Developed in the 1950s, then modernised in the 1980s, the Stridsvagn 103 S-Tank is the first main battle tank to use a turbine engine and to dispense with a turret. This unconventional design has a unique gun laying process: its fixed gun is 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.