We are providing a Mud Tank which is an open-top container, typically made of steel, to store drilling fluid on a drilling rig. They are also called mud pits, because they used to be nothing more than pits dug out of the earth. The tanks are generally open-top and have walkways on top to allow a worker to traverse and inspect the level of fluid in the tanks. The walkways also allow access to other equipment mounted on top. Recently, offshore drilling rigs have closed-in tanks for safety.