The Japanese Navy: “Kon” Operations to Relieve Biak

by Dr. Hargis Westerfield, Division Historian from Naval and Air Historians

During 2-13 June 1944, our 41st Division came as near destruction in World War II as it ever would. The Japs mounted three "KON" or "sea army" operations against us. Without the aid of the U.S. Air Force and especially our weaker Yank and Aussie fleet, Jap guns would have sunk our LSTs and destroyer guards offshore. Jap guns would have pulverized our beachhead into bloody froth. A Jap Special Landing Force would then have driven us against the reinforced Jap defenders of Biak. God surely took a hand in our salvation for the failure of KON Operations was ultimately due to forces beyond our Army and Navy and Air Force control.

Main reason why Jap admirals wanted to crush our 41st on Biak arose from fear of a new Biak air-base. Their supreme battle-fleet hoped to demolish our Navy in the Philippine Sea north of New Guinea. Our new air-base on Biak would put their fleet in mortal danger.

On 2 June 1944, KON I assembled in Filipino Davao Gulf. Called the KON or "sea army" fleet, it was formidable against our weaker Navy in Biak waters. Besides an old battle-ship (Fuso), it consisted of three heavy cruisers (Aoba, Myoko, Haguro), one light cruiser (Kinu), eight destroyers, two mine-layers, and smaller craft. It carried a new special landing force, two Amphibious Brigade of 2500 - perhaps three Infantry Battalions, 12 75mm cannon. This fleet expected air cover from the reinforced Jap 23 Air Flotilla which would strike from Sorong and other New Guinea fields west of Biak.

When this deadly KON I fleet left Davao Gulf about 2400 2 June, it had a horrible opportunity to kill our 41st. Despite submarine and plane reports of Jap Navy movements, General MacArthur's G-2 wrongly believed that fleet elements were merely convoying supplies and troops for Davao or the Palau Islands.

Except for perhaps six destroyers covering the beachhead, our Navy was far from Biak. Only on 3 June - the day before KON's expected arrival - did Allied Naval Forces order a weak fleet to head for Biak. To oppose the Japs' Battleship Fuso, three heavy cruisers, one light cruiser, eight destroyers, we had only one heavy cruiser, three light cruisers, ten destroyers. Their battleship and heavy cruiser could sink Rear Admiral V.A.C. Crutchley's squadron while still out of range. This Aussie commanding officer would have fought at night when our Hollandia and Biak air cover would have been useless.

But the Jap invasion plan had a fundamental weakness. The plan did not provide an effective air-force. Although Jap Headquarters had reinforced their decimated 23 Air Flotilla at Sorong with 166 planes, most of those planes never fought over Biak. On arrival in New Guinea, most of the pilots took malaria. Some pilots fought, of course. On 2-3 June, raid of only some 50 Jap planes swooped on Biak. We had no air cover, but a sheet of flame struck from our Ack-Ack around Bosnek downed 23 planes, with small damage only to Destroyer Reid, LTS 467.

The blunder of a Jap recon plane was the main reason KON I failed. About 2025 3 June, the recon pilot saw a strong U.S. carrier force approaching Biak. Maybe the pilot was malarious. Maybe he mistook destroyers for battleships, LSTs for carriers. Maybe he merely saw Crutchley's weak fleet from Hollandia.

KON I's commanding officer had already reported a periscope of ours that watched his fleet in the Philippine sea. Two Navy bombers had traced his moves. Now Rear-Admiral Naomasa  Sakonju got orders from Jap Combined Fleet Headquarters to withdraw. For the moment, our division was saved. Only important U.S. loss was light cruiser Nashville, holed in an air-raid.

KON I failed - except for a minor success. While U.S. attention was on KON, some Japs slipped through from Mankowari to reinforce Colonel Kuzume. On that tense night of 3-4 June, Captain Ozawa's 6 Company 221 Infantry and two light guns landed at Korim Bay, and perhaps 5 Company 222 Infantry. This landing was small success for the Japs' lost chance to wipe out Bosnek and our shipping with Battleship Fuso's twelve 14" guns.

KON II followed immediately. Probably air recon, early on 4 June, informed the Japs that we had no carriers in Biak seas. Now, instead of larger, slower cruisers, the Japs tried to slip in six destroyers. Of these six destroyers, three were to carry 200 infantry apiece; and three (or maybe six) were to tow a landing barge apiece, with 30-50 men to a barge.

