As Avondale Operations valve supervisor Bubba Thornton mounted and checked the 68 valves on Polar Endeavour, he set out to improve the process of installing and testing that many valves on such a huge ship. That's why Thornton joined 20 other Avondale employees to come up with a way to test the valves prior to installation aboard ship. There is a total of 68 valves, ranging in size from 8 to 36 in. in diameter, in the Polar tanker's cargo system. Of those valves, 31 control the flow of crude oil in and out of each tank during filling or discharging from land-based terminals. The other 37 valves control the movement of ballast water, potable water, ship's fuel and most of the other fluids in the ship's systems.