DOP Pump 250 with sand production head & leveller head 1 DOP for sand mining, 2 DOPs for hopper discharging. Three DOP dredge pumps have been installed on a split hopper. One DOP250 will mine sand at -20 m using its jetwater assisted mining head. The other two submersible dredge pumps will empty the hopper, discharging the mined sand some 400 m on shore. See all deliveries