T
It was discovered, to none's surprise, that the Abrams could not handle the rocky terrain and had to have its combat speed reduced to avoid injuries to the crew and excess fatigue.
The Abrams' torsion bar suspension does not provide the same dampening capabilities that spring suspension (Merkava) or hydropneumatic (Leclerc, Challenger 2, K2) provide.
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The Merkava uses a spring suspension that is mounted externally and thus far easier to repair and provides excellent side protection and IED protection, whereas the Abrams uses torsion bar suspension, which is less efficient over harsh terrain and against mines/IEDs, but is lighter.
IIRC, the Merkava I drive train and suspension was largely inspired by the British Centurion and the tracks were directly derived from it. Mk3 has upgrades to the drivetrain, powertrain, armament, and electronic systems. Mk 3D
Dor-Dalet has upgraded and strengthened tracks (built by Caterpillar, designed in Israel). Mk 4 has the Israeli-designed "TSAWS (
Tracks,
Springs,
and
Wheels
System)" caterpillar track system, called "
Mazkom" by troops, designed to reduce track-shedding under the harsh basalt rock conditions of Lebanon and the Golan Heights.
Torsion bar suspensions are used on combat vehicles or tanks like the T-72, Leopard 1, Leopard 2, Chinese MBT-3000 and the M1 Abrams. The main advantages of a torsion bar suspension are durability, easy adjustability of ride height, and small profile along the width of the vehicle. It takes up less of the vehicle's interior volume than coil springs. A disadvantage is that torsion bars, unlike coil springs, usually cannot provide a progressive spring rate. In most torsion bar systems, ride height (and therefore many handling features) may be changed by simply adjusting bolts that connect the torsion bars to the steering knuckles. Due to their small size, tremendous load capacity, and relative ease of service, torsion bar suspension has been ideal for tanks, though it is not without disadvantage. The large travel and high elasticity of the torsion bars results in a "rocking" motion when the tank is moving or coming to a sudden stop. Due to the massive weight of a main battle tank, there is a much greater risk of breaking a torsion bar on sudden bumps or maneuvers, and if it is not replaced in short order the reduced suspension can affect the maneuverability of the vehicle, and in extreme cases risk immobilizing the vehicle as the reduced capacity of the suspension causes additional torsion bars to break.
