Important reference for new Cummins engine
Following delivery from a Spanish shipyard of two waterjet catamaran crew boats, Cummins has contracted Robert Allan Ltd to prepare drawings of its proven RAstar 3500 tug featuring the former’s new QSK95 marine diesel.
The IMO Tier II compliant new addition to Cummins’ stable has been in development for several years now and reported to have proved itself in high-speed applications and a good match for the RAstar tug design.
The high speed 1,800rpm engines each deliver 4,200bhp of power at just 13,282kg of weight, Cummins stating this is the same horsepower range that some recently delivered ocean towing tugs have been equipped with. With a length of 34.9m and combined 8,400hp these are by any measure large tugs and the engines will turn 3,200mm four-blade Kaplan azimuthing thruster propellers in nozzles via reduction of 8.476:1. Bollard pulls of 102t ahead and 96t astern along with a free-running speed of 14.2kn are predicted for this established design with the new machinery installations.
By Peter Barker