day and image intensifier based night sights. Its combat weight was to be under 3 tonnes, traverse 60° (±30° from centreline) and elevation -10° to +20°, according to the initial specifications. After initial calculations by Tampella, FDF Defence Command ordered Tampella to design the gun in May 1987. Tampella ordered the design of the carriage from Sisu Defence, while Tampella concentrated on the design of the gun itself. After the design was ready in November 1987, a prototype gun was ordered by FDF in February 1988, and the final specifications were given. The prototype was delivered in August 1989 after some issues, and field trials were held from January to June 1990 in the Lapland Jaeger Battalion at

Sodankylä Sodankylä (; sme, Soađegilli ; smn, Suáđigil; sms, Suäʹđjel) is a municipality of Finland. It is located in the region of Lapland, and lies at the northern end of Highway 5 ( E63) and along Highway 4 ( E75). The Kitinen River flows nea ...

and to the end of 1990 in the

Armoured Brigade The Armoured Brigade ( fi, Panssariprikaati) is a Finnish Army training unit located in Parolannummi, near Hämeenlinna, in southern Finland. The brigade specialises in training tank, armoured and anti-aircraft troops. In case of mobilization, the ...

Hämeenlinna Hämeenlinna (; sv, Tavastehus; krl, Hämienlinna; la, Tavastum or ''Croneburgum'') is a city and municipality of about inhabitants in the heart of the historical province of Tavastia and the modern province of Kanta-Häme in the south of F ...

. The trials proved many serious issues: the APU was underpowered for the gun, steering the carriage was difficult and the towing bar of the carriage proved to be too weak, as it fractured repeatedly in use, and the muzzle brake broke due to the pieces of the sabot hitting it. The bore axis was also considered to be too low. The trials were also hindered by lack of spares for the single prototype gun and trivial technical issues such as oil leaks. However, the performance of the gun was considered excellent and the gun was stable in firing position. The serial production of the gun was intended to be started in 1991, but unsurprisingly, due to the technical issues and a new assessment on the viability of towed anti-tank guns, in July 1991 the FDF Chief of Training Lt. Gen. Matti Kopra officially terminated the project. The prototype gun was stored in Armoured Brigade, and has been displayed sporadically to the public. Parts of the recoil mechanism were used in the Patria

AMOS Amos or AMOS may refer to: Arts and entertainment * Amos Records, an independent record label established in Los Angeles, California, in 1968 * Amos (band), an American Christian rock band * ''Amos'' (album), an album by Michael Ray * ''Amos' ...

and NEMO mortar systems, as Tampella Defence was first merged to FDF Vammaskoski factory after its bankruptcy and subsequently to Patria.

Technical details

*Mass under *Length (transport)
(combat) *Height *Width *Ground clearance *Driving speed *Towing speed *Crew 1+7 *Rate of fire 6 rpm *Shield to protect from small arms fire *NIFE RS-420 telescopic day sight *Image intensifier night sight

Gun

*Barrel from

: **Calibre **Barrel assembly length L/56 **Barrel length L/54 **Rifled bore length **Bore axis height (combat, 0° elevation) **Breech semi-automatic horizontal sliding block *Elevation -10° to +20° *Traverse ±30° from centreline *Hydro-pneumatic recoil system

Ammunition

*JVA 3908 (Mecar M-1000 APFSDS-T) **Round weight **Muzzle velocity **Effective firing range *JVA 3900 (UBR-412D APCBC-T) **Round weight **Muzzle velocity *UOF-412 HE **Round weight **Muzzle velocity

Carriage

*APU engine

Rotax Rotax is the brand name for a range of internal combustion engines developed and manufactured by the Austrian company BRP-Rotax GmbH & Co KG (until 2016 BRP-Powertrain GmbH & Co. KG), in turn owned by the Canadian Bombardier Recreational Produc ...

635 **Two-stroke petrol engine **Power output at 5,300 rpm **Torque at 4,700 rpm *Traction wheels 14.5x20 **Double Rexroth hydraulic pumps for power transmission **

Valmet Valmet Oyj is a Finnish company and a developer and supplier of technologies, automation systems and services for the pulp, paper and energy industries. Valmet has over 200 years of history as an industrial operator. Formerly owned by the S ...

Black Bear 1600/800 wheel hub motors **Drum brakes *Trail wheel 6.5x16 *Hydraulic suspension

Operators

Former operators

* – 1 prototype in trials in 1990, withdrawn at the end of the year.

References

{{reflist

External links

Presentation of the Tampella anti-tank guns
– includes photos of the 100 PSTK. Artillery of Finland Anti-tank guns of the Cold War 100 mm artillery