Description Operation End Sweep was a United States Navy and United States Marine Corps operation to remove naval mines from Haiphong harbor and other coastal and inland waterways in North Vietnam between February and July 1973. The operation fulfilled an American obligation under the Paris Peace Accord of January 1973, which ended direct American participation in the Vietnam War. It also was the first operational deployment of a U.S. Navy air mine countermeasures capability.
Task Force 78 was activated as a unit of the Seventh Fleet on 24 November 1972, while peace talks still were underway in Paris, and the ships and helicopter units making it up secretly gathered in the Philippines. The talks broke down in December 1972, however, so the task force awaited further developments into January 1973 while its helicopter crews practiced towing their minesweeping equipment in Subic Bay off Luzon.
On 28 January 1973 – the day after the peace accords were signed in Paris – Task Force 78 departed the Philippines for Haiphong. McCauley met in Haiphong with his North Vietnamese opposite, Colonel Hoang Huu Thai, on 5 February 1973 to coordinate North Vietnamese actions with those of Task Force 78.
Minesweeping began on 6 February 1973, when the ocean minesweepers USS Engage (MSO-433), USS Force (MSO-445), USS Fortify (MSO-446), and USS Impervious (MSO-449) swept coastal waters near Haiphong, protected by the guided-missile frigate USS Worden (DLG-18) and destroyer USS Epperson (DD-719). On 27 February 1973, the amphibious assault ships USS Tripoli (LPH-10), USS New Orleans (LPH-11), and USS Inchon (LPH-12) and the amphibious transport docks USS Dubuque (LPD-8), USS Ogden (LPD-5), and USS Cleveland (LPD-7) joined the task force, carrying the 31 CH-53 Sea Stallion helicopters of HM-12, HMM-165, and HMH-463. The helicopters swept the main shipping channel to Haiphong the same day. The next day, however, President Nixon ordered a suspension of End Sweep in response to North Vietnamese delays in releasing prisoners-of-war.
End Sweep resumed on 6 March 1973. On 9 March 1973, a mine exploded – the only one to explode during End Sweep – as a minesweeping helicopter passed it and the explosion was captured on film by the helicopter's Swept Mine Locator. On 17 March 1973, Task Force 78 helicopters swept the ports of Hon Gai and Cam Pha. Elsewhere in North Vietnam, U.S. Navy technical personnel prepared 50 North Vietnamese sailors to conduct their own minesweeping operations and American C-130 Hercules transport aircraft delivered minesweeping gear to the North Vietnamese at Cat Bi Airfield outside Haiphong.
The special device minesweeper USS Washtenaw County (MSS-2) making her final check sweep in North Vietnam's Haiphong Harbor on 20 June 1973. A single-masted junk under sail is at right.
Washtenaw County arrived at Haiphong from the Philippines on 6 April 1973, and made her first six check runs there on 14 April 1973, the first American ship to enter Haiphong harbor in over a decade. She had made only two out of a planned six runs the following day when further runs were suspended because the United States believed that the North Vietnamese government was not fulfilling its obligations under the Paris Peace Accord. Washington ordered a suspension of all minesweeping operations and, on 17 April 1973, Task Force 78 returned to Subic Bay for upkeep.
On 13 June 1973, the United States and North Vietnam signed a joint communiqué in Paris which, among other things, required that the United States resume minesweeping no later than 20 June and complete all minesweeping no later than 13 July. With all mines by now past their latest possible sterilization date, End Sweep resumed on 18 June 1973. On 20 June, Task Force 78 completed its check sweeps of Haiphong, and soon had also cleared Hon Gai and Cam Pha. Next, the task force concentrated on the coastal areas off Vinh. The final minesweeping operations took place on 5 July 1973 and the next day, Rear Admiral McCauley informed the North Vietnamese that the United States had concluded its mine countermeasures operations in North Vietnamese waters.
Operation End Sweep ended officially on 27 July 1973, and Task Force 78 withdrew from North Vietnamese waters the following day.
