On Friday, one of the two reflagged ships, the supertanker Bridgeton, was damaged by a mine while it was being escorted by U.S. warships.
The Bridgeton and the gas carrier Gas Prince were the first of 11 Kuwaiti vessels to be given U.S. Navy protection after they were re-registered as U.S. vessels under President Reagan's plan to keep the war-torn waterway open to shipping.
Much of the oil used by Europe and Japan is transported through the gulf.
Iran and Iraq have both been attacking gulf shipping as an outgrowth of their nearly seven-year-old war. Kuwaiti ships have been a particular target for the Iranians because Kuwait has given Iraq political and financial support.
Defense Secretary Caspar W. Weinberger ordered Air Force C-5 cargo planes to fly the mine-sweeping helicopters and the 200 people who make up their crews and support personnel from Norfolk, Va., to a U.S. base on the Indian Ocean island of Diego Garcia, a Navy official said, speaking on the condition that he not be named.
Meanwhile, the USS Guadalcanal, an assault ship, has been ordered to cut short a training exercise in the northern Arabian Sea and head south for Diego Garcia. There, it will unload a battalion landing team of 600 Marines, take the Sea Stallions aboard and sail back north to the Persian Gulf, about 2,400 miles away. It will take the Guadalcanal several days to make the trip from Diego Garcia.
For strategic reasons, Pentagon sources would not detail departure or arrival times for the mine-sweeping operation.
Navy underwater demolition specialists have combed the section of the Persian Gulf where the Bridgeton hit the mine on Friday. Navy officials believe Iran planted the device, which blew a hole in the port side of the Bridgeton and prompted the three smaller, more vulnerable Navy escort ships to sail behind the supertanker.
Weinberger's decision to send the Guadalcanal and the helicopter force to the gulf follows an order from Reagan on Tuesday for stepped-up protection, as well as sharp criticism from Congress about the lack of mine-sweeping forces in the gulf.
Despite early warnings that mines might pose a threat to the U.S. plan to escort reflagged Kuwaiti tankers, the Navy did not send any of its three mine sweepers or its mine-detecting helicopters to the area for the first escort operation last week.
"The issue is why didn't they do that before," said an aide to the House Armed Services Committee. "We raised the issue of mines with the Navy in May, and what we got was a general brush-off."
In Kuwait yesterday, 20-knot winds and nine-foot waves delayed the loading of crude oil onto the 401,000-ton Bridgeton. Cables holding the 1,200-foot- long ship broke in the high winds, and the Bridgeton dropped anchor to await calmer seas.
The U.S. Coast Guard said yesterday that it had given approval for the Bridgeton to take on a partial load of crude oil in Kuwait and sail out of the Persian Gulf, where it is to transfer its cargo to other tankers. It then is scheduled to sail for Dubai or Bahrain for repairs.
A Coast Guard spokesman, Warner Siems, told the Associated Press that the supertanker would be allowed to carry a maximum of 230,000 metric tons of crude oil. No oil can be carried in tanks adjacent to damaged areas.
Shipping officials said weather problems could delay the return trip through the gulf by the Bridgeton and the Gas Prince.
Although departure of the Sea Stallion helicopters from Norfolk was imminent, the actual U.S. mine-sweeping operations in the gulf may not get under way for at least a week, military experts said.
The Sea Stallions are single-rotor, twin-engine aircraft modified to tow different types of sonar and mine-sweeping equipment. They normally carry an eight-person crew and, when sweeping for the types of contact mines discovered in the gulf, fly at a speed of 10 to 12 nautical miles per hour, clearing a track about 250 yards wide on each pass.
To locate the underwater mines, the helicopters drag cables through the water with sonar devices attached to the ends. Crews aboard the helicopters can pinpoint the location of mines by watching a radar screen.
According to the Navy, the helicopters normally carry enough fuel to operate for 3 1/2 hours at a time. The Navy has 23 Sea Stallions equipped for mine sweeping.
Because no Persian Gulf state will allow the United States to operate the helicopters from bases on its territory, the C-5 transports will have to fly to Diego Garcia, a British island.
Because of space restrictions aboard the Guadalcanal, Navy experts believe that only four of the large Sea Stallions can operate from it at any given time.
Saudi officials said they have located seven mines since the Bridgeton was hit, and Pentagon spokesman Robert Sims acknowledged for the first time yesterday that additional mines were found near Farsi, an Iranian-controlled gulf island 120 miles south of Kuwait.