Opana Mobile Radar Site

A historic photo of a young man, George Elliott, in a military uniform.
Private George Elliott

Radar Operations on O‘ahu

On the morning of December 7, 1941, five mobile radar stations were active on O‘ahu, while a sixth, at Fort Shafter, had yet to begin operations. At 7:00 AM, all but the Opana site were shut down, though they would later be reactivated.

Tracking the Japanese Planes

At the Opana station, Privates Joseph Lockard and George Elliott detected incoming Japanese planes at 7:02 AM. They continued tracking them until around 7:40 AM, when the signal was lost due to background interference.

 
Pvt. Joseph Lockard, a young man leaning over a table that has electronic equipment.
Pvt. Joseph Lockard

The Missed Warning at Opana Radar Site

Army Private Joseph Lockard, along with Private George Elliott, was on duty at the Opana Radar Site on the morning of December 7, 1941. After detecting a large flight of planes heading toward O‘ahu, they quickly reported their findings to the information center at Fort Shafter. At the time, Private Joseph McDonald and newly assigned Air Corps Lieutenant Kermit Tyler were on duty, as the plotters had left just a few minutes earlier.

When Lockard informed Tyler of the radar detection, Tyler, still in his second day of training as an observer, reassured the radar operators not to worry. He believed the radar contact was a scheduled flight of B-17s arriving from the West Coast and did not recognize the approaching threat. This misjudgment allowed the attack force to proceed unnoticed until it was too late.

 
Opana Radar Plot
Opana Radar Plot.

The Opana Radar Plot: Detecting the Incoming Threat

The radar operators at the Opana site created a plot on the morning of December 7, 1941, tracking the incoming Japanese planes as they approached the North Shore of O‘ahu. The five mobile radar units positioned around the island were intended to compensate for the lack of patrol plane coverage, but despite detecting the approaching aircraft, the operators were unable to recognize the impending attack.

Lieutenant Kermit A. Tyler later explained, “A few plots showed up [on radar] starting around 6:15 AM, which could have been Japanese scout planes, but there was no way of telling what they were. The problem was, we had no identification people on staff yet.”

  • 7:02 AM: The first wave of Japanese aircraft appeared on radar, 137 miles north of O‘ahu.
  • 7:06 AM: Private George Elliott contacted the Information Center at Fort Shafter to report a large target 113 miles out.
  • 7:15 AM: The planes were now 92 miles away, traveling at an airspeed of 180 mph.
  • 7:23 AM: Although the planes were headed straight for O‘ahu, the radar showed a zigzag pattern, adding to the difficulty of interpreting the data.
  • 7:45 AM: Radar contact was lost as the aircraft flew closer to the radar station.
  • 7:50 AM: The Japanese air attack on O‘ahu began at Wheeler Army Airfield.

This sequence of events reveals the challenges faced by the radar operators, who detected the incoming threat but were unable to identify its true nature in time.

 
Opana Radar Station
Opana Radar Station.

Opana Radar Site: The Moments Before the Attack

The Opana Radar Site, located just inland from the north shore of O‘ahu, played a key role in detecting the approaching Japanese planes on December 7, 1941. Privates George Elliott and Joseph Lockard tracked the radar signal until 7:39 AM, when the echo was lost due to interference caused by the surrounding mountains.

Shortly afterward, a truck arrived to take them to breakfast. As they returned to camp, they noticed black, oily smoke rising from the direction of Pearl Harbor. It was then that Lockard and Elliott realized the significance of what they had seen on radar—the opening moments of the attack on Pearl Harbor.

Last updated: September 25, 2024

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