The All Terrain Scout Transport (AT-ST), also known as thechicken walker for its two-legged design, was a bipedal walkerused by the Galactic Republic during the late Clone Wars and, later and more extensively, by the Galactic Empire during the Galactic Civil War. It was a successor of the AT-XT.
Colloquially known as a "chickenwalker" because of its shape and walking motion, the AT-ST was a light, heavily-armed, ground combat vehicle, and able to trek various environments. The stock model was equipped with a medium, chin-mounted, double blaster cannon, ablaster cannon on the port side, aconcussion grenade launcher on the starboard side of its head, two clawed feet, and was encased with 9095-T8511 grade durasteel.
The AT-ST was designed to be a recon, hit-and-run vehicle. It was lighter than its bigger brother, the AT-AT, and could withstand standard blaster fire, but was vulnerable to heavy laser fire and missiles, as well as physical attacks to the legs and the side of the head. The latter weakness was witnessed during the Battle of Endor, when the Ewok tribal warriors destroyed an AT-ST by using logs to ram the sides of the walker's head. The AT-ST could also be infiltrated by species with great physical strength. At Endor, theWookiee, Chewbacca, forced his way through the top hatch and took control of the walker in this manner.
The AT-ST's chin blasters had an effective range of two kilometersand were used for anti-vehicle attacks, while the armor-shieldedblaster cannon and grenade launcher provided close-range protection against infantry and light emplacements. Like the AT-AT, the AT-ST utilized a holographic targeting system, allowing a 360-degree view of its position. The armor was not sufficient to withstand blasts from starship cannons, but was impervious to small-arms fire.
The 8.6-meter-tall walkers were piloted by a crew of two Imperial Army pilots and carried 200 kilograms of cargo. The bipedal propulsion system was one of the primary weaknesses of the AT-ST. On even terrain, the walker could achieve over 90 kilometers per hour, but on uneven or shifting terrain, a walker could quickly become unbalanced enough to fall over.
An advanced gyro system, located beneath the command module, provided the balance needed, but could be easily damaged. Following the Battle of Hoth, Rebel tacticians learned to ambush and immobilize AT-ST's; once trapped, a well-placed rifle shot could destroy the walker's gyro system.
Two AT-STs and an AT-PT. The AT-STs have various modifications added.
The AT-ST was a highly modular walker design, being able to switch weapons slots and additional tools to fulfill a variety of roles on the battlefield.
Known modifications included a top-mounted, shielded gun turret for soldiers standing on lookout, mortars bolted to the upper side of the turret, side-mounted six-slot rocket launchers instead of laser cannons, and grenade launcher mounts on the walker's lower cheeks.
Non-lethal modifications included communications antennae, using additional armor plates to cover the battery packs and having a winch system underneath the chin gun. During the construction of the Imperial base on Endor, several AT-STs had their chin guns replaced with metal clamps and were used to tear down trees and make clearings for future construction.