MSO-488: Minesweeper in Haiphong Harbor

My Viet Nam service began when it was decided to mine Haiphong Harbor. I was XO of USS Assurance (Minesweeper Ocean, MSO-521) in Charleston. We were sent to Hampton Roads in September 1972 to help determine the best method for sweeping the Mk 36 Destructors that the Navy planned to use. Fast forward to January 1973. As part of the peace process, Henry Kissinger agreed to sweep the mines that we had dropped. Two of the sweeps chosen to do the job were Naval Reserve Force at Pearl Harbor. As they had reduced active duty crews, volunteers were needed to fill the vacancies. I volunteered, and in late January was on a plane with half an MSO crew flying to Hawaii.

We joined USS Conquest (MSO-488) in the middle of a mini-yard overhaul, did a brief refresher training, then commenced our 5800 mile trip west in company with USS Esteem (MSO-438) and USS Moctobi (ATF-105). After a stop in Guam where we were dry docked for a bottom cleaning, we headed for Subic Bay, Philippines, where we joined more of the Operation End Sweep task force.

In late March we headed for Haiphong. As we went west, USS Force (MSO 445) was heading east, her trip cut disastrously short by a fire that burned the wooden ship to the waterline. We took fire drills seriously after that. We reached the contiguous waters of Viet Nam on 3 April, only to find out that Congress, in its inimitable wisdom, declared the war over on 30 March. Hence, we received no Viet Nam service decorations, something that has irritated me to this date!

For the next 5 months we helped with the sweeping . The MSOs did no actual sweeping, but rather acted as air traffic controllers, directing the MH-53 helos as they towed mine sweeping sleds and MOPs (magnetic orange pipes)back and forth over pre-designated tracks. Very few mines, perhaps only one, were exploded, the rest having gone dormant.

Depending on how the negotiations were going in Paris, we’d sweep, return to Subic and sit, then back to Haiphong to sweep, and back to Subic and sit. For excitement, we got to experience Typhoon Anita in the South China Sea, our 172 foot long round bottomed wooden boat taking a 47 degree roll!

Eventually we were detached from the Haiphong sweeping and sent to the Strauss-Warrington area down the coast, where the 2 destroyers of those names were damaged by underwater explosions of undetermined origin. The explosions were rumored to be mines dropped by our A-7s returning to their carrier with mines they had failed to drop in Haiphong.

In late September we were detached and made the 5800 mile trip back to Pearl. So while it can be argued that I didn’t do any VN service since the war was over (see para 3), Saigon didn’t fall for another 19 months. That and the 5 plus months I spent in WestPac cause me to disagree.

Interesting anecdote: When Conquest got to Guam, who should I meet in the O Club but a Tulane ROTC classmate/fraternity brother (supply type). Then at Subic, another Tulane classmate (a Marine infantryman). Then on a visit to Cubi Point, another Tulane classmate (an A-6 pilot). Small military world.

Robert Michael Cosgrove graduated in 1968 with BSME. He served in the USN 1968-1993 with time in Vietnam during 1973.

Commands and Locations:

USS Assurance (MSO 521), Charleston, SC

USS Conquest (MSO 488), Pearl Harbor