Also known as the STRV 103 and the S-Tank, the 103 was a fascinating little dead end
in the history of tank design, or the final evolution of the WW2 assault gun, depending on how you looked at it. Stridsvagn is Swedish
for 'fight vehicle', or tank.
Produced by Bofors from 1959 until 1971, and used exclusively by the Swedish army until 1997, its claim to fame was that it had no turret - instead, the main gun ran along the length of the tank's body, with the three-man crew sitting on either side. The gun was aimed by turning the tank left and right, and could be elevated by raising and lowering the rear suspension, which was hydraulic. The tank itself was a green wedge - very much like the tanks from 'Battlezone' in fact, but flatter. The S-Tank's main advantage over other tanks was its inconspicuous silhouette - an inch under eight feet tall at its highest point. It was shorter than contemporary NATO tanks and Russia's T-72, although in the latter case not by much.
The S-Tank was powered by a turbine engine that provided locomation and a diesel engine that powered the hydraulic system. It had a British, NATO-standard 105mm rifled main gun, three FN MAG machine-guns, smoke and flare dispensers, and, like the Israeli Merkava, was built for crew survival, with the engines being in front of the crew (as with Israel, Sweden's population is not large enough for their military to waste soldiers). The tank could be operated solely by either the gunner or the commander, as the main gun was self-loading and driving yokes were duplicated between stations.
Whilst a very clever concept, the tank had some major disadvantages which led to its replacement in the 1990s. Firstly, it was impossible for the tank to fire whilst on the move, and furthermore there was no way of engaging targets which had moved to the rear of the tank. The twin-engine design added complexity, and the hydraulic system was prone to breakages - as with WW2 German assault guns it was useless when immobile. The compact design, with an autoloader, meant that it was hard to upgrade the 105mm gun. More importantly, although the tank was hard to spot, the armour was simply not thick enough to protect the crew once discovered and engaged.
Nonetheless, the S-Tank is one of the most recognisable pieces of cold war military hardware, and along with the Chieftain and M60A2, one of the most attractive. Early fans of the Sinclair Spectrum might also recognise the S-Tank from the cover of Imagine Software's 'Stonkers'.