Rail-Class Advanced Recon Commando

The Rail-class Advanced Recon Commando was a Post-Republic generation of ARC troopers that was secretly bred by the Kaminoan scientists in a plot to liberate Kamino from the rule of the Galactic Empire. Unlike the clone troopers that served in the Clone Wars before becoming Imperial stormtroopers, the Rail-class ARC troopers were trained to have absolute loyalty to their Kaminoan creators instead of Emperor Palpatine. Created to compliment Kamino's army of Anti-Imperial clone troopers as an elite force, the ARCs were stationed within the Tipoca City Cloning Facility to protect the Kaminoans' precious batches of young clones that were still being developed to fight the Empire. When the Empire learned of Kamino's plans for insurrection, the Sith Lord Darth Vader dispatched a special detachment of the 501st Legion, under the command of the bounty hunter Boba Fett, to Kamino with orders to annihilate the entire army of rebel clones. Thus, the Rail-class ARC troopers made their first and last stand alongside the Anti-troopers at the Battle of Kamino in the year 12 BBY.

Kamino's Secret Clone Army
"So Palpatine has a new army. I have no doubt he'll find our cloning operations a threat one day very soon, and seek to destroy our capabilities. But he's a fool if he believes we handed over all of the combat-trained Fett clones to him." ―Lama Su, Kaminoan prime minister, on discovering Palpatine's new Imperial Army. Following the rise of the Sith Lord Darth Sidious as Emperor of the Galaxy, he quickly consolidated his Galactic Empire with an iron fist. Paving the way for Imperial rule were the Imperial stormtroopers, clones of the late bounty hunter Jango Fett that served as the Galactic Republic's clone troopers prior to the Emperor's ascendancy to absolute power. It was then that the Kaminoans found their homeworld placed under Imperial occupation by their own creations, no less. Having made the mistake of indoctrinating the original Fett clones with absolute loyalty to the Republic, and thus the Empire, the Kaminoans sought to rectify their error by discreetly breeding a new clone army that was completely obdeient to their Kaminoan creators. While the majority of the army was composed of Anti-troopers, a special force of elite soldiers were created to compliment the regular soldiers. Hence, the Kaminoans engineered a new generation of Advanced Recon Commandos—the Rail-class ARC troopers. Under the observation of the Kaminoans, the Rail-class ARCs and the rest of the rebel clones were grown and trained for nearly a decade.

The Rail-class ARC troopers were equipped with the ARC-variant Phase I armor, which included the command pauldrons and kamas. Their primary weapon was the chainguns.

The Uprising of Kamino
Approximately twenty years after the Kaminoans created the first clone army for the Republic, the Sith Lord Darth Vader sent the 501st Legion to destroy the rebel clones and bring Kamino back into line. The 501st's mission commander was the bounty hunter Boba Fett, who also happened to be a clone of Jango Fett. While the Anti-troopers defended Tipoca City's outer perimeter, the Rail-class ARC troopers remained within the cloning facility to protect the batches of undeveloped rebel clones. Despite their fast growth and training, the Anti-troopers proved to be no match against Fett and the battle-hardened stormtroopers of the 501st Legion, many of whom were veterans of the Clone Wars. After storming the facility, Fett and his stormtroopers were suddenly engaged by the Rail-class ARC troopers, some of whom tried to take the fight outside and prevent the Imperials from breaching the Tipoca City. Their efforts failed, however, and the life support systems were destroyed, thus aborting the unborn Anti-troopers before they had a chance to fight. With the rebel Kaminoans' capabilities to defend the city or grow another clone army severely diminished, they opted to escape from Kamino before the battle was completely lost.

In the meantime, the last of the Rail-class ARC troopers joined the remaining Anti-troopers as they desperately fought against their relentless Imperial clone brethren. Though they fought on, Fett and the 501st stormtroopers succeeded in crowding the rebel clones out onto the platforms where they were exterminated to the last clone. With the death of the Kaminoan insurgents that bred the rebel clone army, the Rail-class ARC troopers perished along with the Anti-troopers and the "clone rebellion" not only ended in failure, but would never be publicly known since all information regarding the Kamino Uprising became highly classified.The Rail class-ARC Trooper could kill 3 Imperial Stormtrooper's in a 2 second ratio.