Thursday, June 1, 1972
'Smart Bombs' Wrecking Red Supply Routes
SAIGON (AP) --One of the most dramatic changes in the resumption of full-scale bombing of North Vietnam has been the wide use of electronic "smart" bombs by U.S. Air Force fighter-bombers.Guided by laser beams and television cameras to their targets, the bombs' almost pinpoint accuracy has accomplished more in two months against certain type targets than the entire 1965-68 bombing campaign, American officials say."We've been able to cut most major bridges and roads from the defense lines north of Hue up to the Chinese border," says one official. "Both the northeast and northwest rail lines linking Hanoi with China have been cut."Officials report there have been no signs of major movement of war materials from China southward either by rail or truck. It had been anticipated that with the blockade by mines of Haiphong harbor, the North Vietnamese may rely on shipments of war materials overland from China.Even with the rail lines cut they could truck the supplies down over hundreds of secondary roads, officials say."But they have not begun to adjust yet to using trucks from the Chinese border," reports one source. "They may not have enough trucks. It would take up to 1,000 trucks to offload a 100-car freight train with the rail lines cut."The smart bombs had been in the development stage for two years and were used only on a limited basis in Indochina until the United States resumed the bombing of North Vietnam April 6 in retaliation for the Communist offensive across the Demilitarized Zone."The tactics of how to use the smart bombs under hostile conditions had not been really developed," says a source. But that was all changed by the North Vietnamese offensive and the tactics of successfully employing the electronic bombs began to bear fruit in April, the source adds.Generally, a flight of two jets operate together in using the laser bombs. One is armed with a laser gun that throws a light ray, much like that of a flashlight, on the target. But the ray is narrow, like a rope, and does not expand as would a flashlight fixed to the side of a barn.The second jet drops the bomb, fitted with a mechanism in its nose that homes in on the light ray. U.S. officials say the margin of error for a laser bomb if five feet or less.A "dumb" iron bomb dropped with normal trajectory has a margin of error of 150 feet taking into consideration the plane's air speed and altitude and the wind conditions. All detract from the accuracy of a nonelectronic bomb.The laser-guided bombs are generally 2,000 and 3,000 pound blockbusters used on bridges ranging anywhere from seven feet wide to more than 50 feet wide.Officials point out that if would be most difficult to knock out a seven-foot wide bridge using a dumb bomb that has a margin of error of 150 feet.Among the major targets reported destroyed by 2,000 and 3,000 pound laser guided bombs was the Thanh Hoa "Dragon's Jaw" bridge, 80 miles south of Hanoi. It was knocked out May 12 by 16 Air Force F4 Phantom fighter-bombers using laser bombs.The bridge had stood for seven years despite repeated earlier attacks with dumb bombs. Prior to its destruction with the laser bombs, more than 1,000 U.S. fighter-bombers had attacked the bridge since 1965 with no success.Thirty U.S. planes were lost in 1965-68 raids on the bridge. None was lost in the May 12 attack."Smart Bombs Wrecking Red Supply Routes", by (AP) published in the Pacific Stars and Stripes Thursday, June 1, 1972 and reprinted from European and Pacific Stars and Stripes, a Department of Defense publication copyright, 2002 European and Pacific Stars and Stripes.