Two were used during the Battle of Crait to drag over a superlaser siege cannon towards the Resistance base. Although their primary purpose was to tug massive ground weapons, they were far from defenseless: the actual cables used to tug the superlaser were composed of 27,252 steelton wires, and aside from their impressive defenses of a medium fire-linked dual laser cannon on each corner of the mech as well as matrixed composite armor comparable to the All Terrain MegaCaliber Six, they were also backed up by a compliment of escorts ranging from AT-M6s, AT-ATs, TIE Fighters, to even patrolling snowtroopers.
AT-HHs were designed to complete the unique job of pulling massive loads across the battlefield. Their unusual multiple-legged design, comparable to crustaceans and insects, provided immense power while giving the insurance of still being able to move if one or more legs were damaged.
The walker had 3 rows of rotatable and repositionable legs; with the front consisting of 11, while the middle and rear rows had 10 each. Redundant legs were included to serve as a back up, once the primary legs had failed. Each leg was suspended from a sturdy dowel structure and made with heavy-duty hinge joints and refined durasteel bearings. They were powered by a main piston actuator, combined with heavy "knuckle" actuators and hydraulic "tendon" pistons. This design proved highly successful, with the tug walkers being able to complete their objectives with more than 40% of their limbs inoperative during field tests on Dromodar Beta.
The flat top deck of an AT-HH was covered in thick armor plates and each corner had its own medium fire-linked dual laser cannon (four in total). The turrets were controlled from the two engineering and gunnery stations located on both the starboard and port areas of the walker. The bridge is located on the front of the deck offset towards the starboard side by the primary sensor node hub. It is here that the pilot, commander and co-pilot are stationed in a configuration comparable to an AT-AT.
In battle AT-HHs used a combination of escorts and its own defences for protection. Each strand in its tow cables used to connect the walker to its load were made up of a bundle of 27,572 steelton wires, meaning they easily withstand laser cannon fire. They can be used to haul anything from disabled warships to prefabricated base modules and are powered by its on board fusion reactor.
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