Leaving Sorong on the far western end of New Guinea about midnight 7 June the six destroyers coasted the farthest northern point of New Guinea, the Cape of Good Hope. At dawn, they expected air cover from six planes of their 23rd Air Flotilla. On 8 June, KON II's success appeared certain. Without carrier plane opposition, they were safe because most of our heavy bombers had massed for Palau Islands far north. Jap raids of 5-6 June on Wakde Strip had caught over 100 of our planes parked wing to wing, and made the Strip useless.

Yet KON II found trouble in broad daylight in the seas north of Cape Good Hope. About 1330, P-38 fighters from Hollandia Strip attacked the covering six Jap planes. The P-38s shot down at least three Japs, drove off the others. With eight fighters protecting them, ten B-25 bombers swooped on the destroyers. (Other sources alleged that we had 50 planes.) Attacking in pairs, they shot in mast-high. Before Squadron Leader Major Tennille got his plane into bombing position, two destroyers' concentrated fire tore his plane apart, slew him and 2nd Lieutenant Wood. But their sacrifice enabled other bombers to crisscross the six destroyers with low-level strafing and bombing.

An underwater bomb exploding holed Harusame; she sank in five minutes. A fragment penetrated Shiratsuyu, but she did not slow down. Strafing damaged topsides of Samidare and Admiral Sakonju's Shikanami. We lost three bomber crews.

But when our planes left, the Japs rescued Harusame's castaways and steamed on for Biak. Then about 1800, a flyer reported that a fleet was speeding at the little convoy from east of Biak: one battleship, four cruisers, eight destroyers. No doubt Sakonju remembered that erring plane report of 3 June that aborted KON I. Valiantly, he drove on into tropical night. The moon rose at 2023, two days past full. Passing showers often hid that moon.

This time, however, a battle-fleet was coming, far heavier than Sakonju's. Admiral Crutchley came for a kill - with Aussie heavy cruiser Australia, Yank light cruisers Phoenix, Boise, fourteen destroyers, two of them Aussie.

Crutchley's first contact occurred when a recon plane spotted five Jap planes 60 miles northwest of Korim Bay. Crutchley sent U.S. destroyer Mullany to check the dark little fjord. The Japs had not arrived. About 2320, a Jap plane marked Mullany with a flare, but the bomb missed by 100 yards.

After Mullany rejoined us, cruiser Boise, Yank forward destroyer Fletcher, and Sakonju made radar contact at 2320 - at 23,400 yards. Outgunned Sakonju turned to escape. Destroyers cast off their towed barges of Jap infantry and turned north.

Although Admiral Crutchley had ordered Yank Commander Jarrell to fall back to the fleet's port quarter, Jarrell probably disobeyed. Three miles ahead of Crutchley, he was working speed up to 30 knots. Nine minutes later, Jarrell opined that the Japs had loosed torpedoes. Eleven minutes later, cruiser Boise saw a torpedo in her wake. All our cruisers turned north; the torpedoes missed.

The Japs ran northwest at 32 knots - in two lines, three ships on the left, two on the right. Three minutes later, we passed the castoff barges of Jap Infantry, and fired on them, results unreported.

We settled into a long stern chase - our destroyers at 35 knots, slower cruisers at 29 knots. Commander Jarrell's four-destroyer division was closest to the fleeing Jap. Racing parallel to Jarrell on the north was Commander McManes' division with four destroyers - but 7,000 yards behind Jarrell.

By 0018, Commander Jarrell had closed down his flagship Fletcher's range from 23,400 yards to 17,000 yards. He now ordered Fletcher to open fire. At this distance, Jarrell hardly expected a hit, but he hoped that the Japs would zigzag to avoid shells, and lose distance. But Sakonju trusted in speed and kept on in two straight lines.

By 0045, Crutchley was sure that no Jap cruisers supported the destroyers. With eight of his destroyers closing in on just five Japs, he had no reason to burden his slower cruisers any longer at full speed ahead. He ordered destroyers to continue pursuit until 0230, when they would have good reason to break off. At 0100, before Jarrell's first shots, he turned the cruisers back at 15 knots, with a four-destroyer screen, and sent Aussie destroyers Arunta and Warramunga to find the cast-off Jap barges, but with no reported results.

