Cold War Swedish Prototypes

Stridsvagn 2000 T140/40

Kingdom of Sweden (1984)
Main Battle Tank – 1 Wooden Mock-up Built

Sweden’s MBT that never was

The Strv 2000 project was intended to fulfill Sweden’s need for a modern main battle tank (MBT). In 1984 the Swedish government began to look into replacing the Strv 103 and Strv 104 tanks it had in service.
The intent was to assess the feasibility of a Swedish design, as well as to look foreign designs. These were to be either to be built under license in Sweden or ordered from a foreign manufacturer. The vehicle that would be chosen would come into service around the year 2000, hence the name of the Swedish prototype.

The Millennial MBT

In the late 1970’s, the Swedish Military began to shift from a more defensive focus in their armored fighting vehicles to more of an emphasis on main battle tanks.  The driving force behind this call for a new tank was Colonel Bjorn Zickerman, who was also instrumental in helping develop the Ikv 91 in the 1970’s.
In order to find a new vehicle, the idea was to compare several modern MBTs such as the M1A1 Abrams or Leopard 2, to a prototype tank developed within Sweden. In 1984, work commenced on the Strv 2000 project.
Strv 103 and a Centurion
The tanks in service with the Swedish army at the start of the Strv 2000 project, the Strv 103 and the Strv 104 (modified Centurions)
Sweden had several requirements as to what the Strv 2000 would need to be, regardless if it was a foreign vehicle or developed domestically. This new vehicle was to have an emphasis on crew safety, as well as the survivability of the vehicle. These were to take precedence over all other elements such as armament and mobility. In order to keep training simple, the vehicle also had to be simple to operate.
In addition to this stipulation, there were three main objectives that the Strv 2000 had to meet. Firstly, it would need to be able to fire in any direction while moving. This could be of concern for lighter tanks, or for tanks with a very large and cumbersome main weapon. Secondly, it was to have good visibility all around the vehicle for the crew inside. Thirdly, there had to be a high survival rate of both crew and the vehicle if the ammunition storage compartment were to be hit or explode.
In order to develop a domestic design, Swedish defense industries first looked back to recent Swedish AFV prototypes under the UDES project in the 1970’s. The prototypes developed in 1984 were designed to meet “Hotstridsvagnar”, or potential and projected AFV threats that may be faced in the future. The two levels used in this project were Hotstridsvagnar VI, equivalent to the T-80, and Hotstridsvagnar VII, equivalent to the second generation T-80.
Making comparisons to these vehicles, and finding how to best combat them guided the development of Swedish prototypes. In 1985, the industry was able to present 3 different ideas for a modern tank built in Sweden. The first would be a traditional MBT layout (turreted tank) with 4 crew members, the second was an MBT with a compact turret and 3 crew members, while the third proposal was another turreted MBT with 3 crew members.


Initially, the use of the 120 mm (4.72 in) cannon was seen as most favorable for the Strv 2000 project. However, some thought was put into using a larger 140 mm (5.51 in) cannon in order to achieve better armor penetration. The 140 mm cannon was shown to have 25% to 50% better armor penetration (up to 800 mm/2ft7 of penetration) and twice the muzzle energy of the 120 mm cannon. However, it also came at a cost. First of all, the 140 mm rounds were very large, so fewer of them could be carried and an autoloader was essential.
It was also an unproven weapon for an MBT. It would require a lot of time, money and effort in order to get a properly functioning weapon system. In order to address the issues of a limited number of rounds stored for the 140 mm gun, a proposal was made to mount a 40 mm (1.57 in) cannon to the side of the main gun. This would serve to engage targets that did not require the larger weapon. This concept could greatly enhance the performance of the tank, as it would have a heavy hitting weapon for well-protected targets, and a smaller but very effective and well-supplied weapon for softer targets.


Armor for the Strv 2000 had to have excellent ballistic protection as well as a low infrared signature. The Swedish solution for increased protection was to have a basic steel hull with armor sections added to it externally. These blocks of armor would be easy to replace in the event of a hit and could absorb more energy. In 1989, a composite armor research project was begun, which looked at how different materials and combinations of materials reacted with different projectiles. In order to best protect the crew, the engine was placed in the front, with all the crew in the back. The ammunition storage also was contained separately from the crew, and would explode outwards from the vehicle if ignited. This was done with the use of “blow out” panels that would vent the explosion.
The armor layout of the Strv 2000, clearly showing the side and frontal modular armor panels. These were practically ERA blocks, but also effective against kinetic penetrators. Credits:


After Sweden had assessed the M1A1 Abrams and Leopard 2 in 1989, it was found that the older requirements, such as the maximum ground pressure and deep wading capabilities, were made obsolete by newer tank technologies. The new MBTs were shown to have powerful enough engines, strong and efficient transmissions, and tracks good enough to allow them to traverse the difficult Swedish terrain with ease. Thus, fording and track width requirements were dropped from the needs of the domestic design.


