Commanded by Lieutenant Colonel Dobervich, the 1st Amphibian Tractor Battalion (minus Company A at KPR, and Company B at Pohang), reinforced by the Division Reconnaissance Company, had manned positions on the KANSAS line since April 1952. By the end of May, the battalion had inserted an additional unit, a provisional company,[335] in the KANSAS secondary defense line. In July, the amtrac company relieved the reconnaissance company on line, the latter then becoming part of Headquarters Battalion, 1st Marine Division. All amphibian tractor battalion units assigned to ground defense missions received special refresher training in infantry operations, including the employment of forward observers. [335] Comprising a platoon from Company B and several headquarters elements, the provisional company was disbanded on 14 June when Company B that had been supporting MAG-33 at Pohang was reassigned to the battalion. During the first summer in the west, the mainland-based amphibian organization continued its KANSAS defense mission. The battalion also instituted a training program for patrolling the Han River by tractor. (Company A, attached to the KPR, had conducted waterborne patrols of the Yom since June. The unit also manned outposts along that river.) Headquarters and Service Company assisted the U.S. Army in laying a signal cable across the river during August, the same month Lieutenant Colonel Dobervich relinquished unit command to Lieutenant Colonel Edwin B. Wheeler. In late August the battalion sent 58 of its members to help augment 1st Marines ranks, thinned by the fierce Bunker Hill fighting. Through the end of 1952, the 1st Amphibian Tractor Battalion continued its KANSAS mission. Although the sector had witnessed relatively little action for some months, several incidents about this time varied the generally quiet daily routine. In October, Company B (Major Charles W. Fitzmaurice) sent out an amphibious patrol to capture prisoners (Operation CAT WHISKER). The plan was to cross the Han in a rubber boat and set up an ambush after reaching the enemy shore, but a storm-angered river, with a strong tide boosted by heavy winds, prevented landing of the boat. Two months later, another snare--this one set by the enemy--was partially successful. Several hours after dark on 1 December, the jeep assigned to the battalion commander, Major George S. Saussy, Jr.,[336] was being driven on the MSR by Private First Class Billy J. Webb, its operator and only occupant. [336] Formerly the executive officer, Major Saussy took over unit command on 7 November, when Lieutenant Colonel Wheeler was transferred to the 5th Marines. Lieutenant Colonel Frank R. Wilkinson, Jr., became the next commanding officer on 16 March 1953.