Large drilling rigs have an area sometimes referred to as a "cellar" positioned directly under them. The cellar is a 40.times.50.times.60 foot space in which are positioned blow out preventers, pumps and other equipment. The height of the equipment configurations is such that great care must be taken during servicing. A fall from the equipment can kill or severely injure a worker. These large drilling rigs are located at one drilling site for approximately one year, and during that time period servicing is inevitably required.
With most drilling rigs, drilling fluids leak down from the drilling rig floor into the cellar. With large drilling rigs this is totally unacceptable, due to the safety hazard it creates. For this reason, large drilling rigs are presently being manufactured with large "catch pans" welded to the underside of the drilling platform under the rotary table. The catch pan catches drilling fluids from the drilling rig platform and direct them into a sump. The contents of the sump are periodically pumped out by a tank truck and hauled away. It will be understood that the use of a catch pan both addresses the safety concern described above and provides a secondary benefit of reducing the amount of environmental contamination at a drill site.