Located on Carabao Island.
Battery Koehler
12" mortar battery. First fired on January 31, 1942. A total 30 rounds were fired at gun positions near Ternate by the mortars. On February 6, 1942 on mortar suffered a muzzle burst. Casualties were one Philippine Scout killed and seven wounded, including Captain R.J. White, the battcry commander.
Battery Frank North
On February 18 the Japanese concentrated most of their fire power on Fort Frank. At 9:30 p.m. they scored a hit on Battery Frank North Number 4 gun wounding seven of its crew.
Battery Ermita
March 2 shot down one aircraft. On March 6 when it shot down a Japanese plane on reconnaissance over the fort.
Crofton Tunnel
The morning of March 20th, the garrison was lined up in Crofton Tunnel to be inoculated. While waiting in line 240mm shell penetrated the roof of the tunnel and exploded. Killed were 28 men while 26 were wounded, several of these latter mortally. The wounded and dead were removed that night to Fort Mills. This did not prevent Battery Koehler from firing back at the enemy this night or the next day.
Japanese Bombardmend of Fort Frank
As Japanese forces entered the Pico de Lora HilIs and the Kondo Detachment setup four 105mm and two 150mm guns for the bombardment of Fort Frank. In mid-February another two 150mm guns would be added to this force. Shelling continued until March 20th when the last 240mm howitzers from Cavite as the Hayakawa Detachment was disbanded on March and its guns transferred to Bataan.
Counter battery operations carried out against Japanese positions in the Pico de Lora Hills. As the Japanese usually held their fire until the sun was at their back, visual plotting of the batteries from Fort Frank was almost impossible. In order to overcome this handicap Captain Ivey and a small party of enlisted men crossed to the Cavite shore. Here for a few days they were able, by walkie-talkie, to direct Fort Frank's and Drum's, guns on to targets. The Japanese due to the accuracy of the American fire, suspected that a forward observation post was operating in the vicinity and conducted an infantry sweep of the area dislodging Captain Ivey's party and finally forcing it to return to Fort Frank on February 15.
Shortly after 8 a.m. on February 6, 1942 Japanese 105mm and 155mm howitzers and guns on the Cavite mainland opened fire on Forts Drum, Hughes and Mills. This fire which lasted until almost 11 was returned by Battery Roberts at Fort Drum and Batteries Koehler and Frank North at Fort Frank. Surprisingly Fort Frank was not subjected to any Japanese artillery fire this day.
The following day the Japanese included Fort Frank in their bombardment. From this time on, all the Manila Bay forts were to suffer from Japanese guns on the Cavite mainland. This fire was answered by all the forts and in particular Fort Frank. The lack of forward observers to adjust the first of the American guns however, greatly reduced their effectiveness. To help correct this problem on February 9 a photographic flight was made over the Cavite shore. These pictures were of some temporary help in connection with Captain Ivey's radio reports. The pictures however became of less value after February 15 when the Japanese shifted their gun positions.
On February 16 the Japanese struck what appeared to be a death blow to Fort Frank, by blowing up the pipeline that carried fresh water from the Calumpan Dam on the mainland to the fort. Though Fort Frank had a distillation plant that was not put into operation, it was vulnerable to shell fire and low on fuel. Japanese troops were in such close proximity to Fort Frank that the following day the three 75mm beach defense guns were able to open on Japanese troops moving about in the open on the mainland.
On February 18 the Japanese concentrated most of their fire power on Fort Frank. As the shells continued to hit in and around Carabao Island the harbor boat Neptune tried to approach Fort Frank to deliver supplies. Forced to pull away from the pier once due to the shelling she returned again at 3:30 a.m. on February 19. As Neptune started to tie up to the pier she was hit on the bow by a Japanese shell that set afire 15 drums of gasoline intended for the fort's generators, and 500 powder charges for the 155mm guns. The gasoline blaze quickly had Neptune afire from bow to stern and the crew abandoned over the side. All supplies aboard the ship were lost. In addition, floating burning gasoline came ashore and set the island's vegetation on fire in a number spots. It was only with great difficulty that the blazes were extinguished.