Our pursuing destroyers were closing range on the Japs, but orders were to cut off pursuit in 65 minutes. At 0125, Jarrell tried to trick the Japs into destruction. At 13,000 yards, he directed all of his four destroyers to turn to port and shoot broadsides. During those seven minutes, we saw the bright flare of Jap gunfire through heavy smoke columns.

Jarrell had rightly assumed that the Japs did not know that Mcvlanes' division was closing in on them from the right. Replying to Jarrell's broadsides, the two Jap destroyers on his right also turned rightwards. First, they shot torpedoes; at 0144, a torpedo track passed Jarrell's Fletcher.

While the Japs' two destroyers turned and lost speed and distance, Commander McManes' four destroyers had cut their range to 15,000 yards; at 0205 they opened fire. In six minutes, we saw an explosion on destroyer Shiratsuyu. She lost 1,000 yards at first, then picked up speed. At 0227, our range was down to 10,000 racing yards, but we could get no nearer.

In the entire two hours of the chase, we had exchanged 1,300 rounds with the Japs. Besides "straddling" Shiratsuyu, we had slightly damaged Samidare, and Flagship Shikananami. But even our most endangered Jarrell's Fletcher was untouched.

For good reasons, we broke off the chase. The seas west of Mapia Island were restricted for Yank planes; they might bomb us by mistake. During daylight, destroyers needed safety under fighter cover, close inshore.

KON II did not wholly fail; some Japs in the barges reinforced Kuzume on Biak. Perhaps 2-3 barges landed men of either 2nd Battalion or 3rd Battalion 219 Infantry - maybe 5th Company, 222 Infantry.

KON III was the final plan of the frustrated Jap Navy against Biak. Core of this invincible fleet was battleships Musashi, Yamato, superior in power world-wide, with a total of 18 18" guns. (Battleship Fuso of KON I had just 12 guns of only 14" caliber.) Supports were heavy cruisers Myoko, Haguro, Aoba, light cruisers Noshiro, Kinu; and seven destroyers. Without turning back, they were to pulp Bosnek and Owi, and land troops.

Although positioned at Batjan Island southwest of Morotai on 12 June, this fleet never struck Biak. On 13 June, it sailed east to help defend the Marianna Islands from our 5th Fleet.    

We never suffered Naval bombardment in all three KON Operations; but we fought a sizable Jap infantry reinforcement infiltrating during this time. As mentioned already, in KON I and II, probably two Companies, two guns, and 2-3 other barge-loads landed on Biak. Otherwise, Jap records are vague. Conclusions are that, during 3-25 June - ending 12 days after KON III aborted - these numbers arrived: 225 men of Kuzume's own 222 Infantry, 400 of 221 Infantry, and 500 of 219 Infantry. (Not a man of the Navy's 2nd Amphibious Brigade ever landed.) Total was about 1125 infantry, a fair-sized assistance to Kuzume's 4000 infantry already on Biak, and 7,400 other troops.

These 1125 men surely delayed our capture of Mokmer Drome. They prompted General Fuller to request reinforcements on 13 June, and so helped effect his request to be relieved from 41st Division command.

But besides losing Destroyer Harusame, the Japs took more significant losses from KON - almost all trained pilots who reinforced 23rd Air Flotilla against Biak. They lost maybe half from malaria or combat over Biak. Most of the others died from bad weather or our Air Force when trying to return to the Mariannas.

At the time of the KON Operation, we seemingly had no idea of the menace to our Division. In KON I, only an erring Nippo pilot's report saved us from Fuso's twelve 14" guns. In KON I, our 5th Fleet's Mariannas attack saved us from Musashi's and Yamato's eighteen 18" guns. We can well say that the hand of God saved our 41st Infantry Division.


CREDIT. Books already published were my sources here, for their authors have researched this area of our history further than I need to go. Books included Japanese Operations in the Southwest Pacific Area, from "Reports of General MacArthur;" Samuel Eliot Morison's History of U.S. Naval Operations in World War II - Vols II, V, and VIII; and Walter Karig's Battle Report / The End of an Empire. Also useful were Frank Craven and James Cate's Army Air Forces in World War II, Vol IV; George C. Kenney's General Kenney Reports; and R. R. Smith's Approach to the Philippines. Smith is finely detailed on possible Japs' troop landings, but he omits much of interest about our Navy and Air war, which I gathered mainly from Morison and Karig. Kenney is best on the saga of Major Tennille.