From what I Have read the oil platform was "state of the art" and GPS controlled. It was a free floating rig with no moors, and thrusters that triggered off GPS kept it centered. It was suppose to be cutting edge in rigs, with capabilities of drilling at water depths of up to 18,000 feet. The REDUNDANT safeties obviously failed as did the manuals. Kinda like a couple of space shuttles as I recall. BP was LEASING the rig, and it had already been set up by an owner company whom then leased it to BP. Operating costs were in excess of a little more than $1,000,000.00 per day.