Tactics Rule at Empress Augusta Bay

Some authorities believe the struggle for the Solomon Islands—not the battle of Midway— was the turning point of World War II in the Pacific.¹ After Midway, the Imperial Japanese Fleet was still more powerful than the U.S. Fleet.² But the war of attrition during the 15-month Solomons Campaign was a war Japan never could win (though this was not clear at the time). When Japan’s great naval base at Rabaul on New Britain became vulnerable after the Allied conquest of Bougainville, the way was open for the pincer movement of Fleet Admiral Chester Nimitz’s Central Pacific Offensive through the Gilberts, Marshalls, Carolines, and Marianas and General Douglas MacArthur’s thrust north from Australia through New Guinea to the Philippines. Together, the two operations led to victory.

Midway usually is cited as proof of the ascendance of the new type of naval warfare dominated by carrier aviation. It was a battle in which Japanese and U.S. surface warships never even sighted each other, much less ever came within gunfire or torpedo range. But the climactic battle of the Solomons Campaign was Empress Augusta Bay, off Cape Torokina, Bougainville, a surface action in which aviation played only a minor role.

The commander of the U.S. task force at the Battle of Empress Augusta Bay was Rear Admiral Aaron Stanton “Tip” Merrill, whom Captain Wayne Hughes in his book, Fleet Tactics: Theory and Practice (Annapolis, MD: Naval Institute Press, 1986), regards as an equal with Captain Ar- leigh Burke. According to Captain Hughes, the two share the distinction of being tacticians par excellence in the U.S. Navy’s night fleet actions in the Solomons. “Thirty- one Knot” Burke became famous, rising to the position of Chief of Naval Operations and having a class of guided- missile destroyers named after him. Tip Merrill was much decorated, had a destroyer (DD-976) named after him in 1975, and Fletcher Pratt wrote a book about him in 1946.’ But Merrill is today lesser known. What were Merrill’s tactics, and how successful were they as the outnumbered U.S. forces clawed their way precariously up the Solomon Islands chain from Guadalcanal (August 1942) to Bougainville (November 1943)?

On 1 November 1943, Rear Admiral Theodore S. Wilkinson’s amphibious force began to land 14,000 U.S. Marines and Australian troops halfway up Bougainville’s weakly defended west coast at Cape Torokina, Empress Augusta Bay. Unwilling to allow the Allies this base to send fighter-escorted bombers against Rabaul, the Japanese sent a cruiser-destroyer force under Rear Admiral Sentaro Omori to attack the U.S. transports as they disembarked troops. The objective of Merrill’s Task Force 39 was to prevent this by interposing his ships between the Japanese offshore and the Allied transports and minelayers near the beach and off Cape Moltke.

Earlier in 1943, the variety of naval tasks—derailing the Tokyo Express, close- in support for shore bombardment of Japanese air bases and Allied landing operations, minelaying, etc.—had been conducted by two cruiser-destroyer divisions: Merrill’s Task Force 39 and Rear Admiral W. L. Ainsworth’s Task Force 38. But Task Force 38 was sent back to the United States, leaving Merrill’s force as the only cruiser- destroyer division in the Solomons. Given the shortage of U.S. warships available, Merrill had to accomplish the defense of the landing at Cape Torokina without allowing his own ships to be put out of action. His tactical plan involved keeping his cruisers beyond the range of Japanese Long Lance torpedos while maneuvering radically in formation by way of simultaneous ships’ movements timed to upset Japanese torpedo fire-control solutions. Speed variations were set at odd figures rather than even multiples of five, the usual estimate set on a torpedo director (e.g., a change from 24 to 27 knots, rather than from 25 to 30 knots).⁴

