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The ARTILLERY BOMBARDMENT
Events thus far had not worked out as the Japanese had planned. The occupation of Manila had not given them the use of its fine harbor or the large military stores they had expected to find there. MacArthur had refused battle on the plains of Manila, and drawn his forces back into the Bataan peninsula intact. The occupation of Corregidor, which was next on the Japanese timetable, now had to be deferred for the lengthy and expensive campaign on Bataan. If the first air attacks against the island fortress had been intended as the prelude for a landing, they had been wasted.
To have attempted the investment of the Gibraltar of the East while the Bataan peninsula was in American hands would have been disastrous and foolhardy. The heights of the Mariveles Mountains dominated the small island only two miles offshore and were vital to its control. Even before the war the Japanese had recognized the intimate relationship between Bataan and Corregidor and in their prewar estimates had noted the lank protection Bataan offered to the island. "Mt. Mariveles in southern Bataan forms the left wall of the bay entrance," one Japanese estimate concluded, "and because it is covered with dense forests, use of siege guns and heavy equipment to attack this fortress is impossible."
The southern shore of Manila Bay offered only partial protection to the islands lying at the bay entrance. Here the ground was less mountainous and overgrown than on Bataan, and in the vicinity of Ternate, opposite the tip of Bataan, there were few obstacles to military movement. Into this area could be brought heavy equipment and siege guns. Once emplaced, these guns could bring the southernmost of the islands, Forts Frank and Drum, under assault. It was from here that the next attack against the harbor defenses came.
Toward the end of January reports began to reach Corregidor of the movement of Japanese artillery into Cavite Province. By the 25th, according to observers on the mainland, the Japanese had emplaced their guns in defiladed positions near Ternate, only about six air miles from Fort Drum on El Fraile Island and eight miles from the neighboring Fort Frank on Carabao island.
The reports were correct. A Japanese artillery unit called the Kondo Detachment was indeed moving into position along the southern shore of Manila Bay. Formed by 14th Army on 24 January, this unit was under the command of Maj. Toshinori Kondo and consisted initially of four 105-mm. guns and two 150-mm. cannons. Kondo's orders were "to secretly deploy" near Ternate and "prepare for fire missions" against Corregidor, El Fraile, and Carabao Islands and against shipping in Manila Bay. By the first week of February, despite interdiction fire from Fort Frank, Kondo had completed his preparations and was awaiting further orders.
He did not have long to wait. On 5 February, his orders arrived and next morning at 0800 the Kondo Detachment opened fire against the fortified islands. Fort Drum was the principal target that day and the Japanese guns hit it almost one hundred times during the three-hour attack. By accident or design, the choice of the early morning hours for the attack placed the sun behind the Japanese and made observation by the Americans difficult. They replied as best they could with their 14- and 6-inch guns, and Fort Frank assisted with its 12-inch mortars, but scored no hits. Thus began an artillery duel that was to continue intermittently for almost two months.
Until the middle of February the daily attacks followed much the same pattern. Major Kondo's 105s and 150s usually opened fire in the morning, to be answered by counterbattery fire from the large guns of the harbor defenses. later the Japanese fired at odd intervals during the day. Forts Frank and Drum, closest to Ternate, received the heaviest weight of shells and the greatest damage but their guns were never put out of commission and their effectiveness never seriously impaired. Damage to Corregidor was limited to occasional hits on buildings and vehicles.
During the course of the bombardment the Japanese hit upon a scheme to strike a vital blow at Fort Frank without firing a single shot. Learning from the natives that the fort received it supply of fresh water from a dam near Calumpan on the Cavite shore, they dispatched a demolition squad to locate and destroy the pipeline. On 16 February, the Japanese found the line and pulled up the section just below the dam.
Fort Frank, fortunately, had its own distillation plant and Colonel Boudreau, who had assumed command of the fort after the evacuation of Fort Wint in December, directed that it be placed in operation at once. But its use required valuable fuel and Boudreau was understandably reluctant to expend the gasoline he needed for his guns to distill sea water. On the 19th, therefore, he made an effort to repair the pipeline and sent a group of fifteen volunteers to the mainland for that purpose. Before the men could restore the line they were attacked by a Japanese patrol of about thirty men. In the fight that followed, the Americans and Filipinos, with the support of 75-mm. guns from Fort Frank, destroyed the entire patrol, suffering only one casualty. The fifteen men then returned to Fort Frank safely but without having accomplished their mission. That night the Japanese retaliated by burning the barrio of Calumpan. It was not until 9 March that Colonel Boudreau was able to repair the broken water pipe.
The intensity of the Japanese attacks increased after the middle of February, when Major Kondo received two additional 150-mm. howitzers. With these reinforcements came instructions from Homma "to demoralize the enemy." The daily bombardments thereafter became more severe and reached their height on 20 February. Starting at 0930 that morning the guns of the reinforced Kondo Detachment fired steadily at one-minute intervals until late afternoon. The only serious damage to was to the power plant on Corregidor and to several observation posts at Fort Hughes. After that date the Japanese fire diminished until, by the beginning of March, it presented no real threat to the harbor defenses. "In general," wrote the commander of the Seaward Defenses, "the Japs are resorting to nuisance firing daily and usually from a single gun."
