Marines reinforced on Guadalcanal

26th September 1942: Perimeter defences are strengthened while air battles over the island lead to the award of the Medal of Honor to two Marine aviators

Marine gun emplacement on Guadalcanal

The 1st Marine Regiment of the First Marine Division had arrived on Guadalcanal in the Solomon Islands at the beginning of August. They had successfully secured the Japanese built airfield, now known as Henderson Field and had fought some intense engagements as the Japanese sought to retake it.

But with the seas around the Solomons still contested it had been difficult to keep them resupplied. Things began to change on the 18th September with the arrival of the 7th Marine Regiment.

Drying machine gun belts on Guadalcanal.

The first priority was to strengthen their perimeter defences. Merril B. Twining¹ describes the importance of machine guns in bolstering this thin line:

Turning to Edson, Vandegrift asked, “How great a distance do you believe we could leave between separate combat groups and still prevent infiltration at night?” “Fifteen yards!” Edson replied instantly.

I was instructed to draft the order on the basis of a cordon defense. This order continued in effect during the remainder of our presence on the island without material change. It also contained another statement: The de­fense of Guadalcanal will be primarily by air. Our tacit tribute to the role of Henderson Field, General Geiger, and the Cactus Air Force, it may well have been a first in the history of the U.S. armed forces.

Our positions were now well dug in, with standing foxholes for the crews of heavy weapons. For the first time, men and weapons were well protected with bands of barbed wire that had come in with the 7th Marines. No longer would we be dependent on a single strand of trip wire salvaged from coconut plantation fences.

“Their position is like the hard shell of a giant tortoise, which emits fire and flame wherever it is touched.”

But best of all was a massive increase in firepower brought about by the cumulative effect of a fortuitous error in judgment made by some zombie back in Headquarters Marine Corps.

Our amphibian tractors (LVTs), at that time not even accorded a combat capability, had each been given an armament of five machine guns: one .50 caliber and four .30 caliber. There were 100 LVTs in the battalion. These 500 machine guns exceeded by many times the division’s entire normal allotment. Manna from heaven! These guns were distributed along the front and placed in the hands of gunners extemporized on the spot and taught the rudiments if not the refinements of their new trade.

U.S. Marine Corps LVT(1) amphibian tractors move toward the beach on Guadalcanal Island. This view was probably taken during the 7-9 August 1942 initial landings on Guadalcanal. The troopship USS President Hayes (AP-39) is in the background.

This single increment, I believe, was the decisive element in the unbroken success of our defense, even though we were invariably greatly outnumbered by the Japanese at the point of contact, which was a point they had the option of selecting and attacking in overwhelming initial force.

One Japanese officer who had apparently been around the track a few times left us a note in his diary: “Their position is like the hard shell of a giant tortoise, which emits fire and flame wherever it is touched.”

A U.S. Navy Grumman F4F-3 in non-specular blue-grey over light-grey scheme in early 1942.

Their positions did not allow for the defence in depth, as the airfield was immediately behind them, leading to the dictum: ‘The de­fense of Guadalcanal will be primarily by air.’