To carry out the I Corps operational order, General Seiden put the division’s own AMAZON plan into effect on 1 July. On this date Companies A, B, and D of Lieutenant Colonel Harry D. Clarke’s 1st Engineer Battalion began extensive preparations for debris removal from the four bridge sites in the division sector. Even before this, Marine engineers and shore party personnel had been trained at special schools to handle U.S. Army equipment provided for the AMAZON operation.[156]
[156] This included employment of the 60-inch searchlight for night illumination, maintenance of boats for debris removal, and operation of the M-4 ferry. Other preparations by the division, of a non-engineer nature, included positioning of 13,000 life-saving floatation devices for use by frontline troops should they become shut off from planned evacuation.
Beginning 1 June, division engineers began blasting away at objects that flood waters could loosen and carry into the bridge supports. Bridge approaches were improved and their supports strengthened. Each company had a detail living at the bridge site for which it was responsible. With the advent of heavy rains, these Marines were to operate 24-hour boat patrols to keep the river free of debris. The engineers were also to maintain a round-the-clock debris watch at the four division bridges—Freedom Gate, or the Munsan-ni Railroad Bridge in the left regimental sector; Honker and X-Ray in the center; and finally, Widgeon, very close to the Commonwealth boundary.
Heavy rains began on 27 July and continued until the 30th. On the first day the decking of Widgeon Bridge was completely submerged and Honker was removed to prevent its being carried away. Precipitation increased on 28 July and reached its peak on 29 July when 3.66 inches of rainfall were recorded. By the 30th, the rains had subsided but not before the overflowing Imjin had collapsed the X-Ray bridge. During the height of the four flood days, engineers fought the rains, flooding waters, and floating debris. The major effort took place downstream to save the Freedom Gate Bridge.
Assigned personnel removed debris from the bridge supports, guided large, dangerous pieces away with poles, while upriver the boat teams blasted still larger sections into manageable chunks that would pass between the bridge supports. These engineer efforts, in addition to regular repair and maintenance of the large road net, constituted the major ground activity in the 1st Marine Division sector in late July. August would bring more rains and emergency demands on the engineers, but the critical ground activity at that time would be directed against the Communists in the area around Bunker Hill.
CHAPTER III
The Battle of Bunker Hill
The Participants and the Battlefield—Preliminary Action on Siberia—The Attack on Bunker Hill—Consolidating the Defense of Bunker Hill—Company B Returns to Bunker Hill—Supporting Arms at Bunker Hill—In Retrospect
The Participants and the Battlefield[157]
[157] Unless otherwise noted, the material in this section is derived from: PacFlt EvalRpt No. 5, Chap. 8; 1stMarDiv ComdDs, Jul-Aug 52; 1stMar, 2/1, 3/1 ComdDs, Aug 52; 1st MAW ComdD, Aug 52.