SP42 Cobra

The SP42 Cobra, formally known as the Special Purpose-42 Main Battle Tank, is an anti-vehicle/anti-fortification vehicle used by the UNSC Marine Corps.

Background
Unlike many vehicles, the Cobra fills two distinct roles, that of a mobile anti-vehicle platform and that of a self-propelled artillery piece. Although it is not fast, the Cobra is still highly maneuverable, and can keep up with combat groups. Despite its heavy firepower, it has relatively poor armor.

The SP42 Cobra is equipped with a pair of M66 light rail guns on its turret that fire high-density ferrous slugs - which are twice the size of those used by the M68 Gauss cannon - designed to penetrate enemy armor using sheer kinetic energy. These weapons have a slow rate of fire. The rail guns fire intermittently, not in a single burst, as the energy required to accelerate the slugs to the speeds required to pierce the heaviest armor can only be managed for one of the cannons at a time. Synchronized fire from both railguns can destroy even the most heavily armored tank, with penetration that easily outguns the M808B Main Battle Tank's standard M512 90mm cannon.

In addition to the Cobra's anti-vehicle role, the vehicle can be stabilized upon the ground, "locking down", and deploy an arcing-trajectory M98 105mm light rail gun which fires a conventional explosive shells at supersonic velocities. The explosive and kinetic forces of the shell complement each other to increase the damage inflicted. An M98's shell, when specially outfitted, can penetrate a Type-30 Locust's energy shield and destroy the platform, while one shot can disable the shield upgraded Wraith's shield and deal minor damage.

However, the Cobra's use against groups of infantry is less effective if the infantry are spread apart, due to its small blast radius. Cobras can attack only ground units and are specifically designed to engage vehicles, so they are mostly vulnerable to Hunters and Banshees.

Upgrades

 * Deflection Plating: gives the Cobra extra protection. Cost 400 resources.


 * Piercing Shot: enables railgun to penetrate multiple targets, damaging each. Cost 900 resources.

Trivia

 * Like most UNSC vehicles, the Cobra is superficially similar to its animal namesake. When locked down, the Cobra lowers itself and becomes poised to fire; this is similar to actual cobras, which typically coil before striking. The SP42 is especially similar to the spitting cobra, which can project venom to great distances.
 * The Cobra's artillery mode has an uncanny resemblance to the Terran siege tank from Starcraft, which can transform from tank mode to siege mode, with a sacrifice of mobility for longer range and greater firepower.
 * The vehicle was originally described as being similar to a Russian 'Katyusha' rocket artillery vehicle, which was spurred on by the appearance of vehicles similar to the M9 Wolverine but possessing a different ordnance rack. This was a case of mistaken identity, as the vehicle sighted was actually a Wolverine, but with an upgrade adding a second missile pod, creating confusion.

List of appearances

 * Halo Wars