An even more significant element in Merrill’s tactical plan involved an innovation in the use of the eight destroyers in his task force, Destroyer Squadron 23, commanded by Captain Burke. Destroyers in both the U.S. and Japanese navies carried out many tasks without cruisers throughout the Solomons Campaign. But in 1942, the U.S. Navy counted cruisers as more valuable than destroyers because of their much greater gun power. Naval formations often placed the destroyers ahead and astern of the cruisers in one long, unwieldy column that the Japanese tactical commanders exploited with torpedoes, their decisive weapon for night actions. The Japanese had practiced night tactics built on short columns that, on detection of the enemy, would turn and fire as many torpedoes as possible in a massive salvo while never showing their beams to the enemy. The U.S. forces lost most of those night battles in the waters north of Guadalcanal, although because of a lack in intelligence they did not know how badly. One exception was the Battle of Savo Island, a debacle evident to all. When Burke arrived in early 1943, a lull followed the Japanese evacuation of Guadalcanal. Burke came to understand the reasons for failure, which had seemed inexplicable in light of U.S. radar advantage. He saw that a column was an untenable tactical formation, because it presented a column of targets so long it hardly could be missed. Since U.S. torpedoes, not gunfire, would be the decisive weapon, too, destroyers were critical. Burke drilled his destroyers in new tactics that would use radar advantage to close in two columns.

After arriving in the Solomons, Merrill studied the reports of earlier actions there and decided to follow Burke’s recommendation, giving his destroyers a more independent role. They would spring from each flank of the cruisers as “the untethered mad dogs charging in and inflicting the torpedo damage.”⁵ As Burke described the plan, it

was based on hitting the enemy with one sudden surprise after another. . . . One [destroyer] division would slip in close, under cover of darkness, launch torpedos and duck back out. When the torpedos hit, and the enemy started shooting at the retiring first division, the second half of the team would suddenly open up from a new direction. When the rattled enemy turned toward this new and unexpected attack, the first division would slam back in again.⁶

Meanwhile, the cruisers would open fire to draw attention, while staying at the outer limits of the Long Lance torpedoes. Only after the Japanese torpedoes had run their course would the cruisers again open fire. The destroyers would then get on a course parallel to the targets’ course and open fire after the cruisers. These tactics were designed to prevent what had happened at Tassafaronga in November 1942. There, Rear Admiral Tanaka, in command of eight destroyers, first noticed the guns of U.S. Task Force 67’s cruisers firing at him. He made the correct inference: if cruisers’ guns were firing, torpedoes from destroyers already were streaking toward him; so he immediately ordered a countermarch to the right and cleared the oncoming torpedoes.⁷

These tactical plans had to be put into effect in night battles, the only kind of surface actions the Japanese would fight in the Solomons. The Japanese Navy had trained extensively before the war for high-speed, limited area, night surface action. The U.S. Navy had no tactics for night battle at close quarters in the early months of the Solomons Campaign. Indeed, “U. S. tactical training proved counterproductive in the Solomons,” because Japanese tactics were almost the reverse of what the United States expected and had planned for before the war.⁸ As soon as he assumed command of Cruiser Division 12, Merrill set about to correct this shortcoming:

In mapping out our training program, emphasis was consistently put on night exercises. . . . [Our] modern ships were equipped with the last word in radar search and radar fire control, but the practical development of these complicated instruments and their adaptation to night fighting had been left to the sailors who were to use them. . . . They were full of bugs which hadn’t been eliminated, and instruments would frequently ‘go out’ with gunfire.⁹

Merrill also contributed to the innovation by which flag plots were transformed into the modern combat information center (CIC). From these innovations, Merrill developed a new task force doctrine.

The Battle of Empress Augusta Bay (which the Japanese call Gazere Wan or Gazelle Bay) was fought between 0227 and 0539 on 2 November 1943. The night, squally and “black as carbon,” imposed severe constraints on Merrill’s tactics. The four light cruisers and eight destroyers in Merrill’s task force never had fought as a unit before. Commander B. L. Austin’s four destroyers were operating under his command for the first time and had no previous experience in night action. Austin was not thoroughly familiar with Merrill’s battle tactics.¹⁰ Consequently, the tactics produced the following negative results.

