In the age we live in today, with miniaturization of electronic devices commonplace, the packaging difficulties of fitting a working radar transceiver into a 5-inch shell weighing 55 pounds may seem unremarkable. Vacuum tube technology of the time, however, meant that they were regularly replaced, and when used under wartime conditions in radios and other devices, veryregularly replaced. Developing a single tube that could withstand the shock of gunfire was achievement enough. What the APL team achieved was a complete transceiver unit itself smaller than most vacuum tubes of the era.
The USS Helena (CL 50) at a South Pacific base, between battles, circa 1943. This image has been retouched to remove radar antennas from the gun directors and masts. The USS Helena was among the first ships to test the “funny fuze.” U.S. Naval History and Heritage Command photo
After making the “impossible” a reality and going through development of test and prototype fuzes, Section T/APL helped set up series production, maintained quality control through troubleshooting and plant inspections (shutting several down when the components were not of suitable quality) and traveled to the various fronts during the war to train personnel in the use of the new weapon.
The U.S. Navy had assigned the highest priority to developing the weapon, which was often called the Variable Time (VT) fuze, the Radio Proximity Fuze, or Proximity Fuze, but was more popularly referred to, at least by sailors throughout the Navy, as the “funny fuze.” By spring 1941, it was also decided that the Navy had the greatest need for the completed proximity-fuzed anti-aircraft shells, with the Royal Navy next in line, followed by the U.S. Army and British Army. One reason for the order of priority was that naval forces firing the proximity fuzed projectiles at sea stood a very low risk of the fuzes falling into enemy hands, as duds would fall into the ocean depths.
The Combined Chiefs of Staff decided that the first use of the fuze would be in the South Pacific, where Japanese aircraft were causing heavy losses in ships and personnel and the need was greatest. As production ramped up, the first 5,000 proximity fuzed shells were shepherded by then-Cmdr. W.S. Parsons, who later fuzed the first atomic bomb aboard Enola Gay, during their shipment to New Caledonia, where Parsons reported to Adm. William F. Halsey. The shells were divided among the carriers USS Enterprise and USS Saratoga and the cruiser USS Helena, all of the Third Fleet. Personnel aboard all three ships were trained and indoctrinated in the potential of the new weapon. The first combat test of the proximity fuze proved that the efforts of Section T/APL were worth the time and expense that had gone into the project.
“On 5 January 1943,” wrote Parsons, “four dive bombers attacked the task force (then near Guadalcanal). One streaked by the cruiser USS Helena. Two rounds were fired and the first victim of the Proximity Fuze burst into flames and crashed into the sea.”
As James F. Dunnigan and Albert I. Nofi wrote in Victory at Sea: World War II in the Pacific:
A Japanese torpedo bomber is destroyed by a 5-inch shell from USS Yorktown (CV 10) off Kwajalein atoll. By 1943, although only a quarter of antiaircraft ammunition used proximity fuzes that quarter accounted for 50 percent of Japanese aircraft shot down by AA fire. National Archives photo
“By 1943, although only about 25 percent of AA ammo issued to the fleet had proximity fuzes, these accounted for about 50 percent of Japanese aircraft shot down, making them about 300 percent more effective than the old timed or impact fuzes. By 1945 this had risen to nearly 600 percent, and this despite the fact that perhaps 30 percent of proximity fuzed rounds were duds!
“With the rapid development by the U.S. Navy of Combat Information Centers aboard ship to direct fighters toward incoming raids and radar-controlled gun directors laying down large-caliber anti-aircraft fire, with up to 50 percent of the shells proximity-fuzed, even mass saturation attacks by enemy aircraft could be broken up, driven off, or annihilated.”
“The general impression was that the horizon from the east to the northwest was full of burning planes,” read one combat report from a destroyer in the Pacific. “There were too many to count.”
As the Pacific War continued, defeat loomed for Japan. Losses of experienced pilots had become so high that the percentages of bomb and torpedo hits were down near the single digits. Tactics became more desperate. The success of the proximity fuze, central fighter direction, and radar eventually made normal attacks on U.S. task forces impossible, and in some ways brought about the most terrible tactic yet developed by the Japanese in the Pacific War: the Kamikaze.
A Kamikaze attack seen from the deck of the USS Kitkun Bay, June, 1944. The success of the “funny fuze” may have contributed to the Japanese decision to resort to the Kamikaze attack. National Archives photo
Attacks were now pressed home until impact, and small caliber anti-aircraft fire alone, even putting up a “wall of lead,” was often not enough to destroy a plane or knock it off its ballistic trajectory. Though the loss rates of Japanese pilots were staggering, the numbers of U.S. ships sunk and personnel killed were equally grievous. The Navy suffered thousands of casualties from the Kamikaze attacks, and at Okinawa alone, lost 21 ships sunk and 66 damaged, two-thirds of them still being repaired when the war ended. The carnage that would have taken place if the home islands were invaded would have been incalculable for both sides. The invasion of Japan, of course, never took place. An even more destructive weapon had brought about surrender, but the proximity fuze had contributed mightily to the rapid march across the Pacific.
As Secretary of the Navy James V. Forrestal put it: “Without the protection this ingenious device has given the surface ships of the Fleet, our Westward push could not have been so swift, and the cost in men and ships would have been immeasurably greater.”