The slackening of enemy fire at the end of February did not mean that the attack was over. On the basis of intelligence reports, General Moore concluded that the Japanese were merely "marking time waiting for reinforcements." This view was confirmed when native informants reported that the Japanese were selecting new gun positions in the Pico de Loro hills southwest of Ternate and improving the trails leading into the interior. In an effort to hinder this move, General Moore ordered his seacoast batteries to place interdiction fire on roads and bridges in the vicinity of Ternate, but without observable effect. The Japanese continued to make their preparation for a fresh attack without serious interference from the coastal batteries in the bay.
The Japanese force which assembled in the Pico de Loro hills during the first two weeks of March was considerably stronger than the Kondo Detachment. To that unit had been added the 1st Heavy Artillery Regiment, the 2d Independent Heavy Artillery Battery, both equipped with 240-mm. howitzers, and the 3d Tractor Unit with prime movers for the heavy guns. The Kondo Detachment had been dissolved and a new organization, the Hayakawa Detachment, formed. Col. Masayoshi Hayakawa, commander of the 1st Heavy Artillery, led the reorganized force, and, according to the usual Japanese practice, gave it his name. By 15 March all preparations for the stepped-up artillery bombardment of the harbor defenses had been completed.
The attack opened at 0730 of the 15th with a volley from the 240-mm. howitzers and continued throughout the day. Although all four islands came under, fire, Forts Frank and Drum bore the brunt of the bombardment. Approximately 500 shells fell on Fort Frank alone; another 100 on Fort Drum. Two of Frank's batteries, one of 155-mm. guns and the other of 3-inch antiaircraft guns, were almost entirely destroyed, and two other batteries were put out of commission temporarily. Fort Drum escaped more lightly. Its only damage came when a shell penetrated the armor of the 6-inch battery on the south side and burst inside the casemate, filling the concrete battleship with flames, smoke, and fumes. Fortunately, there were no casualties. Despite every effort during the day to neutralize the enemy fire, the bombardment continued until afternoon. "It hurt me like blazes," wrote Colonel Bunker on Corregidor," to see my friends under fire and be so powerless to help them."
The attack continued with unabated vigor the next day and with varying intensity for five days thereafter. As on the 15th, all four forts came under fire, but the weight of the attack was again directed against the two southernmost islands. The heaviest bombardments came on the 16th and 21st. On both days the concrete battleship fairly shook under the impact of the large shells. Every time one of them hit the casemate of the 6-inch guns a flash of fire was observed, and during the height of the attack there were fire alarms as often as every five minutes. Fortunately there was non general conflagration and no serious damage.
Fort Frank was not so fortunate. On the 16th a 240-mm. shell penetrated eighteen inches of concrete around one of its 12-inch batteries, passed under a six-foot concrete wall and exploded below the powder room. The floor of the battery was shattered and sixty cans of mortar powder overturned, but, miraculously, none exploded. It was on the morning of the 21st that Fort Frank suffered it "greatest loss" of the war when a 240-mm. shell penetrated the 18-inch concrete roof of one of its tunnels and struck in the midst of a line of men waiting for yellow fever shots. Twenty-eight of the men were killed and another forty-six wounded.
The damage wrought by the artillery attacks between 15 and 21 March was considerably greater than any inflicted by the 105s and 150s of the Kondo Detachment. Fort Frank, the larger target and the one closest to the enemy, was the most vulnerable of the forts and "got a fearful working-over." All of its surface guns--four 3-inch antiaircraft and four 155-mm. GPF guns--were visible to the enemy and were badly damaged. The depressed 12-inch mortar battery and two 14-inch disappearing guns were also hit, but were quickly repaired and put back in action. Fort Drum, the concrete battleship, came under as severe a bombardment as Frank, but was better able to withstand the battering. Every square foot of the interior surface of the casemates was deeply dented and torn by fragmentation, and between eight and fifteen feet of its reinforced concrete deck was whittled away. But though its two antiaircraft guns were ruined beyond repair, the principal target of the Japanese, the 14-inch turret guns, were never put out of action.
So heavy were the attacks against Frank and Drum that the commanders of both forts, fearing a hostile landing, had doubled their beach defenses immediately. This precaution was a wise one, for the Japanese did actually plan to capture both Forts Frank and Drum, and had even designated the unit which was to make the assault. General Homma canceled this plan, however, in order to strengthen the force he was assembling late in March for the final attack against Bataan. The landing craft which had been collected for the attack, about forty-five bancas, were later destroyed by 75-mm. gunfire from Fort Frank.
Throughout the long-range artillery duel the effectiveness of American counterbattery fire was limited by the difficulty of locating the Japanese guns. There was no flash during daylight, and both Kondo and Hayakawa were careful to take very precaution to avoid giving away their position. They camouflaged their guns skillfully, moved them when necessary, and even sent up false smoke rings when their batteries were in action. The American and Filipino artillerymen tried to fix the enemy's position by the use of sound waves, but this method proved too delicate and complicated. Another method, admittedly less accurate but easier to use, was to compute the enemy's position by the line of falling duds. The results could rarely be checked, but the batteries of all four forts fired daily, hopeful that they might knock out some of the Japanese guns with a lucky hit.
