The History of the Opana Radar Site

May 12, 2018

Nearly an hour before the attack on Pearl Harbor unfolded, there was activity brewing at a small radar site located on the North Shore of Oahu. The Opana Radar Site plays a role in the story of the attack, even though it didn’t quite get to operate as it was intended to. It’s one of many historic sites on Oahu that tell a part of the Pearl Harbor story, adding another piece to the puzzle of the morning of December 7 leading up to the final approach of Japan’s aerial fleet.

Opening the Opana Radar Site

Almost exactly two years before the Japanese bombs and torpedoes caused havoc at the US Navy base, the United States military began implementing a new system in order to defend American territory from incoming attack. The Aircraft Warning Service utilized the SCR-270 radar, the first long-range radar developed by the United States.

Opana Radar Site, North Shore Oahu

Opana Radar Site, North Shore Oahu

The warning system was designed at the Signal Corps laboratories at Fort Monmouth, NJ in 1937. The radar could operate at up to 150 miles and so was the perfect tool for protecting the Hawaiian Islands as it would provide enough of a warning of any aircraft coming in range.

When the SCR-270 was ready for operation, Col. Wilfred H. Tetley ordered the Aircraft Warning Service to create six mobile radar sites on Oahu. The sites were to be built at Waianae, Ka’a’awa, Koko Head, Fort Shafter, Kawaiola, and Schofield Barracks. Five of the sites were activated as ordered, but on Thanksgiving, 1941, the Schofield Barracks radar was moved to a location 532’ above sea level. With its unobstructed view of the Pacific and higher elevation, this site would have a greater range than the others. This was the Opana Radar Site and required four trucks carrying a transmitter, water cooler, receiver, antenna, oscilloscope, operator, modulator, and generator. It wasn’t intended to be a permanent structure and was designed to be removable when the time arose. Unfortunately, despite its higher vantage point, the site’s usefulness was hindered by human error on the part of those in command.

A Missed Warning

In the early hours of December 7, 1941, the Opana Radar Site was operating as expected with Privates Joseph Lockard and George Elliot overseeing the new SCR-270. Training on the new device hadn’t been as thorough as it should have been, leaving both Lockard and Elliot to operate it to the best of their abilities. At 7:02 am, despite the unfamiliar equipment and the fact that the site’s operating day had technically ended, Elliot detected what looked like a large number of approaching aircraft. He may have been still practicing with the equipment, but he was sure of what he was seeing.

They called Fort Shafter with this information, especially worrisome as they weren’t aware of any scheduled arrivals. Unfortunately, the information passed on by Lockard and Elliot from the Opana Radar Site was dismissed.

Elliot’s message was passed along to Lt. Kermit Tyler, who dismissed it as nothing with the words, "Don't worry about it."  Tyler suggested that, if anything, it was a fleet of B-17 Flying Fortresses expected in from San Diego.

Opana Today

Opana Radar Site historical marker

Opana Radar Site historical marker

The Opana Radar Site was removed long ago, eventually being replaced by a new telecommunications station of the Department of State’s Diplomatic Telecommunications Service.

The SCR-270 mobile unit was removed, but the site where it once stood was registered as a National Historic Landmark and an Institute of Electrical and Electronics Engineers Milestone. A commemorative plaque was installed at the foot of Opana Hill on the grounds of the Turtle Bay Resort on Oahu’s North Shore.

Travelers can visit the plaque, which provides details on the history of the site and its use during World War II.

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