Tanker fill sites can be supplied using a number of different methods - the "open relay" being one of them. The concept of an open relay is simple - some type of pumping device (or eductor) flows water into some type of open container (like a dump tank) and a pumper takes suction from the container and fills tankers. Generally, this arrangement is used when the pumper cannot get close enough to the static water source to draft and it most always involves the use of some type of lower rated pumping unit like a portable pump.

It is important to keep in mind that the performance goal for a tanker fill site is at least a 1,000 gpm fill rate simply because that rate is the minimum design standard for tankers built in compliance with the current edition of NFPA 1901.

The premise of the open relay that we present in this News Story is that a smaller pumping unit can access the water and pump back to the dump tank where the full-size pumper will draft and fill tankers at 1,000 gpm. In most cases, with a little practice this operation works quite well - the key is to use the largest dump tank that you can get your hands on at the fill site - this will provide a nice reservoir from which to operate.

The photos in this News Story are from our August 2013 rural water supply seminar in Ottawa, Kansas. Crews used a large pond at a church camp as the sole water source for the drill. The 400 gpm brush truck drafted and pumped into the 2,500-gallon dump tank from which the 1,000 gpm pumper drafted and filled tankers. At no time did the dump tank ever go dry during the drill.