|Combined Guadalcanal Campaign|
|Part 4: Assault on Edson's Ridge|
|by Patrick Graham|
After the unsuccessful Battle on the Ilu River, it became clear to the Japanese high command of the seriousness of the Guadalcanal invasion and what it could mean for their Pacific strategy. More over, it became apparent as to the degree the marines had entrenched themselves on the island. The small force that Colonel Ichiki had led against the marines at Ilu failed to make a dent in the American perimeter and was wiped out in turn. A massive build-up of soldiers and equipment would be necessary to continue the offensive on Guadalcanal.
The Battle of the Eastern Solomons, failed to strip Guadalcanal operations of their air cover. Moreover, the transports that were headed for Guadalcanal with the escorting naval group were damaged and turned back, unable to deliver the over 1,000 troops on board. Henderson Field was still in full operation, and despite the damage done to the Enterprise there were still a good number of aircraft in the area to counter any Japanese incursions and ressuply efforts. New troops of the 35th Infantry Brigade, commanded by Lieutenant-General Kiyotaki Kawaguchi would be delivered via the Tokyo-Express, a convoy of destroyers that traveled to Guadalcanal from the Shortland Islands under the cover of night. It would take several destroyer runs, each of varying degrees of success with some incurring daytime attacks when they were to slow or low on fuel, between August 28th and September 4th.
On September 7th, Kawagichi divided his forces, sending the remainder of the former Ichiki regiment to attack from the east of the marine perimeter, while his force struck from the west, up along the spine of a ridge that led to Henderson Airfield. A raid on the Japanese base at Taivu Point led by Lieutenant-Colonel Edson, who would defend the ridge that bears his name, successfully destroyed most of the Japanese supplies. Intellegence secured during the raid indicated a massive attack would be coming from the southwest of the perimeter along a ridge that ran alongside the Lunga River.
Edson’s 850 raider Marines were tasked with defending the ridge along with a detachment of the 1st Marine Parachute Battalion. However, General Vandergrift was not convinced an attack would come from that direction and refused to reinforce the ridge further at the cost of the defenses along the coast. The southern edge of the ridge, Hill 80, was surrounded by Jungle that masked the movements of any enemy soldiers. Just after 2100 hours on September 12th, a battalion under the command of Major Kukisho struck the flank anchored on the Lunga River. However, without all of the Japanese units in place to support Kukisho, the attack was called off. Kukisho had forced the marines by the river back to the ridge itself, folding the American line on itself.
The Marines were certain of a renewed attack on the following night and the short fighting that had just occurred already cost them valuable ground. Marine counter-attacks against the Kukisho’s forces along the Lunga river failed to dislodge them. Edson made the decision to pull his entire line back from Hill 80 to Hill 123, which was, of course, higher and overlooked a sizable gap that any attacking force would have to cross once they crested Hill 80. After 2000 hours on September 13th, Kawaguchi unleashed his regiments anew, and the proceeded to make a three pronged attack against Edson’s positions along the ridge, which was now bending into a horseshoe shape from the weight of the attacks.
Combined Guadacanal Campaign Pt. 24: Assault on Edson's Ridge.
At 2030 hours, on September 13th, 1942, Japanese forces under the command of Lieutenant-General Kawaguchi strike at Marines defending Hill 123 along Edson’s Ridge on Guadalcanal. The Japanese forces must clear the Hill in order to open the way for a further attack against Henderson Field itself. American Marines must defeat each prong of the attack in turn using Marine raiders and paratroopers.
The battle for Edson’s ridge culminated in an assault on Hill 123 on the second day of the battle. Snipers had infiltrated behind and around the lines of the Marines and plagued them with fire for the entire battle. Despite the limited success of sniper teams, the bulk of the assault on the ridge came in the form of frontal attacks on prepared positions using rifle-fire and bayonet charges backed up my light mortars and machine-gun fire. However, each of these attacks came upon well entrenched positions with machine guns and artillery set-up and in prefixed firing arcs for such an assault. 105mm artillery combined with mortar and machine gun fire single handedly stopped that attack on the hill’s left flank dead.
The battle had also shown Japanese tactics to largely be insufficient in dealing with defensive positions. Repeated frontal charges against dug-in machine gun nests only waste lives. The procedure for flanking and assaulting fixed positions on a tactical level was one not yet refined by the Japanese. Their martial prowess could only take them so far, and it was clear the marines were not to be defeated simply on the end of the bayonet. Moreover, there was a persistent refusal to acknowledge the depth of the American forces on Guadalcanal. Prior to the attack, Kawaguchi believed there to be only 2,000 marines to his 5,000 when in fact there were 5 times that number on Guadalcanal.
The loss on the ridge and the need for even further support to successfully prosecute a campaign on Guadalcanal, began to tell on the Japanese. Forces would have to be diverted from other theaters, at the expense of other ongoing campaigns in order to maintain the fight on Guadalcanal. Already, manpower was short and supplies were stretched thin. This certainly was not helped by the continued underestimation of the American presence on the island. Continued attacks by a smaller force against a larger defending force rarely bear any fruit. With supply to the island already tenuous and not a lot of materiel to go around regardless, a battle of attrition was precisely the situation the Japanese needed to avoid.