All Terrain Armored Cargo Transport The All Terrain Armored Cargo Transport ( AT - ACT ) was a larger version of the standard All Terrain Armored Transport combat walker that featured a dedicated cargo bed for the transportation of heavy building materials or combat munitions . Description . The All Terrain Armored Cargo Transport was deployed at major Imperial construction projects , such as shipyard s and sprawling research installations . Although the AT - ACT was not built for combat it was still capable of posing a formidable threat to infantry as discovered by Rebel trooper s during the Battle of Scarif . The walker ' s taller profile gave it a faster stride than an AT - AT , although at the expense of structural stability . To give the knee joints extra strength when carrying cumbersome loads , an electromagnetic tensor field kept the overstressed motive assembly in smooth alignment . The cargo module housed within the AT - ACT ' s frame encompassed nearly 550 cubic meter s of space and was capable of carrying raw material . Loads were carefully managed by stevedore droid s who divided up partial holds of ultradense materials into manageable trips . Powerful engine s and tensor field - supported legs kept the massive AT - ACTs moving forward , from mining sites to processing facilites , carrying cargo in situations where repulsorfield s were unreliable or not suitable due to material incompatibilities . Despite the existence of AT - ACT driver s , the AT - ACT ' s design did not boast a specialized driver corps , as it was not technically designated a battlefield assault vehicle . Imperial combat assault tank pilot s , AT - AT pilot s , and other imperial combat driver s in the Imperial Military were all qualified to operate it . History . At least four AT - ACTs were present on Scarif in a battle against a squad of Rebel soldiers . When the Rebel incursion threatened the security of the Imperial security complex , Director Orson Krennic ordered the beach secured , and the ground crews seized this initiative to move their AT - ACTs into action . They proved resistant to the weapons of the Rebel troops , but took losses when faced with X - Wings and U - Wings . They , along with all the other Imperial and Rebel forces in the area , were destroyed when Wilhuff Tarkin ordered the Death Star to fire on Scarif . After the Battle of Endor , the walkers were among the forces deployed to defend Kuat Drive Yards during the New Republic ' s siege against the shipyard s . At least one walker was stationed on the Mid Rim planet of Kashyyyk in the Black Forest before its liberation by the New Republic . By two years after the Battle of Jakku , the walker had fallen was covered in fern and flower s , with plant stalks and small tree s sprouting from its blown - open metal belly . Behind the scenes . The first footage of the AT - ACT was shown in the " " teaser trailer on April 7 , 2016 . The walker was identified as AT - ACT in a preview of the canceled reference book " Rogue One : A Star Wars Story : The Official Visual Story Guide " on May 17 , 2016 . The full name was first revealed in the third episode of " The Star Wars Show " on May 25 , 2016 .