Loss of the gasoline supplies heightened Fort Frank's critical fuel problem. To conserve fuel, Colonel Boudreau called for volunteers to return to the mainland and repair the blown water pipe. A party of 15 men landed later that day and began to repair the water pipe. While so engaged they were attacked by a number of Japanese, but assisted by Fort Frank's 75mm gut beat off the attack, killing 25 to 30 of the enemy. The engagement however prevented the water line from being repaired.
Starting at 9:30 a.m. on February 20 Fort Frank along with Fort Mills and Hughes was subjected to a shelling that saw a round hitting each fort on an average of one a minute until late that afternoon. The next day was peaceful as the Japanese ceased firing to reposition their artillery. Battery Frank North however was active on February 29 taking under fire Japanese troops near Ternate and Maragondon on the Cavite mainland while the 75mm guns fired on Japanese troops at Calumpan on February 26. The lull which now took place was put to good use by Fort Frank and the other forts as they strengthened fortifications and repositioned guns.
A further cut in the food issue at Fort Frank and the other forts came on March 2 when each ration was cut to three-eights normal issue. That same day an attack by two dive-bombers caused little damage to the fort but resulted in one aircraft being shot down by Battery Ermita. A few days later Battery Koehler's 12 inch mortars hit Japanese artillery positions being prepared near Pico del Oro. Koehler's salvos of eight 670-pound shells, when equipped with instantaneous fuses, were the most effective counter-batter instrument possessed when using high explosive shells, which were in short supply, did little real damage as most of the shells fired were armor piercing and thus exploded only after penetrating the ground for some distance. Only batteries Frank North, Ermita and 75mm guns had any large number of high explosive shells.
Battery Ermita drew blood again on March 6 when it shot down a Japanese plane on reconnaissance over the fort. It was also on this day that a Filipino civilian delivered to the fort a Japanese demand for its surrender. The substance of the message according to General Moore This demand for surrender was ignored.
With fuel stocks running low a new attempt was made on March 9 to repair the water line. Under cover of a barrage of shells from the 75mm guns a party landed on the mainland and after nine hours repaired the break. Amazingly, the Japanese did not interfere with the repair of the waterpipe though it lay on ground they occupied. For the remainder of March, Fort Frank was to have ample water.
The first part of March saw the 75mm guns firing numerous rounds of shrapnel at enemy concentrations while Battery Frank North struck at supposed Japanese gun positions. The enemy reply to these shots was feeble or non-existent. This, however changed on March 15 when the Hayakawa detachment's two 240mm howitzers opened fire on Forts Frank and Drum. At this same time 155mm guns also hit Mills and Hughes. Hardest hit was Fort Frank which lost two guns each at Batteries Frank North and Ermita to direct hits, plus repairable damages to the other guns of these batteries. AIso destroyed was a machine gun post, while Battery Koehler had seven of its mortars damaged. In all more than 500 shells hit Fort Frank this day.
Next day the bombardment continued. General Moore's after-action report stated of this continued bombardment: "A 240mm shell hit at junction of the vertical wall and emplacement floor at Battery Koehler, penetrated 18 inches of concrete, passed under a 6-foot concrete wall and exploded under the powder room. The floor was broken up and 60 cans mortar powder overturned but none was set off."
On the following day Battery Koehler was back in action but still under fire from the Japanese. Counter fire from Fort Frank and the other forts was light in comparison with the Japanese barrage. The principal targets on Fort Frank were Batteries Koehler and Crofton. Battery Crofton from this time was to suffer on a number of occasions damaging near misses. It was able only to remain in operation by cannibalizing parts from Battery Greer. As soon as Crofton opened fire the Japanese would bring a wall of fire down around the open battery.
For the remainder of March and the first part of April a continued exchange of fire fights occurred between the Cavite shore and Forts Frank, Drum and Hughes. The exchange was fairly one-sided, however, as the Japanese had a secure supply line and observable targets. The morning of March 27 brought a new threat to Fort Frank when 45 bancas were observed assembled on a mainland beach south of the fort. Fearing an amphibious assault these boats were taken under fire by the 75mm guns and destroyed. These bancas in fact had been gathered for an assault on Fort Frank, but the troops assigned to the attack had to be shifted to Bataan to support the fight there.
