Battle of Edson’s “Bloody” Ridge

Unit Force

• 1^st raider Battalion
• U.S. Marine 1^st Parachute Battalion

Opposing Forces

• 35^th Infantry Brigade

Operation

During August 1942, the Japanese Forces move reinforcements to Guadalcanal in nightly runs by destroyers and barges, a process soon dubbed the “Tokyo Express.” On August 21^st, 1942, the Marines repulse the first enemy attack at the Tenaru River. However, Major General Alexander A. Vandegrift, commander of the 1^st Marine Division on Guadacanal realises he needs all the strength he can muster to defend the extended perimeter surrounding the airfield.

The Japanese force is led by Major General Kiyotaki Kawaguchi, commanding the 35^th Infantry Brigade with 6,200 soldiers. Confident in his ability to capture Henderson Field with his five infantry battalions, he turns down an additional battalion offered by the 17^th Army. The Japanese believe there are only 2,000 Marines defending Henderson Field, rather than the actual 10,000.

Kawaguchi plans a three-pronged attack: one battalion is to attack Henderson Field from the southwest, the main body under his command is to attack from the south, and the final battalion is to attack from the southeast.

At the end of the month, Major General Alexander A. Vandegrift brings the 1^st raider Battalion and U.S. Marine 1^st Parachute Battalion across the island and places them in reserve near Lunga Point. The 1^st parachute battalion has suffered heavily in its assault on Gavutu-Tanambogo, including the loss of its commander. As a result, Vandegrift attaches the 1^st Parachute Battalion to Colonel “Red Mike’s” Edson’s force for reinforcement.

Colonel Edson, commander of the 1^st Raider Battalion, quickly establishes a rapport with Lieutenant Colonel Thomas, the division operations officer, and convinces him to use the raiders offensively. The first product of this effort is a two-company patrol on September 4^th, 1942, to Savo Island, where intelligence believes the enemy has an observation post. While Griffith commands that operation, Colonel Edson plans a reconnaissance-in-force against Cape Esperance for the next day.

When the Savo patrol returns in the late afternoon aboard the Fast Amphibious Transports, the U.S.S. Little (APD 4) and U.S.S. Gregory (APD 3), the men begin debarking before receiving the order to remain on board for the next mission. Once aware of the mix-up, Edson allows the offload process to proceed to completion. That night, Japanese destroyers of the Tokyo Express sink the two Transport Destoyers (APD’s), marking the raiders’ second close escape. During their shift to Guadalcanal, enemy planes had sunk the U.S.S. Colhoun (APD 2) just after it had unloaded a company.

September 7th, 1942

Native scouts inform Major General Vandegrift that the Japanese have occupied the village of Tasimboko with 200-300 soldiers. In response, he swiftly deploys a composite battalion from the 1^st Raider Battalion and the U.S. Marine 1^st Parachute Battalion, totaling 849 men, aboard the destroyers U.S.S. McKean, U.S.S. Manley, and two YP boats. Their mission is to land at Taivu Point, Guadacanal, and engage the Japanese forces.

September 8th, 1942

Before the landing, intelligence updates the estimated Japanese strength to 2,000-3,000 soldiers.

The combined raider force under Colonel Edson makes initial contact with a 300-man Japanese security element in what becomes known as the Tasimboko Raid. Assessing the situation, Edson requests air support, which arrives in the form of Bell P-39 Airacobra’s and Douglas SBD Dauntless’s. Despite requesting reinforcements, his appeal for a second battalion is denied. Undeterred, Colonel Edson orchestrates a three-pronged assault on Tasimboko: one company advances along the coast from the east, another moves slightly inland from the southeast, and the final company attacks from the south.

Upon entering the village, it becomes clear that the Japanese have retreated in haste. Edson’s forces seize the opportunity to destroy significant enemy resources, including two weeks’ worth of supplies intended for 6,000 soldiers, 16 pieces of artillery, and a radio station. After the successful raid, they return to their base and fortify positions along Henderson Field’s southern perimeter.

The raid results in the death of at least 27 Japanese soldiers, at the cost of two Marines killed and six wounded. More crucially, the operation disrupts Kawaguchi’s main force and provides vital intelligence on the strength and composition of the Japanese troops advancing towards Henderson Field. This information proves invaluable for the impending battles.

The arrival of the parachute battalion results, in a coordinated attack with the raider battailon. The combined force overruns the Japanese positions. The enemy forces, estimated at 4,000, choose to break contact, allowing the destruction of their abandoned encampment. These forces are part of the Kawaguchi Force, which is preparing a strong counterattack on the airfield, to be blocked by Edson’s raiders in the Battle of Bloody Ridge four days later. The combined raider-parachutist force withdraws and is placed in the division’s reserve.

September 9th, 1942 – September 11th, 1942

General Vandegrift orders the combined force into a 3.7-kilometre defence line maintained by the 1^st Marines Division east of the Lunga River. Colonel Edson deploys his 830 men south of Henderson Field in a series of mutually supporting strongholds. The Lunga River flanks them to the west, but there is a gap in the lines to the east. Meanwhile, Marine patrols continue to disrupt Kawaguchi’s march towards the airfield. Meanwhile, the Japanese continue aerial bombardments of Henderson Field.

