The Swedish strv 103 (tank 103) or "S"-tank


Sigurd Helge's info.

Here is some info which you may use as you see fit, none of the info is classified and it is all 100% true. My reference material is the original instruction book for troops (how to use and maintenance), and two books from our national armour club "SPHF": Svensk Pansar Historisk Förening (the Swedish Armour Society) and of course I have added some personal but nonetheless genuine thoughts and experiences.

The Swedish strv 103 (tank 103) or "S"-tank.

In the beginning of the 1950's Sweden carried out some extensive AFV trials and developments. In 1953 Sweden was able to purchase 80 Centurions (strv 81 or "tank 81") from Great Britain and therefore the development work temporarily stopped, at least concerning the tank trials. Later on Sweden purchased additional Centurions to form the entire national tank fleet. However during the late 50's Sweden decided to pick up the trials where they had left them. Due to very thorough investigations and reports about recent conflicts (the main source of course being WW2) Sweden drew its own conclusions about how a future tank concept would look like. The main idea was to reduce the tanks frontal silhouette to a minimum and to give the crew maximum protection. According to hit probability analysis that Swedish engineers did, the hit probability increased with increased height of the vehicle and that it was 100% higher/ square inch in the turret than in the hull. So the solution was get rid of the turret! Several initial trial vehicles were built, amongst others a WW2 Sherman (bought from France after the war) which featured a fixed gun and a rebuilt running gear, this prototype was used to test aiming and gun traversing using only the tracks.

The result of these trials resulted in a very complicated hydraulic suspension system wich also incorporated the elevation and traverse of the main gun.

In 1959 "Bofors" (the well known Swedish ordnance manufacturer) got the order to build two main prototypes (S1 and S2) to "stridsvagn S" as it was called, S standing for Swedish. The prototypes were delivered in 1961 and later on 10 additional test vehicles (the "0" series) were delivered. In 1964 the Swedish government decided to purchase 290 tanks, the first in the series were delivered in 1967 and the last were delivered in 1971. The tank underwent two major rebuilds, the first in the middle of the seventies (strv 103B) and the second in the middle of the eighties (strv 103C). The "C" conversion added german Diehl tracks, laser range detector, new engines and additional protection, the most visible change being the "jerry can" rack on the sides.

Its main advantage was always the excellent 105 mm (though rifled) gun. The latest ammunition to be used had penetration nearly as good as contemporary 120 mm smoothbore guns. Another good feature was that both driver/gunner and the commander could both fire and drive the tank. In effect, if the reverse driver and the gunner/driver were put out of action the commander could still both "shoot´n scoot"!

The bad features was that it was supposed to have good protection. And with the engines and transmission in front of the crew thus serving as additional armour it also had, at least in the 60's when it came. But when the T-72 arrived it became apparent that the protection needed to be improved. A steel "fence" was added to the front armour wich had some effect but when the T-80 appeared it was apparent that the protection was inadequate, to say the least!

In fact during the beginning of the 90's Sweden managed to get hold of some T-72's. The armour development section made some live firing tests against the "S" with them and the results were horrifying. Most of the rounds penetrated the frontal armour (through the steel "fence") smashed their way through the engines and crew compartement and ended their days in the ammunition stowage compartment, in the rear of the tank. NOT a very comforting surprise.

Another main disadvantage was that you couldn´t fire with any precision on the move! And with a fixed gun you couldn´t aim your gun at the most dangerous direction while on the move. Crucial, basic needs for any modern tank.

To add on the list of disadvantages the giant hydraulic system was both hazardous and posed a very serious firethreat. It was also prone to breaking down. The MTBF was appallingly short... (Mean Time Between Failures).

Today the "S" tank is no longer in service, the last conscripts to get training did so in 1996. It was decided to scrap the tanks but only when Sweden had aquired enough new tanks.This happened in the end of the 90's when Sweden purchased Leopard 2 A4 and A5 (the "Improved"). Recently the scrapping began and now (Jan 2000) the trains, loaded with tanks, are steadily rolling to the blast-furnaces.


