We have 2 pumper/tankers that we do utilize the pump to move the water into the dump tank. It works very well for us. We also use this method with our main tanker which has a front mount pump on it. It also has an electronic dump chute in the rear.
In pump to dump we are able to fill a fold-a-tank through the pump on the engine while fire operations are under way. When the Tanker is empty it can disconnect and we can continue pumping with the water in the fold-a-tank. It can also be used to fill your engine tank at the same time. Very efficient.
We are currently using 2- 3" lines for this and are planning on moving up to 1- 4" to accomplish the same result. With the 2 lines we can offload 2 tankers at once. We will still be able to do this with the 4" buy using a gated Y.
The advantage to this is multiple tankers can pump through you at the same time. We have narrow long driveways here that make tanker ops very difficult. As you know many times getting a tanker to the fold-a-tank can be almost impossible at times. This system works very well and can maintain a steady fire flow and keep your water storage full at the same time. We operate in a Rural area with very few hydrants in the district.
We train on this constantly to keep our crews proficient. The advantage here is you are receiving water through the EYE of the pump. Excess goes into the fold-a-tank through your suction hose. when the tanker shuts down and disconnects the flow reverses and automatically you are drafting out of the fold-a-tank.
Well done! Maximizing rural water supply is almost an art form. When you realize the pump intake manifold is a hollow metal box then intakes can become discharges. That hard suction line is either an intake or a discharge. Now try filling another drop tank by siphoning through the intake manifold. Keep in mind also that you can receive water from multiple vehicles through multiple ports in the intake manifold. Have you ever tried drafting from the drop tank while also receiving from the tender? If say you wanted the deck gun at 1,250gpm for a quick knock down but the tender was only supplying 500 gpm? Not possible without collapsing the tender’s hose? It’s possible, almost easy ;-)
We are able to receive and pump at the same time. We just upgrade our main engine to 4"LDH, 1150' with STORZ fittings. We have a triple Siamese that we can hook up to 3 tankers at a time to. We run water back and forth to extra fold a tanks with jet lifts.
A problem we did run into on our hard suction with STORZ fittings is that you need dual suction gaskets on them or they will suck air. Our Department has 2 tankers, a 2000gal and a 4000 gal. We also have available another department with 2 2000 gal. tankers and several independent water haulers with 4000 gallon trucks.