First, although Merrill’s cruisers had radar fire-control, their frequent maneuvers at 30 knots degraded the effectiveness of their gunnery: an estimated four hits per thousand six-inch rounds fired.¹¹

Second, the tactics led to a melee. The three formations—Merrill’s cruisers and the two destroyer divisions— became separated, lost control and contact with each other, and ended up fighting three separate battles. For example, after Burke’s destroyers launched their torpedoes, they diverged into two groups of two ships each, not by plan, and it took an hour before they could be gathered together to turn full circle and return to their firing positions.

Third, both U.S. and Japanese ships’ damage was sustained as much by collisions as by enemy fire. Since sowing confusion among the Japanese ships was very much the essence of Merrill’s and Burke’s tactics, the resulting collisions were a positive result. Confusion also was a major reason the Japanese Navy turned and fled, thus giving Merrill his objective of protecting the beachhead. In each instance, the Japanese ships hit each other because they were concentrating on evading U.S. gunfire.

Fourth, some errors owed to the unfamiliarity of Austin’s Destroyer Division (DesDiv) 46 with Merrill’s tactics. At the beginning of the battle, Merrill ordered his cruisers to turn right together 180°. Merrill then ordered Austin’s destroyers to attack the southern flank of the Japanese force. The destroyer Foote (DD-511), the rear ship in Austin’s division, misunderstood the signal and got out of step with the formation. As she proceeded south and then west, the Foote became separated from her division. The Sendai’s salvo of eight torpedoes, intended to strike Merrill’s cruisers, missed them but hit the Foote. Austin, who also had misunderstood Merrill’s orders, was not in position to launch his torpedoes until after the U.S. cruisers had opened fire, thus missing the advantage of surprise.¹²

Fifth, because Austin’s DesDiv 46 had never deployed together, Austin’s flagship, the Spence (DD-512), and a second destroyer, the Thatcher (DD-514), were damaged slightly when the former sideswiped the latter as they tried to avoid the Foote.

Sixth, the U.S. ships had problems with friendly fire. Some of them flowed from the lack of experience in Task Force 39 as an operating unit. In one notable exchange that night, Burke’s division started straddling Austin’s division with shots. Austin radioed Burke, “For goodness sake, Arleigh, stop shooting at me.” Burke replied, “Okay, Count. I won’t shoot any more, but excuse the four salvos that are on the way!”¹³ In his after-action report for the light cruiser Montpelier (CL-57), under “Lessons Learned,” Captain R. G. Tobin noted that “Recognition remains a very critical matter. . . . [A] ship which is known (by its reduced speed) to be damaged so that its regular recognition equipment may be presumed to be out of commission presents a serious problem.”¹⁴

While Merrill’s tactics have been the focus here, tactics alone do not explain the U.S. victory at Empress Augusta Bay. The ships had surface and air search and fire control radar, whereas the Japanese still depended on optics and eyesight. Omori only rarely could see the U.S. ships that night; he was reduced to firing at their gun flashes.

Merrill’s “chronsolator” in flag plot gave him the advantage of a proto-CIC facility. Commenting after the battle, he said, “the evaluator must have an excellent grasp of the entire tactical situation in order to pass on this picture in words to the Captain on a darkened bridge. . . . The OTC [officer in tactical command] must see the graphic plot during night action even if forced by faulty design to fight his Force from the bowels of his flagship, and in this connection we learn the most important lesson of the battle.”

Omori’s ships also comprised a come-as-you-are force, hastily assembled without advantage of previous operations as a unit. Compounding this limitation, Omori ordered maneuvers that were too complicated for a pick-up force. The U.S. ships had much better intelligence. Aircraft snoopers sent Merrill three successive reports of the position, course, and speed of Omori’s force after it sortied from Simpson Harbor in Rabaul at 1500 on 1 November. This enabled Task Force 39 to steam at the lowest necessary speed toward the point of interception of the enemy. This reduced speed in turn lessened the chances that ships’ wakes could be discovered by Japanese reconnaissance planes. By contrast, Omori’s intelligence was very inaccurate. His conflicting aircraft reports only confused him. They told him there were battleships, heavy cruisers, and a much larger U.S. force than was actually there. Thus, technology, intelligence, and tactics together were essential factors that shaped the outcome.

