OC series were all "one off" conversions of various naval ships into floating test vessels. Most were converted from old minesweepers and amphibs for various research purposes (torpedoes, missiles, radars, sonars, lasers, etc).
There were more than 60 of them at various times. No specific design, all of them ad hoc conversions.\
Saw this story earlier and was relating it to my Dad.
He used to run across, shadow and board SIGINT trawlers in the Bering Sea in the early 60's
I said "Dad! Some of them might have had torpedoes!"
He said "Boy, I doubt those drunken c*nts could have found their own ass with both hands and a road map, let alone the launch button for a torpedo"