International Dredging Review

International Dredging Review

Dredging Supply Company Inc. delivered a 14-inch electric Marlin cutterhead dredge to Martin Marietta Noldesville Indiana in late 1999. Martin Marietta is using the new dredge to mine sand and gravel and it has been operating successfully since its installation said a company representative.

The dredge is an all-electric dredge with no hydraulics in the lever room which allows the Marlin to meet MSHA noise level ratings. A key benefit of the clean-running dredge is that is can run longer with low maintenance requires no fuel and is environmentally friendly said Tommy Wetta DSC vice president.

In lieu of the standard line-shaft pump drive that uses water-lubricated bearings the Marlin uses a dynamically balanced torque tube drive in conjunction with the sealed intermediate bearing tube. This tube is sealed and has roller bearings running in an oil bath which results in lower maintenance and less downtime.

The control system uses a Programmable Logic Controller (PLC) and computer controlled console. Martin Marietta chose this option to monitor operating conditions and provide daily reports. The computer console interface is customizable to meet the wide range of dredging industry needs. In addition martin Marietta purchased the dredge production package that can be used to generate daily production reports on a “per ton” basis providing real-time access to production directly in the lever room.

Other options the company chose are an operator-controlled power cable reel. They also added a jib crane and trolley system for easy removal of dredge pump components and an air-conditioned lever room and machinery enclosure. The enclosure included an electrical/hydraulic partition for fire protection. Because of the extra security at such a reasonable price many DSC customers are choosing this option said Wetta.

The new dredge includes a Christmas tree which is a stern three-wire positioning system that allows the dredge to dig hard material by holding the stern of the dredge in a fixed position. The forward location of the lever room means that no hearing protection is required and the room meets MSHA noise level requirements.

DSC is located in Harahan Louisiana and designs and builds dredges for delivery throughout the world.