SP42 Cobra

The Special Purpose-42 Cobra mobile gun system (SP42 Cobra MGS), later designated as the M845, is a wheeled armoured fighting vehicle formally used by the CMA and later the UNSC. The SP42 was originally manufactured by TurboGen, and was later maintained by Misriah Armory.

History
The Colonial Military Authority put out a design competition at the height of the UNSC-CMA Cold War for a fast, light weight mobile gun system capable of ambushing and killing the then newly introduced UNSC M840 main battle tank, with a contract being awarded to TurboGen's TG-8, adopted as the SP42 Cobra MGS by the CMA. This bid was deeply suspicious; while the other competitors had undergone quite a substantial period of testing, the TG-8 was adopted shortly after being submitted. Allegations of corruption and bribery were made to the CMA Procurement Board, but these concerns were quietly ignored. A report citing that the TG-8's transforming nature and its ability to easily penetrate the armour of last-generation tanks as making it superior to all other alternatives. This is where the problems would begin.

As a testament to the SP42's unconventional design, TurboGen missed multiple scheduled delivery dates, citing that its complexity made it very difficult to tool up for. The CMA would receive their first shipment of forty Cobras in March 2495, but many of these were secretly diverted by sympathizers to Secessionist Union elements, among them Colonel Robert Watts' forces on Eridanus II. In a bit of irony, the first time Cobras saw combat would be against the UNSC during Operation: CHARLEMAGNE in 2497 - to the horror of Watts' forces. As it turned out, the severe quality control and lack of design maturity behind these vehicles would come to the forefront. There were reports of Cobras breaking down and stopping after only taking minor damage, railguns failing to fire after being charged, and most importantly, jamming up while transforming between their static and mobile forms, rendering them completely useless in combat.

The CMA would not deploy the Cobra into combat for the better part of a decade, and instead focused its efforts on rectifying its problems. TurboGen's incompetence would eventually see them taken off the Cobra program, and instead Misriah Armory would be begrudgingly hired in their place. After the CMA Army shot down multiple proposals to cut the transforming functionality from the design, Misriah's engineers effectively rebuilt the vehicle inside and out. It was formally reintroduced back into service by 2509, however, the stink of its first incarnation continued to make it extremely unpopular with soldiers.

Following the absorption of the CMA by the UNSC, the Cobra's place among their armoured forces was questionable. They were of questionable value as the UNSC had little use for specialized anti-armor vehicles and were looking to move away from rail gun technology. With encouragement, Misriah Armory experimented with different armaments for the now reclassified M845 Cobra.

The Cobra found value during the Covenant War, as its railguns were highly efficient in penetrating Covenant armor, more so than the UNSC's homemade main battle tanks. After the war however, the Cobra fleet was severely aged, as its railguns were already antiquated even before the war had begun. Humanity's rebuilding efforts however prolonged its retirement until after Operation: RUPTURED CRUCIBLE.

Design
Despite its light armor and wheeled design, the Cobra's speed still lags far behind its UNSC contemporaries owing to its cheap and inefficient powerplant. This lackluster powerplant further hinders the speed in which it can charge and fire its powered rail gun. The SP42's abundance of problems baffled Misriah Armory engineers when they were contracted to produce it, and required years of technical overhauls before it could be fielded.

Misriah Armories replaced the Cobra's RGS series rail guns with its own M66/M98 models, as well as its power pack. These changes solved a majority of the Cobra's issues, however it still hadn't solved the lack of purpose it had within the UNSC's arsenal. Limited run variants were produced based on the Cobra chassis in an early attempt to give the Cobra a place within the vehicle fleet. During the Human-Covenant War, the Cobra received armor upgrades as it was susceptible to even light plasma cannons.

M846
A self-propelled gun with an autoloaded 155mm/55 howitzer. The M846 is a vital asset of the Marine Corps because of its air mobile capability.

M847
A Cobra mounting the M260 Multiple Launch Rocket System from the M9 Wolverine SPAD, used exclusively by the UNSC Army.