For a time firing data was received from a small group of volunteers on the mainland led by Capt. Richard G. Ivey of the 60th Coast Artillery (AA). Ivey had established an observation post on high ground along the south coast of the bay and, until he was driven out on 15 February, served as a spotter, sending his information by walkie-talkie radio. Even this observed fire proved of doubtful effectiveness. During one bombardment, when Ivey's reports appeared inconsistent, the fire control center asked him how he knew there was a Japanese gun in the position. "He replied," wrote Colonel Bunker, "that he couldn't see it, but judged by the sound that it was there." When fire was shifted to another target, the observer's instructions, which failed to distinguish between deflection and range, were just as confusing and the fire was discontinued.
Rarely was General Moore able to secure the services of the few remaining aircraft to fly reconnaissance. When he did the results were most gratifying. One such occasion came on 9 February, when Capt. Jesus A. Villamor, in an obsolete Philippine Army training plane equipped with a camera, set out to take photographs of the Ternate area. Protecting his slow and unarmed biplane were six P-40s. Villamor completed his mission, but on the way back the formation was attacked by six enemy fighters. While Villamor came in with his precious photographs, the P-40s engaged the enemy in a spectacular fight over Bataan. in the space of a few minutes the American pilots brought down four of the enemy fighters and fatally damaged the remaining two. Only one P-40 was lost. Meanwhile the photographs taken by Villamor were printed and rushed to Corregidor where they were collated with reports from observers on the ground. The counterbattery fire that followed proved remarkably accurate and several direct hits were scored.
The difficulties of counterbattery fire were further increased when the Japanese moved their guns to the Pico de Loro hills where they could be reached only by high trajectory fire. Few of the coastal guns in the harbor defenses, which had been designed for use against warships, had sufficiently elevation to clear the high ground before the enemy positions. Their difficulty is illustrated by the experience of the men of Battery Hearn on 21 March, who, "in a desperate effort to silence the Japs," opened fire with their 12-inch guns. "We wound up," Colonel Bunker, wrote, "with our guns elevated against he elevation stops--and that wasn't any too much."
The only weapon in the armament of the harbor defenses with the high trajectory required to deliver effective counterbattery fire under these circumstances was the 12-inch mortar. There were twenty-two of these pieces on the four islands, but their usefulness against land targets was limited by the lack of sound ranging equipment and the shortage of ammunition with instantaneous fuzes. There was an ample supply of armor-piercing, fixed, delay fuze ammunition with a small bursting charge. This type was designed for use by coast artillery against warships but was of little use in the situation in the Seaward Defenses then faced. These shells buried themselves deep in the earth before exploding and caused little damage to men and installations near by. The ideal ammunition against the targets presented by the Japanese guns on the Cavite shore was the personnel type with instantaneous point detonating fuze. There were about 1,000 such shells, of 12-inch caliber and weighing 670 pounds, but even this small amount could not be used freely, for it would be desperately needed when Bataan fell and the enemy placed his heavy guns on the slopes of the Mariveles Mountains.
A small quantity of additional instantaneous fuze ammunition was obtained as a result of experiments made by Colonel Bunker. He modified the fuze of the 1,070-pound shells used in the 12-inch guns by removing the .05-second delay pellet, thus detonating the shell more quickly. When he test-fired two such shells he got "beautiful results, up to my wildest hopes." The effect, he noted, was equal to that of a personnel shell, "both in dirt thrown up and in noise made," But thought the modified projectile exploded on impact, it had only a small bursting charge and a limited effect. Thus, despite every effort to secure effective counterbattery fire, the Americans were never able to prevent the Japanese from firing almost at will.
The artillery duel which had begun early in February came to an end on 22 March. Though the Americans reported artillery fire from the Cavite shore until early in April, it could not have come from the Hayakawa Detachment. That force had been disbanded on the 22d and its elements ordered to rejoin their parent units for the final attack against Bataan, then about to open. Whatever guns remained behind were of small caliber and were intended only to annoy the defenders.
F O O T N O T E S
 14th Army Opns, I, 13-14.
 Ibid., 96.
 Harbor Defenses Rpt of Opns, p. 37. The claims made by the volunteers were accepted by General Moore and have been used by the author in the absence of any evidence to the contrary.
 14th Army Opns, I, 115.
 Bunker, DIary, entry of 19 Feb 42.
 Harbor Defenses Rpt of Opns, p. 38.
 Bunker, Diary, entry of 15 Mar 42.
 Maj Joe C. East, March 21st Fort Frank Shelling, a 2-page typescript in OCMH.
 Bunker, Diary, entry of 15 Mar 42.
 Ibid., entry of 15 Feb 42. The italics are Colonel Bunker's.
 Ind, Bataan: The Judgment Seat, pp. 288-92.
 Bunker, Diary, entry of 21 Mar 42.
 Ibid., entry of 5 Mar 42.