A rendition of one of the Strv 2000 designs, probably the T120/40The drawer ammo compartment of the Strv 2000The Strv 2000 O140/40 designThe Strv 2000 L140 design.Diagram showing the components of the T140/40The three competitors for the Swedish MBT role, the Strv 2000 T140/40, the M1A1 Abrams and Leopard 2A4Side view of the Strv 2000 mock-up

The T140/40 design

The T140/40 version was the only one to be turned into a full-scale model and came nearest to achieving production of all the Strv 2000 designs. It was to be armed with a 140 mm cannon, mounted centrally, and a 40 mm autocannon independently mounted on the left side. Two machine-guns are also featured in the plans, one coaxial with the 40 mm and one on the commander’s hatch.
Both the cannons were served by an autoloader, 29 shots being available for the main gun, and 148 for the secondary. The large caliber ammunition was held in a drawer-like storage container at the rear of the hull, which could be ejected in case of detonation. The vehicle also had two flare launchers, which were to be used to illuminate targets at night. The vehicle was not fitted with night vision equipment.
The T140/40 mock-up, showing the secondary 40 mm autocannon. Credits:
The frontal protection should have been equivalent to 800 mm of RHA against kinetic penetrators and 1200 mm against HEAT rounds. This was achieved with the use of modular ERA plates which were placed at a certain distance from the body. Also in order to help protect the crew, the 1500 hp engine and the transmission were placed at the front of the vehicle.
The 3 crewmembers were all placed on the right side of the vehicle, with the driver in the hull, the gunner in the turret front and the commander just behind him, having the most elevated position. It can be argued that there is a rather large blindspot on the left side of the vehicle.
However, in the end, the production of the Strv 2000 T140/40 would have been costly and slow to implement, and given the changing geopolitical climate, it was abandoned in favor of a foreign design.

Other variants


This vehicle was designed to be more conventional and use already existing parts and knowledge. This meant that it would have a 120mm main weapon and a crew of 4. The focus of this design was to show an alternative vehicle that could be developed and produced quickly and cheaply.


This vehicle would be based on a strengthened Strf 90 chassis, but have a different turret mounted on top. This meant that it would be cheap and easy to build, but would sacrifice functionality and protection. The turret was intended to house a 140mm gun with an autoloader. Due to its large weapon but weak armor, it would most likely fill more of a tank hunter role rather than that of an MBT.


This was a design incorporating an unmanned turret that would have housed a 140mm main weapon along with a 40mm cannon, just like the configuration in the T140/40 and L140. This would be a great benefit as it would reduce the size of the vehicle, thus creating a smaller target, as well as reducing the chance of the crew being harmed by a hit to the turret.

Other variants

The T120, T120/40 and L120 were also evaluated, but seen as unfit and quickly abandoned.

An official model of the Strv 2000 T140/40 showing a different secondary armament configuration. Image courtesy of Per Kjelltoft and Ed Webster.

Choosing the Strv 2000

In 1987, a report was published outlining the recommendations with regards to choosing the next MBT for Sweden. The report suggested that Sweden pursue the T120B and 140/40 prototypes, but still keep the option for a foreign tank purchase open in case if plans for government spending were to change in the future. If the military budget were to be cut, it would be much cheaper to pursue a foreign vehicle. If this was the case, options should be kept open for Swedish industry to build the vehicles, or at least components of them, as well as build any desired variants. This would be done so as to not weaken the strength and skill for military industry within Sweden.
The Leopard 2A4 was chosen as a stopgap as the Strv 121 in place of the local designs. Rather than production these were on lease from Germany before the improved Leopard 2 could be delivered in sufficient numbers.
Another report was issued in 1990. In those 3 years, the military continued looking into which foreign vehicles could be bought, as well as fleshing out the T-140/40 prototype. The choice was dependent on the military budget. Since the T140/40 had a lot more work ahead of it to actually get to a functioning prototype and have an industry set up to build it, it would be a slow process and require a lot more money than deciding to go for another vehicle.
In 1991, a unanimous decision was made to purchase the Leopard 2 and build it under license in Sweden. This was seen to be the best compromise, as it gave Sweden a satisfactory vehicle at a cheaper cost than developing their own, but the industry would still benefit as it would be built locally.

