Almost everyone raised in America knows the story of Pearl Harbor. On the morning of December 7, 1941—71 years ago today—the Japanese Imperial Navy launched a surprise attack on the U.S. naval base at Pearl Harbor in Hawaii, claiming eight battleships and other vessels, and 2,403 military and civilian lives, nearly as many as on 9/11. The next day, President Franklin D. Roosevelt delivered a speech to Congress in which he declared December 7, “a date which will live in infamy.” Almost immediately after his speech, the United States declared war on Japan.
December 7 is also a date that should live in the annals of technological innovation. What’s not as well known is that a new technology—called radar—had already been deployed in Hawaii. It provided the capability of seeing enemy planes far enough out to scramble at least some fighters to intercept, for gun crews to be ready, and for other military personnel and civilians to seek safety. The initial, 183-plane Japanese strike force took off shortly after 6 am from aircraft carriers located about 220 miles north of Oahu. Radar should have seen the Japanese coming, and that’s exactly what it did.
What follows is a short account of the Pearl Harbor attack from a technological point of view. (The account is drawn from The Invention That Changed the World, a book I wrote about radar for the Alfred P. Sloan Foundation’s Technology Series.) It’s a reminder that adopting great technology by itself is not enough. I’m not talking just about training those who use it, but about “functional integration,” which is much harder to accomplish. This is the idea that the entire chain of command must understand the power of the technology, and trust what it is telling them. And there must be a system to then act on that information. That’s where radar lost its way at Pearl Harbor.
The attack had begun in the pre-dawn hours of December 7, late morning on the East Coast. Radar might have prevented much of the devastation. At that moment, as it soon became known, the island of Oahu, third most westerly in the Hawaiian chain and home to the United States Pacific Fleet, lay enveloped in a radar curtain. The five sets providing the coverage, all U.S. Army mobile SCR-270s delivered the previous August and positioned around the island, penetrated the Pacific mist and extended their radio eyes some 150 miles out to sea. The stations, on the air since four that morning, were due to stay on alert until seven…
As early as 6:45, three of the sets—at Opana on the northern tip of Oahu, Kawailoa further west, and Kaaawa in the east—detected the first faint glimmers of the invaders but no action was taken. Just before seven, with an alarm yet to be raised, the order to shut down for the morning came through from the Information Center at Fort Shafter, where reconnaissance reports were charted.
All five stations began to sign off. At Opana, though, an excellent radar observation point 230 feet above sea level, Private George E. Elliott asked the more experienced Private Joseph L. Lockard for additional instruction time. Suddenly, the cathode ray screen came alive with so much clutter Lockard thought it had gone haywire. After a system check indicated all was well, the enlisted man decided that just beyond 130 miles northeast of Opana lay the biggest aircraft formation he had ever seen on radar. At Elliott’s insistence, Lockard raised the Information Center’s switchboard operator, who passed them on to Lieutenant Kermit Tyler, the only other man still on duty. As Tyler listened to Lockard’s report, a bell went off in his head. The Army paid a local radio station to broadcast music throughout the night whenever aircraft were headed for the island base as a way of furnishing the planes with a friendly homing signal. The lieutenant remembered hearing the Hawaiian melodies while driving to work that morning and concluded a flight of bombers must be approaching. He told Lockard to forget the radar signal. As a consequence, the two Opana-based privates silently plotted the first attack in to about twenty miles, when it disappeared in clutter from hills behind the station.
Beyond the green-capped crests, roughly an hour after the first detection, all hell broke loose. At 7:49 a.m., Lieutenant Commander Mitsuo Fuchida, chills innervating his spine, gave the attack signal—“To, To, To,”—the first syllable of the word totsugekiseyo, or charge. Fuchida’s plane swung around Barbers Point on the island’s southwest rim: Pearl Harbor lay almost due east, with the sprawl of Honolulu and the rising peak of Diamond Head beyond. The initial bombs had already dropped four minutes later when Fuchida cried out the famous Tora! Tora! Tora!—“Tiger” three times—that told the Japanese Navy the U.S. Pacific Fleet had been caught unawares.
After the attack, the U.S. military reevaluated and increased the urgency of its radar adoption and integration plans. The imperative for functional integration is well-known, and it was not new then, either. Many organizations work hard to accomplish it, and it doesn’t happen overnight. So from that point of view, there is nothing new in this account. It’s just a different way of remembering Pearl Harbor, paying tribute to those who lost their lives, and to those who work to protect us, both as soldiers and sailors, and as innovators.
