The final preparatory barrage lasted from 0730 to 0830 on the 23d. Using both area and point fire, the artillery, tanks, TD's, SPM's, and mortars plastered the walls of Intramuros and covered the entire interior except for a section roughly three blocks wide and four blocks long in the west-central portion of the Walled City. At 0830 the support fire ceased, and the infantry assault began. Ten minutes later artillery began firing again, this time laying the high explosive, smoke, and white phosphorus along a 100-yard-wide strip between the east and west walls to seal off the southern third of Intramuros and prevent the Japanese in that area from observing movements to the north or sending reinforcements northward. This fire lasted approximately half an hour. Table 4 gives the amounts of artillery fire expended in support of the assault. The total weight of the artillery fire was roughly 185 tons, to which the 4.2-inch mortars of Companies A and D, 82d Chemical Mortar Battalion, added about 45 tons--over 3,750 rounds--of smoke and high explosive.13

 

XIV Corps Artillery reported that by reason of their great accuracy the 8-inch howitzers were the best weapon used against the walls while the 240-mm. howitzers, with their heavier and more powerful projectile, proved most effective against buildings. With 155-mm. howitzers, considerable advantages seemed to have accrued by employing unfuzed high-explosive shells to open fissures in the walls, since the unfuzed shells penetrated more deeply before explosion than did those with impact or delayed fuze settings. The fissure thus opened was easily enlarged by subsequent employment of high-explosive shells with delayed settings.

TABLE 4 
ARTILLERY EXPENDED IN SUPPORT OF THE ASSAULT ON INTRAMUROS
Caliber Rounds

  High Explosive Armor Piercing Smoke and White Phosphorus
 
75-mm. tank guns 450 150 . . . .
76-mm. TD guns 450 150 . . . .
105-mm. field artillery howitzers 4,753 . . . . 93
155-mm. field artillery howitzers 1,723 . . . . 23
240-mm. howitzers 39 . . . . . . . .
8-inch howitzers 72 . . . . . . . .
     Total 7,487 300 116
Source: Relevant sources cited in n. 12.