An article by Eric Matzner


The best source for the Strv 2000, the Ointres site (in Swedish)

Strv 2000 T140/40 specifications

Dimensions 10,2(oa)/6.8(hull)x 3.7 x 2.26 m (40’1”x 14’5” x 88’9”)
Total weight, battle ready 52 tons
Crew 3 (driver, gunner, commander)
Propulsion MTU 883 12cyl diesel, 1500 hp (1100 kW), 28.84 hp/tonne
Suspension Torsion bar
Speed (road) 70 km/h (44 mph)
Range 500 km (310 mi)
Armament 140 mm (5.51 in) auto-loaded gun
40 mm (1.57 in) auto-loaded gun
2×7.62 mm (.3 in) machine-guns
Armor (RHA equivalent) Front: 800 mm (2’7”) vs AP, 1200 mm (3’11”) vs HEAT
Side: 90 mm (3.54 in) vs AP, 450 mm (1’6”) vs HEAT
Total production Mock-up built

A fictional Strv 2000 T140/40 in service with the Swedish army.

Strv 2000 T140/40
by Arkhonus

Cold War Swedish Prototypes

UDES 15/16

Kingdom of Sweden (1970)
Light Tank – 1 Wooden Mock-up Built

Origins of UDES

In the 1970s, the Swedish government began working on a project to find suitable replacements for their armored vehicles and to develop new technology for armored vehicles. The project was called “Underlagsgrupp Direkt Eld Stridsfordon” or UDES, which can translate to “Basic Data Studies Group Direct Fire Combat Vehicle”. The idea was to test several new ideas for armored vehicles from within Sweden, as well as to test vehicles designed in other countries and compare their capabilities as a fighting machine in order to decide what would best meet the needs of the Swedish military.

The UDES 15/16 and UDES 15/16 TR

The FMV (the Swedish defense material administration) contacted the companies Bofors and Hägglunds to produce a light armored vehicle with certain specifications. It was to be cheap, have a turret but maintain a low profile, weigh about 20 tonnes, share parts with existing vehicles, have 10° of gun depression, and be armed with a 105mm gun with an autoloader. Both companies were to submit several designs and the FMV would choose the best.
Bofors came up with the UDES 14-2, and Hägglunds designed the UDES 14E. In 1974 these two projects were re-designated into UDES 15 and UDES 16, and were then combined into the UDES 15/16. For production, the chassis was planned to have hydraulic suspension which would be used to increase the depression of the gun to -10°. Technical drawings, as well as a full scale mock up, were completed, but it is unknown if a turret was ever actually produced.
This vehicle would have been intended for a fast highly mobile anti-tank role. The armor on the chassis would have been minimal, while armor on the turret would have been somewhat thicker.
This vehicle would not have been intended to take enemy armor head on, but instead be able to strike enemy vehicles and move quickly thereafter to avoid being hit in return.

UDES 15/16 TR

It was decided to mount the UDES 15/16 turret on an Ikv 91 chassis to test its performance on an already existing platform. This vehicle would be called the UDES 15/16 Tornrigg, or TR. The main differences are that it would only have had -5° gun depression as it would not have had the hydraulic suspension planned for the UDES 15/16 chassis, and that it would lack the rear ammunition storage bins. It is very unlikely this vehicle made it past the design stage.

Fate of UDES

It is unknown what happened to this project. All that is known for sure is that the UDES 15/16 TR was never put into production. The Swedish military probably learned a lot from the UDES projects, and these designs probably had a large influence on future military vehicles developed within Sweden.

Author’s note

This article relied heavily on a few sources that are not easy to verify. This article is intended to show the best information that was found but may still provide information that does not represent the truth or the truth in its entirety. If you have an issue with the information we have presented here, please let us know, or help us in finding better information.


