Demolition charges were used effectively by patrols for the destruction of enemy ammunition dumps in inaccessible locations and not salvageable because of the tactical situation. Except for this purpose, demolitions were not extensively used.[13]
The 37-mm. gun was an antitank weapon only occasionally employed by the 7th Division because there were few Japanese armored vehicles against which to use it. The excessive difficulty of manhandling it into a position from which fire could be delivered against Japanese pillboxes and machine guns rendered it ineffective for that purpose. The 90-mm. guns of the antiaircraft artillery had a considerable number of erratic bursts because of corroded fuzes and worn fuze setting lugs.
The tanks and tank destroyers could have been used more frequently and with greater versatility. Situations often arose in which an infantry platoon was held up by enemy machine gun and mortar fire, but “the use of indirect artillery fire was impracticable either because of overhead cover for the enemy weapons or because of undue risk to our enveloping infantry.” General Krueger recommended that the infantry employ direct fire by the tanks or tank destroyers. He felt that “the tank destroyer commanders lacked aggressiveness and skilled direction.”[14] The tank destroyer commanders admitted that they were idle but added that the infantry had not called for them. The tanks and tank destroyers were ideal weapons for the destruction of machine guns, mortars, and other heavy infantry weapons, but the infantry commanders seemed to be unaware of their capabilities. Many commanders employed their armored vehicles down the middle of the road when they could have used them more effectively on the flanks and for envelopments.
The 96th Division found the Cannon Company’s self-propelled 105-mm. howitzer extremely mobile in swamps and mountainous terrain. It was able to go several miles farther up the mountains than any other vehicle and gave excellent support in covering the mountain passes.[15]
The cargo carrier M29 (weasel) proved to be a most useful supply vehicle. The commanders used it for reconnaissance and visits to units in isolated areas and over roads that were impassable to wheeled vehicles. It also was employed to carry supplies and to evacuate the wounded from inaccessible areas. The weasel was much less destructive of roads than any of the other tracked vehicles, but the tendency to use it on dry roads resulted in worn-out tracks and excessive maintenance requirements.
The 96th Division found the DUKW to be an excellent vehicle when waterborne but on land, regardless of the condition of the roads and terrain, it was not half as effective as the 2½-ton cargo truck. On roads the DUKW was a traffic hazard and an obstacle to other cargo traffic.[16]
The 7th Division landed with seventeen one-ton trailers. They were found to be of little value and the division recommended that they should not be used in any future operation unless a hard-surfaced, all-weather road net existed at the anticipated target.[17]
Intelligence
General Krueger pointed out that prompt, aggressive reconnaissance should have been instituted immediately upon the landing of the troops. The fact that knowledge of the terrain was very limited before the assault—inaccuracies in the distances on existing maps were as high as 50 percent—gave urgency to the need for immediate reconnaissance.
The sources of information on the Japanese were as follows: ground and aerial reconnaissance, Filipino civilians, guerrillas, captured documents, and prisoners. Air observation was of limited value because of the Japanese ability at camouflage and because the inclement weather prevented aerial observation of many areas. The tendency of the Filipinos to say “yes” to everything was also a handicap. In general, the guerrilla reports were more accurate than those of civilians. Considerable information was obtained from patrols, which were especially valuable for on-the-spot intelligence.