At first, Army Pvt. Joseph Lockard thought something was wrong with his equipment. Never in the six months he had been operating the Signal Corps Radio-270 Radio Detection and Ranging (read: radar) system in Hawaii had he seen such a large indication on the screen.
"But I made some checks and everything was working," Mr. Lockard recalled last week. "Then I saw [the line] moving and I knew something was there."
The time was shortly after 7 a.m. on Dec. 7, 1941. What was there turned out to be a wave of Japanese bombers, heading for the U.S. naval station at Pearl Harbor.
Private Lockard and his partner George Elliott -- who could not tell from the primitive instruments if what the screen showed was friend or foe -- notified one of their superiors. Thinking the radar device had picked up a squadron of B-17 bombers due to arrive from the U.S. mainland, he told them not to worry.
The rest is part of electronic -- as well as world -- history. While the attack marked the entrance of the U.S. into World War II, it also proved that the new radar system, manufactured by Westinghouse Electric here, would work under real combat conditions.
Today at 11 a.m., the Historical Electronics Museum on Elkridge Landing Road near BWI airport will unveil at a special ceremony its latest artifact: one of the series of the same kind of radar that picked up the Japanese planes heading for Pearl Harbor 50 years ago. The ceremony is by invitation only but the museum is holding a special open house Saturday from 9 a.m. to 3 p.m.
The ceremony will include the presentation of plaques by the Institute of Electronic and Electrical Engineers to Mr. Lockard, who is 69 and lives in Harrisburg, Pa., on behalf of the Signal Corps Aircraft Warning Hawaii; to Westinghouse, for manufacturing the radar system; and to John J. Slattery, a civilian engineer with the Army Signal Corps, which developed it.
Harold M. Watson of Catonsville, a Westinghouse retiree and volunteer at the museum, spent about three years searching for one of the SCR-270 series devices, of which he says about 800 were built. He first found one in China, which received three of them after the war, made 150 copies and used them for years as its first-line radar defense on the Russian border. But then came the chilling of relations between China and the United States following the bloody putdown of the 1989 Tiananmen Square protests, and he worried it might be years before the museum could get it out of the country.
After several more phone calls, he finally located one at the University of Saskatchewan, which agreed to give it to the museum. The 60-foot-high device, which resembles an oil rig, had been used at the university as scaffolding to support astronomical equipment.
Before the attack on Pearl Harbor, Mr. Watson said, there was a good deal of scepticism that the device would work. "One of the books we have in our library is called 'Radar: The Reluctant Miracle.' It took Pearl Harbor to say, 'Here's a device that will actually give warning,' " he said.
But Mr. Slattery, 82, one of a small group of engineers who had worked on sound-ranging detection systems at Fort Monmouth,
N.J., since the early 1930s, says his team did not know for several days thatthe radar had worked. They thought the success of the Japanese mission was the result of the system's inability to detect the incoming bombers.
"We just assumed the equipment had failed," recalled Mr. Slattery, now retired and living in Arizona. "We ran around in absolute gloom. We naturally felt guilty."
Once the word got out, he said, demand for the device "rose precipitously." He praises the work of Westinghouse engineers in their production. "What the industrial people did was turn it from a lab product to a product that could be copied," he said.
He also notes its lack of sophistication compared to current radar systems. "Our stuff was like the club of a savage compared to a ground-to-air missle," he said.
Where: Historical Electronic Museum, 920 Elkridge Landing Road, Linthicum.
Hours: Mondays to Fridays, 9 a.m. to 3 p.m.; 10 a.m. to 2 p.m. the first Saturday of each month. A special open house will be held this Saturday from 9 a.m. to 3 p.m.
Call: (410) 765-2345.