In the Spring of the year in which the Thai-Burma Railway opened to traffic, from about the time when the order for rush-construction was received, the strain of the war situation was becoming intense. The year before, the America Navy, who began their counter-offensive after the start of the war, in June 1942 in the action off Midway Island sank most of the Japanese Navy's aircraft-carriers, inflicting a heavy loss on us. This naval battle complicated things for us and the Japanese Army, with the now enlarged Pacific battle-line, ran risks in their lines of communication. Our Army assaulted the Australian perimeter but their attacks collapsed after hard fighting at various points. In the SE Asia war theatre our Army's dispositioning of fighter aircraft proved to be inadequate.

For the Burma Expeditionary Force in their assault on India, after capturing Burma, the supply-line was to be the construction of the Thai-Burma Railway, of which the opening-to-traffic coincided with enemy air raids which damaged their carrying-power of this supply route.

In the circumstances with a number of Allied Forces’ prisonersof-war employed on it, from the time when construction started it looked as if detailed intelligence information was being reported from the prisoners. From early 1943 recce aircraft frequently flew over. In June 1944 there was damage to tools and materials accumulated at the base at Thanbyusayat, and concurrently the prisoners’ quarters were bombed. The base on Thai-side at Nong Pladuk was also raided and prisoners-of-war injured. To avoid injury to their own men as prisoners, the enemy appear to have made surveys of the locations of camps.* From the Japanese angle, enemy attacks were to be expected but, having no fighter-planes, our AA arrangements were inefficient, yet despite it all we had opened the railway to traffic. In May 1943 the Mae Khlaung steel bridge was completed. AA-gun posts were set up and they gave partial protection to the bridge itself.

The enemy's attacks had effectively started with the opening to traffic of the railway. Obviously, to hinder rail transport, to collapse railway bridges was the most effective stratagem. They began with the steel railway bridge over the Mae Khlaung and went on to the very large number remaining of small wooden bridges.