by Mark Stille
Beginning in December 1941, another class of light cruisers, named after the lead ship Atlanta, entered service. These ships were originally designed as scout cruisers and were heavily armed with eight twin 5in. mounts and torpedoes. This armament made them ideally suited as antiaircraft platforms, but their light armor made them ill-suited for surface combat. Four ships of the class were active during the Guadalcanal campaign; two of these were engaged in surface combat and both were sunk.
Heavy cruiser Northampton attempting to tow the crippled carrier Hornet during the battle of Santa Cruz on October 26, 1942. The cruiser spent most of the campaign on carrier screening duty, but was committed in November to surface combat, and was sunk by torpedoes at the battle of Tassafaronga by Japanese destroyers. (Naval History and Heritage Command, 80-G-33897)
Destroyers
The interwar naval treaties also impacted on American destroyer designs and numbers. The London Naval Treaty of 1930 placed limits on overall destroyer construction and restricted the maximum size of destroyers. Just as for cruiser construction, designers faced difficult choices with regard to placing heavier armament, greater endurance, and superior sea-keeping qualities on larger destroyers, or producing a greater number of smaller destroyers where compromises had to be made. Generally, American designers favored larger designs with a heavy gun armament.
The US Navy saw destroyers as more than just torpedo boats. They also needed a heavy gun armament to defeat Japanese destroyer attacks against the battle line and to contribute to fleet air defense against Japanese aircraft. Torpedo armament was also an important design consideration, since this was the only way a destroyer could inflict serious damage on enemy heavy units. A typical prewar American destroyer was the 18-unit Mahan class, all of which saw action in the Pacific. These ships had a standard displacement of 1,500 tons and carried five 5in. guns and 12 torpedo tubes. Late in the campaign, the first American destroyer class designed totally free of treaty restrictions reached the Solomons. This was the Fletcher class, which presented a good mix of speed (38 knots), and offensive and defensive capabilities. Each ship carried five 5in. guns, and ten torpedo tubes. Like all other American destroyers, the Fletchers carried radar.
The primary weapon of the destroyer in surface combat was its torpedo. American destroyers were severely handicapped by the performance of their inferior torpedoes, and during the Guadalcanal campaign these problems were not even recognized, much less addressed. The standard American destroyer torpedo was the Mark 15. When compared with the standard Japanese torpedo, it was markedly inferior. Added to this, the Mark 15 was unreliable, since it suffered from faulty magnetic fuses and a tendency to run well below its set depth. The result was that the main weapon of American destroyers was defective throughout the campaign. In turn, this reinforced the prevailing view that the gun, not the torpedo, was the US Navy’s primary weapon of decision.
Radar
The biggest advantage possessed by the Americans in the night surface battles fought during the campaign was radar. It had significant impact on a number of battles. However, at the start of the campaign American radars were fairly primitive and commanders did not fully understand their use. The first radar in widespread use was the SC-2. This was fitted aboard both destroyers and cruisers and had an approximate range, under ideal conditions, of six miles against a destroyer-sized target. The next set introduced was the SG radar, which was designed as a surface search radar. It was the first surface search set to incorporate a plan position indicator (PPI) display. The PPI provided a radar “map” of the area, making it much easier to use and interpret. Under ideal conditions, the SG radar could detect a destroyer-sized target at 15 miles.
In addition to providing detection of an approaching enemy at extended ranges, the US Navy was also developing tactics to use radar to direct gunnery. This had great potential to increase the effectiveness of night gunnery since visibility was no longer a factor. However, radar was not infallible. It was often unable to break out different targets located close together, maneuvering rapidly, or located close to land. Even more significant was the inability of radar to tell the difference between enemy ships and shell splashes around them after they had been taken under fire. This led to the phenomenon known as “chasing splashes” since shell splashes in front of the target were often the strongest returns, which prompted the radar operator to target them. This allowed the real target to move away, only to be picked up again as a new target after the operator stopped targeting his own splashes.