September 12th, 1942

During the night, sporadic contact occurs along the ridgeline assigned to the raiders and parachutists. Throughout the daylight hours, the unit is under periodic sniper fire, the combined force digs in for another night.

A pre-assault strike by 40 Japanese aircraft inflicts significant damage on the airfield. By sundown, Kawaguchi has only three of his five battalions (2,506 men) in position for the attack, staged in front of Edson’s combined Parachute/Raider Battalion. At 20:45, Colonel Edson receives reports of Japanese movement to his front and calls for artillery fire. The 5^th Battalion, 11^th Marines Regiment responds with a barrage. The Japanese attack begins in earnest at 21:30 when aircraft drop flares, and a cruiser and three destroyers shell the perimeter. Kawaguchi launches his first attack against the centre and right of the line. By 22:00 hours, it is estimated that two understrength U.S. Marine parachute companies, plus Company B (minus one platoon) of the 1^st Raider Battailon, face at least two enemy battalions.

The Japanese achieve limited success due to the terrain, darkness, and confusion.

September 13th, 1942

Through the night, the Japanese Forces initiates at least a dozen assaults to break the combined Force on Bloody Ridge. They fail to do so and the Japanese break halt the attack and retreat to reorganise. During the morning, a Japanese reconnaissance flight is followed by a Japanese bombing raid with 26 bombers and 12 fighter escorts. Uncertain of the airfield’s ownership, they mistakenly bomb and strafe Taivu Point, attacking their own forces. The Cactus Air Force (Nickname for the ensemble of Allied air power assigned to the island of Guadalcanal) shoots down several aircraft and straves the retreating Japanese Forces. In the event, the Allied aircraft suffer several losses.

Throughout the day, as Major General Kiyotaki Kawaguchi prepares to attack, Colonel Edson strengthens his defences. Edson shortens the defence line by nearly 100 metres to force the Japanese to cross open ground under automatic-weapons fire. He improves the fields of fire, lays wire, and digs deeper fighting holes. The 1^st Marine Division places its reserve, the 2^nd Battalion, 5^th Marines Regiment, behind Edson’s position.

The Japanese ground assault begins shortly after dark at 18:30. All three of Major General Kiyotaki Kawaguchi’s battalions attack, trying to exploit gaps in the American lines. The Marines fight hard and use artillery danger close to their positions to repel the assaults. Despite their efforts, they are forced to fall back up the ridge, getting closer to the airfield. Once the withdrawal is complete, 300 Marines set up a tight perimeter around the knoll, later known as Edson’s “Bloody Ridge.” Colonel Edson walks artillery fire up the hill until it is danger-close again. The steep terrain makes grenade use easy and effective. The Japanese initiate each attack with a flare.

Around 22:00, Kawaguchi’s right wing finally enters the fight, engaging the 3^rd Battalion, 1^st Marine Regiment. Their assault is disorganised, and they become entangled in barbed wire before withdrawing, losing 27 men, including the battalion commander. The Marines suffer four killed and three wounded.

September 14th, 1942

That night U.S. Artillery plays a critical role in the battle. The 5^th Battalion, 11^th Marine Regiment fires 1,992 105-mm howitzer rounds on the Japanese attackers, inflicting the majority of Kawaguchi’s casualties.

At 04:00, after nearly 10 hours of defence, the 1^st Marine Division reinforces Colonel Edson’s lines with their reserve. Two more Japanese assaults occur, and in the last at 05:30, about 60 Japanese soldiers break through the lines. However, they are quickly overrun by two companies from the U.S. Marine 1^st Engineer Battalion.

As the sun rises, the Cactus Air Force launches three P-39s from the 67th Fighter Squadron to engage Japanese targets on the ground. Two aircraft are hit by ground fire and forced to return to Henderson Field. The air battle culminates that evening with a Japanese attack by 19 aircraft from the light carrier Chitose. The U.S. shoots down 10 of the 19 aircraft with no losses.

September 15th, 1942

The Japanese ground forces attack again during the night with minimal effect. After these actions the unity of the Japanese Forces is destroyed. The remnants withdraw around Mount Austen towards Kokumbona and never again pose a viable threat.

Aftermath

The battle results in 111 Marines killed and 283 wounded. The Japanese suffer approximately 700-800 killed or missing and 500 wounded. The U.S. Forces continue to strengthen their defence and prepare for future offensive actions. The scene of the battle becomes known as “Edson’s Ridge” or “Bloody Ridge” due to the carnage and the leadership of Colonel Edson. Despite the failure of outer defensive rings to prevent Japanese reinforcements, aggressive patrolling and tenacious close-in defence effectively counter the enemy.

Colonel Edson, commanding the joint raider-parachutist force, is awarded the Medal of Honor for the Bloody Ridge action. Major Kenneth D. Bailey, killed in a later engagement on Guadalcanal, is posthumously awarded the Medal of Honor for leading his troops in hand-to-hand combat for over ten hours on the Ridge.

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