DOP Submersible Dredge Pump 450L "Cashman" A large J. CASHMAN excavator is fitted out with a DOP450L, the largest DOP submersible dredge pump available. The DOP450L is used to empty barges. A number of barges, each containing some 3.600 m3 of sand, continuously transport sand from the winning location to the barge emptying spot. There, the sand is pumped out of the barges by the DOP450L, and delivered to a spoil field 800 m further. See all deliveries