Combat weight: 42,5 metric tons

Length: 8.99 metres

Width: 3,63 metres

Height: 2,14 metres ( turret roof)

Crew: 3 , one commander, one driver/gunner and one "reverse driver" facing backwards, behind the driver/gunner.

Ground preassure: 104 kPa

Power/ weight ratio:18,4 hp/ ton

Max speed: 50 km/ hour

1 x Detroit diesel (6V-53T) mainly used to produce power for the hydraulic system.
1 x Caterpillar diesel gas turbine engine for the propulsion of the tank.
Total hp: 780 (the piston diesel: 290 hp and the gas turbine 490 hp)

Transmission: Volvo and Bofors, 3 automatic gears. The reverse utilizes the forward gears also so it as fast in reverse as in forward gear.

Hydraulics: contains 140 litres of HIGHLY flammable and VERY toxic hydraulic oil........

1 x 105 mm main gun (the license built British L7 gun)
2 x fixed ksp 58 (the swedish licensebuilt MAG) in the hull.
1 x ksp 58 by the commander (wich he can aim and fire independently from his seat)
2 x 71 mm flaremortars ("lyran"), the "S" had no thermal imaging sights or other modern observation devices.
8 x close proximity smoke dischargers fixed on the commanders cupola.
(The commanders observation cupola was hydraulically powered and he could elevate and traverse it and fire the smoke and machinegun in any direction he saw fit.)

105 mmAPFSDS
105 mm HE
105 mm smokerounds for the main gun (a separate magazine manhandled by the reverse driver containing 5 rounds)

The main gun used an autoloader (located in the rear) containing up to 50 rounds . This worked very well and had loading times of about 3 seconds. To change ammunition you simply pressed a button. You could also fire in "automatic" mode (when for example you wanted to fire for effect with HE rounds). Thereby the system "locked" the elevation system giving it quite good precision. 1500 7,62 rounds for the machineguns (500 in each magazine).

"Trial S1 or S2":This is one of the two trial vehichles (S1 or S2) built in 1961. It has a lot of features wich are found on the final design, though it has several features that doesn´t. For example no floating bellows and it lacks return rollers. This prototype weighed 34 metric tons. This actual vehicle now resides as a monument outside the Southern Skåne brigade training grounds in the southern part of Sweden.
10114 pic

Download the big pics by clicking on the small pics...

"O series": This is one of the ten "0" series vehichles. Most of them were rebuilt into the final design but a few were spared and now they stand as monuments, this one at the Ravlunda live firing grounds in the southern part of Sweden.
10115 pic

Download the big pics by clicking on the small pics...

"S tank winter": This picture is taken at the Tåme live firing grounds in the northern part of Sweden in 1991. This is the strv 103C version, though without the "jerry can" racks and "steel fence". The fixed double machineguns are located in the (from the viewers point) right frontal armour "box" (barely visible).
10116 pic

Download the big pics by clicking on the small pics...

"Strv 103C": This is a picture taken at the "Army annual day" in 1992. The location is Gärdet in central Stockholm. In this picture you can see both the "jerry can" rack and the steel fence. The steel fence was until this day a secret and would only be attached in case war broke out. In 1992 it was decided that the "fence" was obsolete and therefore it was officially disclosed.
10117 pic

Download the big pics by clicking on the small pics...

"103 scrapyard":Photo taken in November 1999, it depicts part of the 60 tanks previously stationed in the northern part of Sweden. They are lined up for railway transport, destined for their final resting place...
10118 pic

Download the big pics by clicking on the small pics...


Doug's comment:
In it's day, the "S" tank was a revolutionary concept and considered a novelty in the tank world. Considering it's time in service spanned from the mid 60's to the end of the 90's (but with a realistic battle life which was probably over by the mid 80's) the Swedes did remarkably well for a country of their size and resources.
I got to see an "S" tank at both Bovington in England and Munster in Germany; the one thing that photo's do not convey is the size of the vehicle. In all the published photo's I have seen of "S" tanks there are no people visible to add scale or they are too far away from the vehicle. When you see one of these vehicles in real life, although they look squat, they are still impressively big. The other thing that really stands out is the acute angle of the glacis plate, which is probably the ultimate example of sloped armour.

My thanks to Sigurd for the text.


  sig - logo