The Fletcher class was the largest class of fleet destroyers ever built. With their combination of firepower, speed and advanced electronics, these ships became deadly threats to the UN. (Naval History and Heritage Command, NH-53916)
Light cmiser Juneau in June 1942. The Atlanta-class unit had a short career from February until November 1942. She was sunk by a submarine torpedo immediately following the Second Naval Battle of Guadalcanal and all but ten of her crew of 693 died. (Naval History and Heritage Command, 19-N-31263)
By November 1942, the first ships of the new Fletcher class began to reach the South Pacific. This is the lead ship Fletcher, pictured in July 1942. This view shows the ship’s five 5in. guns and two quintuple torpedo launchers. Perhaps more importantly, the ship had a full radar suit including the modern SG surface search radar (the small curved device on the mainmast). (Naval History and Heritage Command, 19-N-31243)
US Navy nightfighting doctrine
Going into the Guadalcanal campaign, American nightfighting doctrine was inadequate. This was in spite of the fact that it was recognized that part of any decisive surface engagement would be fought at night and that night tactics had been under development since 1932. American night tactics stressed gun combat and featured a flawed torpedo doctrine. This meant that commanders during the Guadalcanal campaign devised tactics geared to cruiser gunnery while ignoring the offensive potential of destroyers.
This imbalance stemmed from an emphasis on so-called “Major Tactics” which were devised and practiced as part of the expected decisive engagement between opposing battle lines. “Minor Tactics” for light units were not seen as important. Cruisers and destroyers were well drilled in forcing a hole in the enemy screen to allow destroyers to attack enemy battleships at close range with torpedoes. Destroyer gunfire was to be directed at the enemy battleship’s bridge and superstructure to reduce its defensive fire. This tactic reinforced the notion that only battleships were worthy of torpedo attack and that the targets would be slow and well illuminated. This had little resemblance to actual conditions off Guadalcanal.
Though American torpedo tactics and torpedoes were deficient, American gunnery was more effective. Early in the Guadalcanal campaign, the firepower of the heavy cruiser with its heavier 8in. shell was preferred since it had the penetrative power to defeat Japanese heavy cruisers. The fast-firing 6in. guns on the light cruisers were preferred against destroyers because of their volume of fire. Using radar, American admirals were convinced that they could engage a target at 10,000 yards and destroy it before it could fire torpedoes. Unfortunately for the Americans, this was less than the effective range of the Japanese Type 93 torpedo. The Americans remained ignorant of the true capabilities of the Type 93 throughout the campaign.
OPPOSING PLANS
JAPANESE PLANS
Following Midway, the Japanese did not expect any American offensive moves in the Pacific. However, King’s limited counteroffensive caught the Japanese totally by surprise. As will be recounted shortly, the American landing on August 7 did prompt a sharp response by the local Japanese commander, but to throw the Americans off the island would require a unified plan by both the Imperial Army and Navy. Since this was the first Allied attempt to regain lost territory, it was a test of Japan’s basic war strategy of repelling any Allied assault on the Japanese perimeter, and making the cost of any failed Allied offensive so prohibitive that the Americans would eventually seek a negotiated peace, leaving Japan with her
conquests.
The first meeting of the Army and Navy Sections of the Imperial General Headquarters took place on August 7. Even at this earliest meeting the pattern of underestimating the strength of the American offensive was apparent. The first assessment by the Japanese was that the attack was only a reconnaissance in force. Upon receiving reports from the Japanese air attacks on August 7 of 30 transports present off Guadalcanal, wiser heads prevailed and the American move was assessed to be a divisional-sized attack. On August 10, the heads of the Naval and Army General Staffs agreed to a plan to deal with the incursion. Ongoing operations to occupy Port Moresby on New Guinea would still be given priority, but 17th Army under General Hyakutake Harukichi was assigned the mission to retake Guadalcanal and Tulagi. For this, he was assigned an infantry brigade and two regiments. Of these, only one regiment, located at Guam, was immediately available.
