On September 12 a three-column Japanese attack on the perimeter around Henderson Field was repulsed with heavy losses, notably in a fight involving one column assaulting U.S. Marine Raiders on “Bloody Ridge” (or “Edson’s Ridge”).
Action on Bloody Ridge
On 12 September the Raider-Parachute Battalion attempted to patrol south along the ridge but met enemy rifle fire. The battalion dug in for the night on the southernmost knoll. During the night of 12-13 September there was continuous firing along the ridge. That the enemy had penetrated to the jungles around the ridge was obvious, but the dense growth and the blackness of the night limited visibility from Bloody Ridge. At one time during the night some Japanese actually broke through the sketchy positions of the Raider-Parachute Battalion, but apparently failed to realize it for they made no effort to exploit their advantage.
The Raider-Parachute Battalion attempted a further advance after daybreak on 13 September, but failed to gain. Exhausted by fighting in the heat, it halted in the afternoon to establish a slightly stronger, higher position about 250 yards north of its bivouac of 12-13 August. On the right the raiders had made a tenuous connection with the pioneers, but the left flank was open. The 2d Battalion of the 5th Marines, then in division reserve, moved to the south edge of the airfield on the afternoon of 13 September to effect the relief of the Raider-Parachute Battalion the next morning. One battery of the 5th Battalion, 11th Marines (105-mm. howitzers), had been assigned to provide direct support to the ridge area. Men from the 11th Marines Special Weapons Battery maintained an observation post on the ridge. In the afternoon the battery had registered on areas in the south but accurate plotting was impossible because there were no reliable maps.
On the ridge itself two companies of parachutists were holding the eastern spur of the center knoll, with their left flank uncovered; B Company of the Raiders held the center of the knoll on the parachutists’ right. Posted on the right between the ridge and the Lunga River was A Company, and C Company was the battalion reserve. During the last hours of daylight on 13 September the troops dug in and extended their fields of fire.
Enemy aircraft attacked Lunga Point repeatedly during the day. American fighter planes forced one wave of bombers to turn back, but at 1020, 1320, and 1750 Japanese bombers protected by fighter escort came over to attack Henderson Field and positions adjacent to the ridge.
Shortly after nightfall on 13 September rocket flares over Bloody Ridge announced the opening of an attack by at least two battalions of the Kawaguchi Force. Without any artillery preparation, the main body attacked north against the center of the ridge while one force cut through the jungle west of the ridge and isolated the right platoon of B Company of the raiders and cut off A Company. Though surrounded, the platoon from B Company fought its way about 250 yards to the rear to join the battalion reserve on the northernmost knoll. The Japanese exploited the gap between the raider companies and the pioneer companies by moving strong parties in, while at other points small groups infiltrated through to cut telephone wires. B Company of the raiders, in danger of envelopment, refused its right flank along the western slopes of the ridge.
The registered battery of the 5th Battalion, 11th Marines, opened fire on the enemy at 2100 joined shortly thereafter by a second and then a third battery. All batteries fired over the heads of the marines on the ridge. As the enemy attack grew in intensity the 5th Battalion began firing heavy concentrations. Communications between the fire direction center and the forward observers were broken for about two hours, but the artillery continued to fire without observation.
While continuing the attack against B Company on the center of the ridge, the Japanese put heavy mortar fire on the parachutists’ positions on B Company’s left. At 2230, shouting loudly, the Japanese infantry stormed the parachutists’ lines and drove them back off their eastern spur. This exposed B Company to attack from three sides. Colonel Edson, commanding the Raider-Parachute Battalion, decided to withdraw B Company from its dangerous position and to rally his forces on the northern knoll of Bloody Ridge, the battalion reserve line. Using C Company of the raiders as a nucleus, Colonel Edson and Maj. Kenneth Bailey, the executive officer, successfully re-established the lines on the last knoll in front of Henderson Field and the division command post.
The Japanese, continuing their attacks, advanced uphill against artillery, mortar, machine-gun, and rifle fire and grenades. As at the Ilu, these assaults failed to break the last lines. Kawaguchi’s forces attacked Bloody Ridge about twelve times during the night. The direction and objective of every attack was preceded by a rocket flare, each of which served as a point of reference for the fire of the 5th Battalion, 11th Marines. From 2100, 13 September, until dawn the next day, the 105-mm. howitzer batteries fired 1,992 rounds in support of the Raider-Parachute Battalion at ranges as short as 1,600 yards. They sometimes put shells within 200 yards of the front lines, which was generally considered to be an unusually short distance in the early days of the war. By 0230 Colonel Edson had concluded that his troops could hold out, although they were still under attack. As morning drew near the vigor of the Japanese assaults declined.