In commenting about the comparatively minor role air power played at Empress Augusta Bay, Merrill put it this way after the battle:

We sailors should all have a clear appreciation of the limitations of aircraft as well as their virtues. When Admiral Wilkinson requested that T.F. 39 take position between St. George’s Channel and Empress Augusta Bay in the event the retiring enemy Task Force reverse its course, “Air Solomons” replied that if this Jap Task Force reversed its course the air would destroy it before it could reach Empress Augusta Bay. Only the reconnaissance planes which made the two excellent contact reports were in evidence on this black and squally night. Had Admiral [William] Halsey and Admiral Wilkinson failed to appreciate aircraft limitations the enemy Task Force might have destroyed our transports and mine laying detachment and shelled our troops and supplies which were freshly landed on the beaches of Empress Augusta Bay.¹⁵

Despite these tactical and other flaws, Merrill had achieved a great victory. By blocking the entrance to Empress Augusta Bay, he prevented the destruction of the Allied amphibious force landing on the beach. Omori never got closer than 35 miles of the U.S. transports at Cape Torokina. Merrill’s plan required him to push the Japanese ships to the west, away from the Cape, both to give him more sea room for maneuvering and to allow any of his ships that were damaged to retire on the disengaged side.

Merrill had fought a night action against heavier ships. One Japanese light cruiser, the Sendai, and one destroyer, the Hatsukaze, were sunk; two destroyers, the Samidare and Shiratsuyu, were damaged in a collision with each other and had to pull away from the battle early; the heavy cruiser Myoko was dented in a collision; and the other heavy cruiser, the Haguro, was damaged severely. All this was accomplished while only one of Merrill’s ships, the Foote, incurred any torpedo damage.¹⁶

Although Merrill’s destroyers’ tactics left something to be desired that night, his own cruisers kept formation, and he “led his ships through an elaborate sequence of course changes, stepping and side-stepping, turning and weaving, to avoid giving a target for the Long Lances.” Twenty-two course changes were ordered between 0228 and 0534, an average of one every eight minutes. These turns were made by the four cruisers together, and their frequency reveals the intensity of the maneuvers. Merrill’s “cruiser captains followed him with admirable skill, despite the smoke and din of the battle.”¹⁷ As a result, Omori was forced to fight on Merrill’s terms—at 20,000 yards, where neither his Long Lance torpedoes nor his optics were usable.¹⁸ As a result, although the U.S. cruisers repeatedly were straddled by Japanese salvos, they sustained only minor hits.

Like the Japanese ships, Merrill’s cruisers’ six-inch guns also achieved few hits. They were firing at the outer limits of effective range, and their maneuvers degraded their fire control. Probably more important is the fact that radar fire control was accurate in range but not very accurate in deflection. This meant the Japanese were inundated by a hail of rapid-fire six-inch shells, which must have been frightening in the extreme. That, rather than the destructiveness of the hits, was the intended role of the cruisers in Merrill’s battle plan, and it was executed flawlessly.¹⁹

Merrill’s cruisers also maneuvered by turning away from the Japanese and making chemical and funnel smoke that blocked light from Japanese star shells. “Behind this screen and despite the continuous roar of our gunfire, [Merrill] ordered evasive maneuvers over the voice radio that were followed by the cruisers with dispatch and . . . precision.”²⁰ Omori, attempting to soften his failure, claimed he mistook the smoke for destruction of U.S. ships and therefore turned away and soon ordered a general retirement.²¹ This conveniently sidesteps the fact that he had totally failed to accomplish his original mission of destroying the transports and shelling the Allied landing force before it could dig in at Cape Torokina.

Thus, in “Stygian darkness,” Merrill’s physically exhausted crews “had fought a hard battle that in its complexities was the equal of any naval engagement the United States Navy had ever fought.”²²