Henderson Field in August 1942. Note the aircraft on the left and the many bomb and shell craters all around. Possession of the airfield was the key to victory in the Guadalcanal campaign. (Naval History and Heritage Command, 80-G-16312)
Within days of this plan, the estimate of the American garrison on Guadalcanal had been drastically revised down. This confirmed a pattern of Japanese bending intelligence to preconceived notions of American intentions and capabilities and set up a cycle of piecemeal commitment. The immediate result of this combination of overconfidence and the desire to dislodge the Marines as quickly as possible resulted in the decision to attack with a single battalion (the Ichiki detachment of 917 men) as soon as possible. Since the actual size of the Marine garrison was some 10,000 men, this attack resulted in failure.
On August 20, the first American aircraft arrived on Guadalcanal. Since victory would ultimately be decided by which side could reinforce the island the fastest, the presence of the American airfield made the Japanese task much more difficult. The Americans now dominated the waters around the island during the day, which made the use of transports to bring troops to the island impossible. This was confirmed during the battle of the Eastern Solomons when a small Japanese convoy was turned back by airpower. Over time, it proved impossible for the Japanese to suppress the airfield using bombers from Rabaul or aircraft from carriers.
In mid-September, a Japanese attempt to take the airfield with a brigade failed. This failure seemed to galvanize the Japanese into making a real effort to bring decisive forces to bear. The Naval General Staff saw this as the setting for a decisive battle with the Americans, though this sense of urgency never seems to have filled Yamamoto with the determination to commit all his forces. The recapture of Guadalcanal was now given priority over the New Guinea operation and two divisions were allocated to 17th Army. With these reinforcements, a new attack was planned for about October 20.
These reinforcements were moved to Guadalcanal by a combination of small barges, nightly destroyer runs, and a convoy of transports, which arrived on the island after the airfield was temporarily neutralized by a Japanese battleship bombardment. Yamamoto now made supporting the recapture of the island the primary mission of the Combined Fleet, rather than the destruction of the American fleet. However, when the Japanese ground attack was launched, it again failed.
This set up the decisive phase of the campaign, when the Japanese planned to send a large convoy to the island. To cover this convoy, Yamamoto stepped up air attacks against the airfield and planned to conduct another battleship bombardment to knock out the airfield. The failure of this effort in November was the turning point in the campaign.
An American destroyer sails up what would soon be known as Iron Bottom Sound on August 7,1942. Savo Island is straight ahead in the distance and Cape Esperance on Guadalcanal is on the left. (Naval History and Heritage Command, 80-G-13539)
UNITED STATES PLANS
Compared with the Japanese plans, the Americans had a simple set of tasks – occupy the island, keep the airfield open, and react to major Japanese reinforcement operations. As long as the airfield was able to operate aircraft, the Americans dominated the waters around Guadalcanal during the day. This made movement of reinforcements to the island by transports all but impossible.
Since the Japanese were unable to operate near Guadalcanal during the day, they were forced to rely on destroyers to run troops and supplies into the island at night. This was an inefficient means of transport and did not allow the movement of heavy supporting equipment. The Americans were slow to respond to the constant Japanese movement of troops and supplies at night. After the battle of Savo Island, the Japanese were in undisputed control of the waters around Guadalcanal after dark. It was not until mid-October that Ghormley took measures to stop the Tokyo Express, which resulted in the battle of Cape Esperance.
When the Japanese used battleships to neutralize the airfield temporarily in October, the Americans had to take measures to prevent another such bombardment. This was the reason behind the decisive naval battles in November when the Americans threw task forces against Japanese battleship bombardment forces on two occasions.
