Pit & Quarry, March 2010

D R E D G I N G dredge horizontally without lifting the spud The unit maintains three diesel engines with the prime mover being a 1000 hp Cat engine and the hydraulics are powered by a 500 hp Cat engine Dredging Supply Co supplied the controls package Its production meters include the integration of a nuclear mass meter and an ultrasonic flow meter that monitors the vacuum that the dredge is pulling the velocity in the pipeline the number of tons per hour and the density of the product Using EIW classifying tanks fine mesh particles are more easily retained to meet tight construction sand specifications stream that is being pumped to the plant To take the guesswork out of dredging ARMCO outfitted the dredge with a Trimble HydroPro GPS system We have a laptop in the dredge that is running the Trimble software It allows us to track the location and orientation of the cutterhead We can then track where we have been and to what depth we have dredged so that we can remain efficient Stroup says The dredge was also designed with maintenance ease in mind Stroup says that most wear parts are rubber or abrasionresistant metal or rubber coated metal We wanted as much time between maintenance overhauls as possible as it is very time consuming to bring the dredge to shore he says Material flow Material is pumped from the dredge to the top of the plant through a 20 in poly pipeline in which material travels 1000 ft to the plant at 10000 gallons per minute The volume of material that were pumping depends on how fine it is and whether the cutterhead is buried or not Our goal is to be at 20 PIT QUARRY March 2010 www pitandquarry com