On 5 January 1943, Task Group 67.2, commanded by Rear Admiral Mahlon S. Tisdale, carried out a bombardment against airfields and military installations at Munda, on the Japanese-occupied island of New Georgia in the Solomons. Shortly after the remainder of Task Force 67 joined up with Tisdale’s warships, Japanese aircraft launched attacks on the force—air strikes that resulted in the near miss of the light cruiser USS Honolulu (CL 48) and the damaging of the New Zealand light cruiser HMNZS Achilles. During this action the light cruiser USS Helena (CL 50) became the first U.S. Navy warship to employ the new Variable Time (VT) or proximity-fused antiaircraft shells to defend the ship against the attacking planes. Her VT-armed 5-inch/38 guns succeeded in downing a Japanese Aichi Type 99 VAL carrier bomber in the fight.
The then highly secret VT shell relied on a radar fuse located in its nose to give off radio waves that bounced off the incoming plane, and when the shell came within a lethal distance of the aircraft it automatically exploded—knocking its target out of the sky. Although it was used by U.S. Navy combatants in the Pacific in the months that followed, this wonder weapon achieved its greatest role some two and half years later, in the waters off Okinawa, Japan. There, during the lengthy fighting to seize that pivotal island, proximity-fused antiaircraft shells from the quad 40mm and 5-inch/38 guns of destroyer escorts, destroyers, cruisers, and battleships in the Fleet shot down hundreds of Japanese Kamikaze aircraft whose pilots were bent on hitting the American ships offshore by crashing into them. By downing these suicide planes before they could hit their targets, the VT-fused shells saved the lives of thousands of Allied sailors who otherwise would have been killed.