THE NAVAL CAMPAIGN FOR GUADALCANAL
THE BATTLE OF SAVO ISLAND
The longest naval campaign of the Pacific War began on August 7, 1942 when the United States launched its first offensive of the World War II. The target of the American move was the uncompleted Japanese airfield on the island of Guadalcanal on the southern Solomon Islands. The Marines landed five battalions on Guadalcanal and, against weak resistance, succeeded in capturing the airfield on the afternoon of August 8.
The surprised Japanese garrison on the island was composed of construction troops and was unable to impede the American advance to the airfield. However, Japanese forces in the Rabaul area were quick to respond. The first reaction took the form of an air raid with 27 G4M1 bombers escorted by 18 A6M2 Model 21 fighters. A group of nine D3A dive-bombers was also dispatched to make the 565-mile trip to Guadalcanal, even though these lacked the range to return to Rabaul. One of the fighters turned back, leaving 53 aircraft to attack the naval units off the American beachhead. The attack was an expensive failure with five bombers, two Zeros and all nine dive-bombers being lost in exchange for a single bomb hit on an American destroyer. The defending American fighters suffered heavily, losing nine aircraft, but the Japanese goal of disrupting the landing was unachieved.
An American light tank being unloaded from an attack transport ship on August 7, 1942. The landing on Guadalcanal was unopposed and the island’s airfield was quickly captured. (Naval History and Heritage Command, 80-G-10973)
The next day, August 8, the Japanese air assault continued. This time, 27 bombers loaded with torpedoes escorted by 15 fighters headed south to Guadalcanal. Unable to find their primary target, the American carrier force, they turned to hit the beachhead. Twenty-three bombers actually conducted the attack. Against defending American fighters and heavy antiaircraft fire, 18 of the bombers were destroyed, along with two fighters. In exchange, one destroyer was hit by a torpedo (the vessel eventually sank on its return trip to the United States for repairs), and one bomber crashed into a transport, which caused a serious fire, forcing the ship to be scuttled.
On August 8, the Japanese sent 27 G4M1 bombers with torpedoes to attack the invasion shipping of Guadalcanal. Twenty-three of the bombers attacked, and suffered heavy losses. This shows part of that event with the transport President Jackson in the foreground with a cruiser and low-hanging antiaircraft bursts in the background. The attack damaged a destroyer and a transport, neither of which survived. (Naval History and Heritage Command, 80-G-K-385)
The ineffective air attacks were not the only reactions planned by the Japanese. As soon as Mikawa learned of the American landing on Guadalcanal, he resolved to mount a night attack with whatever surface units were available. By 0830hrs on August 7, he ordered his five available heavy cruisers to join at Simpson Harbor at Rabaul. These included his flagship, Chokai, and the four ships of Sentai 6 which were anchored at Kavieng out of the range of Allied a
ir attack. Rounding out Mikawa’s force were the two old light cruisers of Sentai 18 and a single available, and again old, destroyer. Aside from the four ships of Sentai 6, none of these ships had ever worked together. By 1430hrs, the scratch force had received its orders and, under Mikawa’s personal command, sailed out of Simpson Harbor.
As Mikawa headed south, he had little idea of the strength of the American forces around Guadalcanal, and, more importantly, the location of the American carrier force. Long-range aircraft from Rabaul were unable to find the American carriers, but Mikawa did eventually receive information about the location and numbers of Allied ships in the waters off Guadalcanal. A report from one of his cruiser floatplanes indicated that the American force was larger then his own, but Mikawa was sure that the Japanese edge in night tactics would even the odds. At 1300hrs he headed south from his position east of Bougainville Island into the body of water inside the Solomon Islands that would soon be known as “the Slot.” His intention was to strike at the American landing force during the night of August 8–9. The Japanese force would pass to the south of Savo Island and enter the waters off Guadalcanal which would soon be known as Iron Bottom Sound after the number of ships which would come to rest there. Upon entering Iron Bottom Sound, the Japanese force would first engage the enemy units located off Guadalcanal before swinging to the north to engage the enemy force off Tulagi. Of note: Mikawa’s pre-battle instructions made no mention of attacking the transport fleet.