The Story of NASA's Space Tracking Ships
During the 1950's and 60's the US converted a number of aging cargo ships into floating tracking stations to support the space program. These ships had been built quickly to support the US in World War II, and many had since been mothballed. About 20 of these would be converted to host multiple antennas and tons of electronics as well as mini versions of mission control which could operate independent of primary mission control if needed.
Manual for crew serving on board the Apollo tracking ships.