An abandoned Cybercarrier survived one of the final battles of the Cyber-Wars intact and was later recovered by Ashad. It was stated to have the most advanced systems Yedlarmi had ever seen and could travel at an incredible rate of speed. (TV: Ascension of the Cybermen)
The carrier, carrying an army of hundreds of thousands of Cybermen and Cyberfighters, took part in one of the last battles of the Cyber-Wars, later identified by Ashad as the site of the Cybermen's greatest defeat. Despite the Cybermen suffering massive casualties, the carrier remained intact along with its army and was left drifting dormant at the battlefield. (TV: Ascension of the Cybermen)
Rekindling the Cyber-Empire
While trying to make it to Ko Sharmus and the Boundary in their Gravraft, Yasmin Khan, Graham O'Brien, Yedlarmi, Ravio and Bescot stumbled across the battlefield and the dormant Cybercarrier. With their ship all but completely disabled, the group managed to make their way into an open hanger bay on the carrier in order to salvage the ship and use it to reach the Planet of the Boundary. At the same time, Ashad arrived with two Cyberguards, guided by the Cyberium which was aware of the Cybercarrier's survival. Ashad intended to use the Cyber-Army still aboard the ship to rekindle the lost Cyber-Empire and quickly took control of the ship and awakened some of the Cybermen as it arrived at the planet. Though Bescot was killed, the remaining humans were able to hide in Cyberarmor and eventually escape.
Shortly after arriving at the Boundary, Ashad was contacted by the Spy Master who offered him Gallifrey. Ashad brought his carrier through the Boundary to Gallifrey and parked it above the Capitol. Intending to create a new race of CyberMasters, the Master was pleased to learn that the carrier's cyber conversion chambers were all operational, but betrayed and killed Ashad with the Tissue Compression Eliminator so that he could gain the Cyberium. Using the ship's chambers, the Master succeeded in creating his army.
Later, on the Doctor's orders, Yedlarmi, Ravio, Ethan and Ko Sharmus planted Ko Sharmus' explosives throughout the carrier which had not yet had its army fully awakened before Ashad was killed. Avoiding the Cybermen on board, the group escaped just in time before the explosives destroyed the Cybercarrier and the army aboard, foiling Ashad's plan to rekindle the Cyber-Empire. Ko Sharmus subsequently sacrificed himself to detonate the death particle to stop the Master and his army as blowing up the carrier wasn't enough to stop them. (TV: Ascension of the Cybermen, The Timeless Children)