Upgrading the propulsion system on shipping vessels to a Wartsila Australia HR nozzle can lead to remarkable fuel savings. The large increase in oil prices of the last years has lead to a lower profitability of many fishing fleets. Depending on the operational profile of the vessel, the fuel costs can be as large as 20% to 30 % of the catch. Therefore ship owners are constantly seeking different ways of reducing fuel consumption in order to remain profitable.
Most modern fishing trawlers are now fitted with with a Wartsila propeller and an HR nozzle. For example, small trawlers are in general fitted with a fixed pitch propeller, while the higher-powered vessels use a controllable pitch (CP) propeller. A typical mission profile of fishery vessels is characterised by several dominating operating conditions; steaming, searching for fish and trawling and depends on the type of fish they are catching and also the region where the vessels are operating.
The optimisation of the propeller diameter and shaft speed can be evaluated to see if further efficiency improvements are possible. Benefits of using the Wartsila HR nozzle include the following:
* The HR nozzle offers more efficient propulsion system
* At low speeds the delivered pull of a propeller running in an HR nozzle can be 40 % larger compared with an open propeller
* The HR nozzle shows over the whole speed range up to 12 knots, anything from 6 to 10 % higher fuel efficiency
* Above that range, the HR nozzle outperforms even more
* A total efficiency gain of 20-30% can be achieved when converting from an open propeller to a HR-nozzle
* Efficiency gain of 6-10% can be achieved when converting from standard nozzle to HR-nozzle
According to Mr. John Sydney, Managing Director / General Manager Service Sales , this application has many other maritime uses. “This type of technology can be applied to just about any sea-going vessel currently in service today, including tugboat, barges and even some naval vessels”, he says. “Its all about better utilizing the available power whilst cutting fuel costs at the same time, notes Mr. Sydney, adding that, “and who doesn’t want to save money on operating costs these days?”