Stridsvagn 103

The Stridsvagn 103 (Strv 103), also known as the Alternative S and S-tank, is a Swedish Cold War-era main battle tank, designed and manufactured in Sweden. "Strv" is the Swedish military abbreviation of stridsvagn, Swedish for tank (literally combat wagon, it also is the Swedish word for chariot), while the 103 comes from being the third tank in Swedish service to be equipped with a 10.5 cm gun.

Developed in the 1950s, it was the first main battle tank to use a gas turbine engine and the only mass-produced tank since World War II to not use a turret besides the German Kanonenjagdpanzer, which is not classified as a tank by role, but by design. It has an unconventional design with a unique gun laying process: it is turretless with a fixed gun traversed by engaging the tracks and elevated by adjusting the hull suspension. The result was a very low-profile design with an emphasis on survivability and heightened crew protection level.