The final phase in the reduction of the Manila Bay Harbor Defense forts started on April 9 with the fall of Bataan. Japanese artillery could now be shifted to Bataan close to Corregidor, the main link in the Manila Bay defense. On April 10 Fort Frank permanently lost its mainland water supply when the Japanese removed two lengths of pipe from the water line. As no extra pipe existed, Fort Frank was unable to repair the break and was forced to fall back on its distillation plant. Though the 240mm howitzers were gone, Fort Frank still suffered from Japanese 155mm gun fire and occasional air attacks. This shelling and bombing was of sufficient intensity and accuracy to prevent any significant firing of Fort Frank's guns at targets of opportunity and in conducting counter battery fire.
On May 5, 1942, as the Japanese commenced an amphibious assault on Corregidor, General Wainwright told General Moore that he proposed to surrender at noon. He then ordered General Moore to instruct his troops to destroy all their weapons larger than a .45 caliber pistol and to hoist a white flag. This instruction was transmitted to Fort Frank and complied with by Colonel Boudreau. Japanese troops shortly thereafter peacefully occupied Fort Frank. The American garrison however was not evacuated to Manila until May 24.
Japanese Occupation
Japanese over the next three years were to recommission battery Crofton and add three 100mm guns. The American landing on Luzon on January 9, 1945, found the forts of Manila Bay garrisoned by a miscellaneous group of Japanese soldiers, designated the Manila Bay Entrance Defense Force under the command of Captain Akira Itagaki. Plans were set forth to recapture the Manila Bay forts. First to fall was Fort Mills. followed by Drum and Hughes. The fight for these forts was long and bitter resulting in high casualties for both sides in relation to the size of the objective.
The garrison of Carabao, based upon intelligence from a captured organization chart and prisoner interrogation, was estimated at 500 men. These were thought to be principally elements of a Japanese Naval landing unit.
American Liberation
Prior to the assault the island was taken under fire from the Cavite shore: 105mm and 155mrn Howitzers supported by 81mm and 4.2" mortars (fired by 82nd Chemical Mortar Battalion). Added to this was bombing by medium bombers and fighters dropping and 1,000 pound bombs and C-47 transports dropping 55 gallon drums Napalm. This was supported by gunfire from cruisers, destroyers and rocket ships. Principal target for the ships was the sea wall protecting the proposed landing area. This had to he knocked down if .a broad front (200 yards) was be provided for the landing. So intense was the bombardment that vegetation was stripped from the island.
Assault waves of the 1st Battalion of this 151st Infantry went ashore 9:03 a.m. April 16, 1945 supported by C Company, 113th engineers. The initial wave consisted of two platoons, one securing the beachhead while the other advanced to capture the crest line. Following units placed a block across the north side of the connecting ridge and then occupied the south side of the island. This was followed by securing the western peninsula and then the northern end of the island.
No enemy troops were encountered in the sweep but a number of supply dumps were found and destroyed, while all caves were sealed by engineers using explosives and a bulldozer that had been winched to the top of the hill. The only living object found on the island was a pig. Investigation of documents found showed that the garrison had slipped ashore to Cavite the week before the assault. Though no resistance was encountered in the capture of Fort Frank, five men were killed and 18 wounded in an undetermined explosion about 11 a.m. Three causes were suggested for the explosion: a booby trap, a short artillery round, or a premature explosion of a demolition charge.
Today
The post-war American and Philippine occupation of Carabao brought no attempt to restore the fortifications. When the Philippine government took possession of Carabao Island in 1946 it at first maintained a small garrison, but this was later withdrawn. Since then unauthorized scrap metal collectors have stripped Fort Frank of all its armament and have started to break up the concrete for its iron reinforcement rods. What the scavenger has not taken away is reclaimed by the jungle.