By dawn of 14 September the Raider-Parachute Battalion was still holding the last knoll on Bloody Ridge. The Japanese attacks had ceased. After aircraft took off from Henderson Field and drove the remaining enemy from Bloody Ridge, the Kawaguchi Force began to retreat.
Action on the Flanks
While the main enemy body was attacking Bloody Ridge, a second unit of the Kawaguchi Force had attacked west about midnight against the right flank of the 3d Battalion, 1st Marines, on the Ilu. Here the line lay along the edge of the jungle in front of a 700-yard-deep flat, grassy plain to the east. The front was wired in; fields of fire had been prepared by burning and trampling the grass. The right end of the line was without flank protection and thus was open to envelopment.
About two companies of Japanese attacked against the front of the right flank unit, but failed to penetrate the line. A fire fight developed which lasted throughout the night, but the 1st Marines’ positions were never seriously endangered.
During the day division headquarters, believing that the force still facing the 1st Marines on the east flank was composed of one infantry battalion supported by artillery, sent six light tanks across the plain to destroy the enemy. When they made repeated sorties over the same routes of approach, three tanks were hit by antitank gunfire and one overturned in a creek. The Japanese did not attack the 1st Marines again but engaged the right flank of the east line with desultory fire until 16 September.
A third Japanese force, probably under Colonel Oka’s command, struck on the afternoon of 14 September in the west sector. Part of the 3d Battalion of the 5th Marines was holding the sector from the coast inland to a ridge which commanded the coastal road. The Japanese, debouching from the jungles, struck suddenly at the ridge but failed to take it and were driven back down the slopes by infantry counterattacks and artillery fire.
The Cost The exact composition of the three Japanese attacking forces is not clear. The 1st and 3d Battalions of the 124th Infantry and the 2d Battalion of the 4th Infantry probably delivered the assault against Bloody Ridge while the Ichiki Force rear echelon may have attacked the 1st Marines. The 2d Battalion, 124th Infantry, probably delivered the weak attack against the 5th Marines on 14 September.
Marine casualties on Bloody Ridge were about 20 percent of the total force engaged. Thirty-one were killed, 103 wounded, and 9 missing. The Japanese casualties were much higher. Of an estimated 2,000 who attacked Bloody Ridge, about 600 were killed on the ridge itself. After its repulse, the Kawaguchi Force began to retreat, carrying its wounded in litters. The Japanese had entered the action with only a few days’ rations, and these seem to have been quickly exhausted. About 400 men of the 2d Battalion, 28th Infantry (Ichiki’s rear echelon) made their way east to Koli Point. Some troops of the 2d Battalion, 4th Infantry, were also reported to have gone to Koli Point. The remainder of the Kawaguchi Force retreated to the west by cutting a trail around the rough southern slopes of Mount Austen to Kokumbona. Many of the wounded died, and the weakened survivors buried dead soldiers, heavy equipment, and artillery pieces along the way. The journey took over a week. The Japanese reported that 633 men were killed in action, and 505 wounded.
That the Kawaguchi Force could offer no immediate threat to Henderson Field was indicated in the week following the Bloody Ridge action. Marine patrols fought a series of successful engagements with Japanese units along the upper reaches of the Lunge River. They found stocks of the equipment, ammunition, small arms, and guns of two field artillery batteries which the Kawaguchi Force had abandoned. The second and more formidable threat to Henderson Field had been successfully averted.
Aftermath
On September 18, Imperial General Headquarters decided to give Guadalcanal highest priority in the South Pacific. Henderson Field was identified as the main target for renewed attacks by Japanese Army reinforcements to be sent in from all over the Greater East Asian Co-Prosperity Sphere. The Allies also poured in reinforcements, bringing in a total of 123,000 men by the end of December. The Japanese brought their strength up to 92,000 over the same period. Protecting or attacking transport of arriving troops and supplies led to several naval battles in the waters around Guadalcanal. Each side also sent submarines and bombers to prowl “The Slot.” The IJN landed the Sendai Division near the Matanikau in October, while the USN landed the Americal Division on Lunga. The IJN carried out dangerous night runs down “The Slot” with cruisers and destroyers. At the end of the run they bombarded Henderson Field and marine trenches with naval guns, but always pulled out before dawn exposed them to retaliatory air attack. Reinforcements arrived via what Japanese called the “Rat Express” (on destroyers) or “Ant Freight” (on motor torpedo boats). The Allied press dubbed the Japanese supply system the “Tokyo Express.” On October 11–12 elements of the opposing fleets fought the Battle of Cape Esperance. On the 14th, two Japanese battleships bombarded Henderson, followed by IJN cruiser attacks on subsequent nights.