Article on Swedish turreted tank destroyers on RSR
Article on the UDES projects on RSR
The second part of the above article
Very good source on the UDES project (in Swedish)
Some documents on the World of Tanks forum
UDES 15/16Full scale mock up of UDES 15/16Technical drawing of UDES 15/16 TR. Note the differences in chassis and turret placement from the UDES 15/16, as well as the lack of rear mounted ammunition bins.Technical drawing of UDES 15/16The turret drawing can be for either the UDES 15/16 or the UDES 15/16 TR as they only differ in the chassis used. The second column in the table beside the turret shows the armor thickness at different points of the turret.Proposals for the UDES 14 project from Bofors

UDES 15/16 specifications

Armament 105mm L45 or L50 gun with autoloader
Weight 25-30 tonnes
Crew 3
Armor 8-160 mm
Production 1 mock-up

UDES 15/16 TR
by Arkhonus
UDES 15/16 TR
UDES 15/16 TR – click to see a what-if rendition in camouflage.

WW2 German Tank Destroyers

7.5 cm PaK 40 auf Raupenschlepper Ost (RSO)

German Reich (1943)
Tank Destroyer – Estimated 80-90 Built

From Hauler to Fighter

As the German army faced ever increasing numbers of Allied armour, more ways were found to place anti-tank weaponry on already existing chassis, in order to try and counter the Allied numerical superiority. The Raupenschlepper Ost (RSO) was no exception to the armed conversions that were built upon so many German vehicles at the time.

The decision was made in 1943 to take the well proven battle tractor and place a Pak 40/4 on its back, in order to provide more mobile anti-tank capabilities on the front line. After only a very limited amount were produced, it was made clear that this was one conversion that was not a successful fighting vehicle.

The original Raupenschlepper Ost tractor/carrier with its trailer.
The original Raupenschlepper Ost tracked lorry with its trailer.

Origins in the mud

The development of this vehicle is directly linked to the development of the RSO tractor built by Steyr from 1942 to 1945. This tractor was developed to meet the needs of the Wehrmacht for bringing supplies and weapons to the front lines in the poor conditions that were met on the Eastern front. Many of the battles there were far from any road, and if roads did exist, they were often in very poor shape, especially in spring.
It was soon found that existing vehicles were not satisfactory for bringing supplies and the newer larger anti-tank weapons through this adverse terrain, thus the designs for the RSO were created. By 1945, about 27,000 RSO tractors had been produced.
German 7.5 cm PaK 40 anti-tank gun being towed by a RSO Raupenschlepper Ost (East) Tractor, Yugoslavia, Sep 1943
German 7.5cm PaK 40 anti-tank gun being towed by a RSO Raupenschlepper Ost Tractor, Yugoslavia, Sep 1943
Development of an armed version of the RSO began only a few months after the tractor was in service. It was found that, due the rough nature of cross country driving, the sights of a gun being towed behind an RSO would be knocked out of calibration. Due to this, experimentation was undergone with mounting several guns on the bed of the RSO, including 75 mm (2.95 in), 105 mm (4.13 in) and 150 mm (5.9 in) weapons.
The intent would be to unload the gun at the front with a collapsible crane. This would allow for quick transport of weapons, but would still require time for the unloading and set up of the gun, and did not allow for any firing of the weapon while still mounted on the tractor. Though a few trial vehicles were made during these tests, none entered mass production
In the summer of 1943, the need for gun mounted on an RSO that could fire without having to remove the gun from the chassis was seen. A version made with a low silhouette cab (with only lower body protection for the driver and co-driver), along with collapsible sides on the cargo deck, was designed to carry a 75 mm (2.95 in) Pak 40/4 gun that could traverse 360⁰. When Hitler was shown this design, he ordered that it be put on high priority for production, as he saw in it an excellent balance of mobility, firepower and economics, which would provide an excellent tank hunter to the front.
On October 1st 1943, a prototype was presented to Hitler, after which production plans to produce 400 a month was put in place, despite there being no combat trials yet. However, very few were ever made. It is unknown how many of this RSO variant were produced, but it is generally believed to be less than 100.
Some information exists showing that Steyr was designing a new prototype immediately after the first design was approved for production, under the name “PzJag K43”. This would be a new generation of RSO tank killer that would have mounted the larger Pak 43, as well as have a wider chassis with a more powerful and less noisy engine. However, all work was halted in late 1943, when Steyr was ordered to stop working on tracked vehicle designs.
 The sides of the Raupenschlepper Ost (caterpillar tractor east) SPG folded down to produce a larger platform for the crew of the 7.5cm Pak 40 gun.
The sides of the Raupenschlepper Ost (caterpillar tractor east) SPG folded down to produce a larger platform for the crew of the 7.5cm Pak 40 gun.

