The Aggressive was the lead MSO ship and as such was subject to rigorous testing.......
In late 1955, Aggressive participated in underwater explosive tests to determine the degree of damage to be expected from a mine explosion close aboard. Information obtained from these tests was used to improve the design of planned minesweepers and to make the required alternations to those already in commission. At completion of these tests, Aggressive entered a shipyard for additional design modifications and necessary repair work, which were completed in August 1956.1
The Aggressive went underwater explosive testing in Key West. When I went aboard in '59, the machinery history records were full of damage reports that just about wrecked the entire engineering plant during the test. All the main engines were knocked off their mounts, the engine on the 300KW variable frequency generator was rolled over on it's side. I think the only machinery that was operable after the test was the 60KW, and 100KW generators, which were contained on their own engine mounts.
I heard that the crew was removed, and explosive charges were detonated under the ship, and literally lifted her out of the water. This happened in the mid 50's, and required a complete shipyard overhaul afterward. There was little hull damage, but major machinery derangement.
1 Excerpts from David Bruhn's draft manuscript of his work in process.