The 3rd Bombardment and final tightening of the noose (June 22-June 24)
Admiral Niimi and General Tanaka now order the next step in finishing off the American fortress. The Army has moved its heavy 240 mm guns (8 operational), and 150 guns (8 operational) from the Malaria pesthole of Bataan to the somewhat less disease ridden Cavite province, joining the Kondo detachment (4 x 4.7 inch howitzers, 2 x 150 mm howitzers). On Bataan the remainder of the 7th Artillery command is in position with 36 x 105 mm guns, 48 x 75 mm guns, but for now those guns remain silent as their crews will not be moved into position until it is time for to cover the amphibious assault planned for July 5. Joining the bombardment force are the crews of 18 x 90 mm mortars which are ferried over to the newly captured Fort Hughes during the nights of June 22 and June 23.
For the air bombardment, the Army has 24 light bombers, 60 medium level bombers, 9 reconnaissance aircraft, plus several observation balloons (deployed at Bataan and Cavite provinces). The Navy has 27 dive bombers and 30 float planes assigned to the mission. Other Navy aircraft (flying boats, float planes and medium bombers) are patrolling the waters around the Philippine Islands.
Shipping delays have kept sufficient ammunition (and a number of replacement guns to substitute for those worn out in the previous two bombardments) from reaching their deployment areas until June 23. But now everything is ready. The final bombardment is ready to begin.
At 0900 hours the Army medium bombers make their attack at 12,000 feet, while Army light bombers come in at 8,000 feet with orders to attack American AA guns as they fire. The Americans only have 9 3 inch guns remaining, scattered around Topside but still have a large number of heavy machine guns scattered on Topside and on Malinta Hill. American flak now lacks centralized control and is forced to rely on local sights, so the accuracy is far diminished, although the relatively low level of the attackers makes up for this somewhat. Several Japanese bombers are heavily damaged by 3 inch bursts, 2 more are shot down, and bombing accuracy is poor and none of the bombs land in the gun pits of Battery Geary or Battery Way (where a single mortar remains operational at each). The light bombers attack the flak guns as they are spotted, but heavy machine gun fire damages most of the Army bombers, and 5 crash into the sea. The Japanese consider the attack a success however, as all of the American anti-aircraft guns are spotted by observation balloons and their location is quickly forwarded to Japanese gunners.
At 0910, a massive barrage begins, with every Japanese heavy and medium gun opening up at once, and shells rain down on American anti-aircraft positions. This quickly slows down in pace, but one shell is landing every minute on those positions and this continues for the next 5 hours. The defenders suffer heavy casualties, with the 1st and 2nd battalions 60th Coast Artillery losing nearly half of its men within the first few minutes as the shellfire catches many as they attempt to reach cover or are still at their guns. Only 4 of the 3 inch guns survive the bombardment, and all of them are damaged to the point of being non-operational while the remaining guns are hopeless wrecked.
An afternoon bombing raid by Army bombers meets no flak at all, and bombing is thus superb, with bombs hitting every gun pit and a followup strike by Navy dive bombers a few minutes later is equally successful. Spotter planes are now able to fly over the island at medium altitude and when shelling resumes a couple of hours before dark, and heavy shells blast apart the 12 inch mortars of Fort Mills, destroying every one.
The defenders suffer a very bad day, with nearly 600 casualties taken (including 140 dead) and their flak guns and heavy mortars are now effectively out of the fight. The Japanese can now bomb at medium level with impunity. Worse, the Japanese can now fly comfortably overhead and spot their fire easily.
As night falls, the bombing and shelling ends for a few hours, from 1700 Hours until 2200 Hours. The Japanese take this time to feed and rest their gun crews, move up more ammunition and prepare for the night to come. The Filipino-American defenders take this time to recover their many casualties and to assess damage.
Beginning at 2200 hours, the next phase of the bombardment begins. Shell fire begins at a steady pace, with 1 round landing every minute from heavy and medium guns aimed to cover the entire island over the course of the night as harassment. This keeps the defenders under cover and also covers the noise of the Japanese float planes as they make several passes over the only remaining anchorage area available to the American submarines and drop a total of 56 mines that night. Deafened by the bombardment, the defenders fail to notice this, and it also becomes clear that attempting to move troops around the island to Cheney ravine is now highly risky and certain to produce result in casualties.
At 0500 the shelling ends, and again the Japanese take a break until 0900 when the next bombing raid begins. This time there is no flak available, and the Japanese bombers plaster battery James and Morrison, wrecking the 6 and 3 inch coast defense guns there and suffering no losses. At noon the heavy guns open up again, concentrating on Battery Stockade, destroying the 155 mm guns there before the Japanese again take their dinner break. A bombing raid completes the day, this time consisting of small bombs dropped all over Topside aimed at producing casualties, although few are inflicted.
Night falls finally after a grueling couple of days for the Filipino-American defenders. Meanwhile, the submarines Barricuda, Bass and Bonita are approaching their planned anchorages just off Cheney ravine.
My knowledge of Philippine history is pretty sketchy too, but just thinking on the larger scale for your universe, they would have a very large number of NCO's, and more junior and senior level officers from all services, who have persevered - and had a few successes too. The pool of talent would be much larger than OTL. That larger leadership pool could help draw more international investment maybe? Send W. Edward Demings to the Philippines instead of Japan maybe....
