As a result of an I Corps directive, the 1st Marine Division assumed responsibility for an additional 6,800 yards of front on 14 April from the 1st Commonwealth Division sector to the right of the division. In preparation, the 5th Marines had taken over the western end of the 1st Marines sector, held by 2/1, two days earlier. On the 14th the 1st Marines, newly commanded by Colonel Walter N. Flournoy,[50] extended its line eastward to assume new limiting points and part of the MLR in the western part of the Canadian Brigade sector. Relief of the Commonwealth unit was completed without any difficulty or enemy interference. This additional yardage, plus the Kimpo Peninsula front, now stretched the Marine division MLR to 35½ miles. [50] Colonel Flournoy became regimental CO on 10 April, succeeding Colonel Wade. As a result, General Selden found it necessary to withdraw the division general outpost line in order to build up his main line of resistance. On 17 April, the 1st KMC Regiment reduced its OPLR to an OPLO (outpost line of observation) and the left battalion pulled its MLR back to more defensible ground. The Marine division center and right regiments withdrew their outpost lines on 23 and 24 April. Both regiments then established forward outposts and listening posts which, in many cases, utilized former OPLR positions. Many of these posts were manned during daylight hours only. Abandonment of the forward OPLR added strength to the main line, but it also meant that frontline battalions had to commit all their companies on line, thus losing their reserve. To prevent Chinese occupation of desirable terrain features on the former OPLR, the division dispatched combat and reconnaissance patrols forward of its line. In the KMC sector, the only Marine area favorable for tank operations forward of JAMESTOWN, tank-infantry patrols were periodically employed. To the west of the KMC sector, the Marine 1st Amphibian Tractor Battalion (Lieutenant Colonel Michiel Dobervich) was assigned a section of the KANSAS Line to defend, beginning 16 April. Reinforced by attachment of the Division Reconnaissance Company (Major Ephraim Kirby-Smith) that same day, Lieutenant Colonel Dobervich employed Company C (two platoons), the headquarters LVT platoon, and the reconnaissance unit to man 30 defensive positions from the Han River eastward to the KMC western boundary.[51] [51] Company A, 1st Amphibian Tractor Battalion had been attached to the Kimpo Provisional Regiment since 31 March and Company B was supporting MAG-33 at Pohang.