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SCR-270 Early Warning Radar at Pearl Harbor


Radar Operators at Pearl Harbor on December 7, 1941

Photo of private George Elliot and Joe Lockard

Left to right: Lt. Kermit Tyler, Pvt. George Elliot & Pvt. Joe Lockard. Photos on display at the National Electronics Museum.

Private George Elliot and Private Joe Lockard were the radar operators at the Opana Station on that day and at 7:00 A.M. were preparing to shut down the SCR-270 radar system. The truck had not arrived to return them to base so they kept the radar operating for additional training.

The radio operators detected a large echo on the SCR 270 radar oscilloscope at 7:02 A.M. on December 7, 1941, which later proved to be the Japanese attack force heading for Pearl Harbor.

Early Radar Warning Ignored

Museum display of SCR-279 radar inside trailer.

Model of a portable SCR-270 unit. U.S. Army photo

The blip was so large that Lockard thought the radar was malfunctioning, however, Elliot insisted on contacting the Aircraft Warning Information Center. The Center was virtually empty due to early morning training and monitoring exercies. The officer on duty, Lt. Kermit Tyler1 had been at the center for only two days, and had no training in radar.

He did know that a flight of US B-17 Flying Fortresses were expected that day and believed this is what the operators had detected. He relayed back to the radar operators, Don't worry about it. Lockard and Elliot continued tracking the aircraft until they were about 22 miles from Oahu, when they planes disappeared behind the distortions caused by surrounding mountains. The two radio operators then returned to base.

At little after 8:00 A.M. Lockard and Elliott learned Japanese aircraft were attacking the base at Pearl Harbor and realized that what they had previously tracked with the radar, was the Japanese attack force.

General Short's Views on Radar Prior to the Japanese Attack

* Radar Detection of Japanese Aircraft

7:00 am
Radar operators at Opana Station prepare to shut down.
7:02 am Large echo detected on the SCR-270 radar.
  Aircraft Warning Information Center contacted.

Return message was,
"Don't worry about it."
Shortly after 8:00 am Japanese planes attack Pearl Harbor. Radio operators Elliot and Lockard realize attack force detected by radar

First use of radar by U.S. forces in warfare.
* Table based on information from signs at the National Electronics Museum.

General Short, who was in overall command of the U.S. Army units on Oahu at the time of the Japanese attack on Pearl Harbor, firmly believed in the value of the infantry – so much so that he required air force personnel to participate in six weeks of infantry training. And reflecting this thinking, he didn't place much importance on the radar units, restricting training and operation times. Radar units were to be operated only between 4 a.m. and 7 a.m. in the morning, so they would not interfere with normal army operations during the day.

This was not true when specific war exercises were conducted. So on November 12, 1941, during a major war game, (less than a month before the attack), the radar units were operated full time. One of the American carrier groups simulated an attack on Pearl Harbor and the radar units identified the incoming planes. The radar worked the way it was meant to work.

But when the war game was over, radar units went back to the curtailed schedule, being only used for training small numbers of soldiers in the early hours of the day and shut down during normal working hours. This schedule was designed to get all the important work done between 8:00 am and 5:00 pm, Monday through Friday, and allow the soldiers to have the weekends off. This whole system was really predicated on the United States being at peace and not at war. The overall defense plan for Hawaii reflected this as well.

Military Value of Radar Proved at Pearl Harbor


The detection of the incoming Japanese fighters, dive-bombers, and torpedo planes on December 7, 1941, was the first time radar had been used in warfare by U.S. forces.

At the time of the Pearl Harbor attack, there were five operational radar stations on Oahu, with a sixth additional station authorized, but not yet installed. Three fixed radar sites which would use the SCR-271 radar were planned, but not yet built.2 It was the mobile station located at Opana Point, on the northern tip of Oahu, that detected the the incoming Japanese aircraft. Although the early warning was ignored this time, the successful detection of the planes proved the military value of radar.


1Because of the circumstances, Lt. Kermit Tyler was not disciplined for neglecting to report the radar detection to his superiors.
2LTC Jeffrey J. Gudmens. Staff Ride Handbook for the Attack on Pearl Harbor, 7 December 1941:A Study of Defending America. Fort Leavenworth: Combat Studies Institute Press. p.91.

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