Use in combat

The first deployment of this vehicle was with Army Group Center in January 1944. Some were sent to the 1st Ski-jäger Brigade, and some were sent to Army Group North, to Armee-Pz. Jägerabteilungen 751 and 752. In the 1st Ski Jäger Brigade, the RSO with Pak 40 was incorporated into the 13th Panzerjäger-Flak company, where it was deployed in 2 platoons with an infantry escort platoon.
Inside an RSO Pak platoon there were 3 RSO Paks, 1 supply vehicle, a Kübelwagen for the platoon commander and a Kettenkrad. In action, this vehicle was said to be less than desirable. It was slow, noisy and the engine had a tendency to overheat in warm weather. The lack of armor and high silhouette was also an issue, as many crews were lost when they attracted fire of any kind.
The small fighting platform made it difficult to work in an effective manner, and the floor lockers for ammunition storage were difficult to open when the weapon was in use. The vehicle earned the nickname “Rollender Sarg Ost”, a play on the RSO abbreviation. This nickname translates to “rolling coffin east”, reflecting the thoughts of the soldiers who operated it.
This fully tracked, lightweight vehicle was conceived in response to the poor performance of wheeled and half-tracked vehicles in the mud and snow
The RSO SPG fully tracked, lightweight vehicle was conceived in response to the poor performance of wheeled and half-tracked vehicles in the mud and snow.

An article by Eric Matzner


Nuts and Bolts Vol. 9. 7,5cm PaK40/4 AUF. GEP Selbstfahrlafette Raupenschlepper Ost (RSO). Peter Kwok, Heiner F. Doske.
RSO article. Germany’s Raupenschlepper Ost 7.5cm PaK 40/4 auf. RSO. Rick Lawler 2011.
Achtung panzer article
Article. 2015.
Article. 2010
Surviving Raupenschlepper Ost list

Raupenschlepper Ost specifications

Dimensions (L W H) 4.17m x 1.7m x 2.49m (with canopy) (13’8″ x 5’7″ x 8’2″
Total weight, battle ready 5.2 tons (10,400 lbs)
Crew 4 (driver, commander, gunner, loader)
Propulsion Steyr V8 3.5l 8-cylinder, 85 hp
Suspension Leaf springs
Speed (road) 17 km/h (10.5 mph)
Range 250 km (155 mi)
Armament 75 mm (2.95 in) Pak 40/4 L/46, 28 rounds
Armor 5-10 mm (0.24-0.35 in)
Total production 80-90 in 1943-1944

Original Raupenschlepper Ost supply vehicle
The original Raupenschlepper Ost supply vehicle
Pak 40 auf Raupenschlepper Ost, vermicelli livery
Pak-40 auf Raupenschlepper-Ost, vermicelli livery
Pak 40 auf Raupenschlepper Ost, ambush camouflage, 1944
Pak 40 auf Raupenschlepper Ost, ambush camouflage, 1944.
Pak 40 auf Raupenschlepper Ost with its side panels panels down
Pak 40 auf Raupenschlepper Ost with its side panels panels down.



7.5cm Pak 40 auf Raupenschlepper Ost (RSO) with sides and canopy up
7.5cm Pak 40 auf Raupenschlepper Ost (RSO) with sides and canopy up
 Next Page Home Back Raupenschlepper Ost RSO 75mm PaK 40 German WW2 tank destroyer with canopy removed and sides down to increase the size of the fighting platform.
Raupenschlepper Ost RSO 75mm PaK 40 German WW2 tank destroyer with canopy removed and sides down to increase the size of the fighting platform.

Surviving vehicles

Raupenschlepper Ost RSO 75mm PaK 40 German WW2 tank destroyer
Raupenschlepper Ost RSO 75mm PaK 40 German WW2 tank destroyer at the German Tank museum in Munster.
RSO SPG at the German Tank Museum
Surviving RSO Pak 40 SPG at the German Panzermuseum in Munster without its canopy
Raupenschlepper Ost (RSO) 01 tracked lorry at the Auto + Technik Museum, Sinsheim, Germany
Raupenschlepper Ost (RSO) 01 tracked lorry at the Auto + Technik Museum, Sinsheim, Germany. Photo by Walter Schwabe.
Germans Tanks of ww2
Germans Tanks of ww2