[USMCRET6391]

Tasimboko

As August progressed it became clear that the Japanese were focusing their effort in the Solomons on regaining the vital airfield on Guadalcanal. The enemy poured fresh troops onto the island via the "Tokyo Express," a shuttle of ships and barges coming down the "the Slot" each night. The 1st Marines destroyed the newly landed Ichiki Detachment along the Tenaru River on 21 August, but the understrength Marine division had too few troops to secure the entire perimeter. To bolster his force, General Vandegrift brought the raiders over from Tulagi at the end of August and switched the parachutists a few days later. The two battalions went into reserve in a coconut grove near Lunga Point. During this period Major Miller took ill and went into the field hospital, as did other parachutists. The shrinking battalion, temporarily commanded by a captain and down to less than 300 effectives, was so depleted in numbers and senior leadership that Vandegrift decided to attach them to Edson's 1st Raider Battalion. The combined unit roughly equalled the size of a standard infantry battalion, though it still lacked the heavy firepower.

Following the arrival of the first aviation reinforcements on 20 August, the division made use of its daytime control of the skies to launch a number of seaborne operations. Near the end of the month, a battalion of the 5th Marines conducted an amphibious spoiling attack on Japanese forces to the west of the perimeter, but inflicted little damage due to a lack of aggressive leadership. Two companies of raiders found no enemy after scouring Savo Island on 4 September, while a mixup in communications scrubbed a similar foray scheduled the next day for Cape Esperance. By 6 September, Japanese naval activity and native scouting reports indicated that the enemy was concentrating fresh troops near the village of Tasimboko, located on the coast several miles east of the Marine lines.

Edson and Lieutenant Colonel Gerald C. Thomas, the division operations officer, hatched a plan to raid this eastern terminus of the Tokyo Express on 8 September. Intelligence initially placed two or three hundred Japanese at Tasimboko with their defenses located west of the village and facing toward Henderson Field. Edson planned to land to the east of the village and attack them from the rear. The available shipping consisted of two destroyer transports (APDs) and two small, converted tuna boats, so the raider commander divided his force into two waves. The raider rifle companies would embark on the evening of 7 September and land just prior to dawn, then the tiny fleet would shuttle back to the perimeter to pick up the weapons company and the parachutists. Since the APDs were needed for other missions, the Marine force would have to complete its work and reembark the same day. (The Navy had already lost three of the original six APDs in the Guadalcanal campaign.)

On the evening of 7 September, native scouts brought news that the enemy force at Tasimboko had swelled to several thousand. Division planners discounted these reports, believing that they were greatly exaggerated or referred to remnants of previously defeated formations. When the raiders landed at 0520 on the 8th, they immediately realized that the natives had provided accurate information. Not far from the beach, Marines discovered endless rows of neatly placed life preservers, a large number of foxholes, and several unattended 37mm antitank guns. Luckily for Edson's outfit, Major General Kiyotake Kawaguchi and his brigade of more than 3,000 men already had departed into the interior. Only a rear guard of 300 soldiers remained behind to secure the Japanese base at Tasimboko, but even that small force was nearly as large as the first wave of raiders.

Company D of the raiders (little more than a platoon in strength) remained at the landing beach as rear security while the other companies moved west toward Tasimboko. The raiders soon ran into stubborn resistance, with the Japanese firing artillery over open sights directly at the advancing Marines. Edson sent one company wide to the left to flank the defenders. As the action developed, the APDs Manley and McKean returned to Kukum Beach at 0755 and the Parachute Battalion (less Company C) debarked within 25 minutes. The 208 parachutists joined Company D ashore by 1130 and went into defensive positions adjacent to them. Edson, fearing that he might be moving into a Japanese trap, already had radioed division twice and asked for reinforcements, to include another landing to the west of Tasimboko in what was now the enemy rear. In reply, division ordered the raiders and parachutists to withdraw. Edson persisted, however, and Japanese resistance melted away about noon. The raider assault echelon entered the village and discovered a stockpile of food, ammunition, and weapons ranging up to 75mm artillery pieces. The raider and parachute rear guard closed up on the main force and the Marines set about destroying the enemy supply base. Three hours later the combined unit began to reembark and all were back in the division perimeter by nightfall.

The raid was a minor tactical victory with major operational impact on the Guadalcanal campaign. At a cost of two killed and six wounded, the Marines had killed 27 Japanese. The enemy suffered more grievously in terms of lost firepower. logistics, and communication. Intelligence gathered at the scene also revealed some details about the coming Japanese offensive. These latter facts would allow the 1st Marine Division to fight off one of the most serious challenges to its tenuous hold on Henderson Field.