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64 Maritime Reporter & Engineering News • SEPTEMBER 2014 PROPULSION UPDATES W hile the marine industry is rife with rough working conditions, dredg- ing operations arguably pose the toughest challenge to any class of marine equipment. Water lubricated Thordon Composite cutterhead shaft bearings have re- portedly performed well for nine years on one of the largest cutter suction dredgers in the world – Dredging, Environmental and Marine Engineering N.V. (DEME)’s D’Artagnan (28,200 kW total in- stalled power). The vessel had a major dry docking at Drydocks World-Dubai in February 2014 where the shaft was removed, and bearings and shaft inspected. Origi- nally built in 2005, the D’Artagnan self-propelled cutter suction dredger is involved in heavy rock- breaking having a cutting power for operations in rock soils of 6000 kW. “The bearings performed well and have shown a positive wear life compared to grease lubricated metallic bearings,” said Frederik Mertens, As- sistant Vessel Manager at DEME. The decision was made to replace the cutterhead shaft bearings. The same Thordon Composite bearings are also in- stalled on the intermediate ladder shaft bearings. Mertens says, “For the intermediate ladder bear- ings we noticed even less wear on the Thordon bearings than the cutterhead bearings so we did not replace them.” Grease-free Thordon SXL wire rope sheaves were also installed during the drydocking. Thordon’s authorized Distributor in the U.A.E., Ocean Power International (OPI), assisted Dry- docks World and Dredging International (DEME’s subsidiary) in the replacement with additional su- pervision during, and prior to, installation. The inspected bearings confi rmed that the Thor- don Composite grade can withstand the most abra- sive conditions typical for a dredger equipped for working in various mediums. “Compared to ex- pensive bio-degradable greases, these water lubri- cated bearings from Thordon are a real cost saving alternative,” said Mertens. Dredger: 9-Year Wear Life on Cutterhead Shaft Bearings Thordon Composite cutterhead shaft bearings prior to installation on the D’Artagnan owned by DEME MR #9 (58-65).indd 64 9/4/2014 11:28:55 AM
