During our 2010 rural water supply seminar in Deer Creek, Illinois we came across Tender 5 from the Mackinaw Fire Protection District. The rig carries 3500-gallons of water and is equipped with an 800-gpm PTO driven fire pump. Perhaps the most unique feature is the 12-inch round rear dump. Of special note, is the manner in which the large butterfly valve is controlled. The valve's control handle was modified so that the operator can stand next to the vehicle and not behind the vehicle when opening and closing the valve. While we don't have any official times regarding the tender's ability to dump, we do know that there clearly was no issue dumping water! Using a strict, cross-sectional area evaluation approach, a 12-inch round dump has about 113 square inches of cross-sectional area through which was can move whereas a 10-inch square dump has 100-square inches of cross-sectional area.