Caterpillar Marine has unveiled its Cat Marine Hybrid Thruster system that it claims improves fuel economy by up to 35% and increases life savings for offshore support vessels (OSVs).
This new propulsion offering outperforms diesel mechanical systems in all partial load conditions and for vessels that spend a high amount of time in standby or DP service, says Cat. The annual fuel savings have been reported as being as high as 35% across the entire operating profile of a vessel.
The idea behind the Cat Marine Hybrid Thruster system is to reduce overall cost to vessel owners and to optimise operation as much as possible. As OSV’s spend a large amount of time in standby or in varying levels of Dynamic Positioning (DP) mode, the new system enables them to use the diesel electric mode and run off smaller gensets with the propellers operating at a very low rpm for maximum economy.
The thruster system could be used to downsize a ship’s main engine to optimise engine load, while allowing the vessel to switch to diesel electric mode for Dynamic Positioning (DP) operations or in standby.
In transit operations and in diesel-mechanical mode, smaller engines run at higher loads, consuming less fuel. In low-speed transit, either one or two gensets can power the main azimuth thruster in diesel-electric mode giving typical fuel savings of 10-15% at speeds in the 7-9 knots range, depending on hull profile. The largest savings are made during standby and DP operations where the vessel would operate in diesel electric mode with the main azimuth propellers running in the most efficient variable speed mode.
Furthermore, the booster motors and drives are controlled directly from the Caterpillar control system which also performs all mode selections, interfaces with the vessel’s Planned Maintenance system (PMS) and provides a single point interface for the operator.
The system can be retrofitted to existing ships or applied to newbuilds. The exact savings depend on the ship service, type and size.
The first system is to be delivered to an undisclosed ship yard in Singapore and will be commissioned mid this year.
Ship Efficiency Review News
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