Renold Couplings are Only Choice for World�s Largest Cutter Suction Dredger



Renold Hi-Tec rubber-in-compression couplings are successfully operating in an environment that is about as tough as it gets in marine applications. They are working on the cutter drive of the largest cutter suction dredger in the world, the JFJ de Nul. Built by IHC Holland’s Kinderdijk yard, for Belgian contractor Jan de Nul, the JFJ de Nul has won the Netherlands’ prestigious Ship of the Year award from the Royal Dutch Union of Technicians in Shipbuilding.

The cutter on the JFJ de Nul can operate at depths of up to 35m and is ferociously powerful, being driven by two motors connected to a huge double-input gearbox, the largest in fact that has ever been made by manufacturer, Jahnel-Kestermann. The cutter can be driven by either one or two motors. Single motor operation is rated 3,800kW at 1,000rpm and twin motor operation is 2,500kW at 1,000rpm.

Renold Hi-Tec PM270 rubber-in-compression couplings, along with Wichita clutches, connect the motors to the gearbox. During operation the couplings have to deal with very high vibratory torques of a level that would cause rapid failure in most other coupling designs. The rubber-in-compression design also provides inherently failsafe operation, whilst damping the high shock loads.