Weather profits In-depth | OPERATIONS
A voyage optimisation package from Jeppesen based on thinking derived from naval architecture is making waves.
voyage optimisation package draws heavily on naval architecture, while at the same time offering the type of up to the minute functionality demanded by users more familiar with the products marketed to airline customers by its parent group Boeing. While bunker fuel prices today are
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lower than was the case this time last year, prices are on the rise again. Thus, cost and schedule-conscious shipowners must put in place the means of optimising vessel passage and routing. Jeppesen has achieved some success
in supplying its voyage optimisation solutions, with around 200 ships using the system to date, mainly in the deepsea container and reefer trades. Now, the company is ready to take its offering to a wider market. Thomas A King, Jeppesen Marine‘s
senior business development manager, marine operations, said that the company’s VVOS (vessel and voyage optimisation solutions) used statistical analysis of a vessel’s past voyages to deliver advice to shipowners on how they might adjust routing or performance parameters during a current or coming voyage. VVOS offered ship-specific modelling and calibration, and a proprietary optimisation process that measured optimal speed management against constant speed, on which a patent was pending. Mr King said that, in general,
Jeppesen analysis had shown that ship efficiency was “in the low 90% range” when considered in terms of the optimum possible means of getting from A to B. Using VVOS, owners to date had found that they could improve vessel performance to “around 96%-97%”. VVOS analysed ship performance
based on as many as 100 voyages of a ship or class of ships, to establish how that ship performed in the context of
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VVOS voyage optimisation package from Jeppesen Marine shows a range of voyage options to meet the same objective of getting from A to B.
whether it arrived on time, how much fuel it consumed, whether it operated safely at all times, or by any other parameter set by the shipowner. VVOS uses algorithms based on seakeeping and hydrodynamic performance to record the efficiency of the ship. Roll, pitch and acceleration forces can all be accounted for, and the system can even be programmed to gauge the effect heavy weather will have on hull stress and cargo damage, if the shipowner identifies this as something to be avoided in order to maintain the integrity of the asset. In detail, the system collects past
passage reports from the ship’s engine and deck logs, cumulatively tracking passages in different weather conditions. It then develops and calibrates baseline performance models for the hull, propeller and engine against actual recorded values, and simulates the passages using ‘hindcast’ wind, wave and current data, going on to compare fuel consumption to the optimised passage for the same ETD and ETA. Statistics can then be compiled showing results before and after adopting VVOS.
The ‘hindcast’ is a means of normalising external environmental conditions post-voyage. A sensor is mounted in the wheelhouse
to record vessel motion information, with the VVOS also interfacing with the GPS onboard, ECDIS, and the automation and machinery system. including the engine or even with the cargo loading system. Thus, with thrust, fuel consumption, wave height, wind speed, ship speed, draught and trim all measured or observed, propeller and engine efficiency - or their degradation - and the effect of hull fouling can be calculated. The system uses proprietary
algorithms to offer advice on the way to minimise fuel consumption for a range of arrival times within ‘user-set safe operating limits’, and to offer en-route tactical guidance for ETA, fuel optimisation and safe seakeeping. A ship’s operating area could also
be defined by ice coverage, insurance needs, navigation safety, expectation of attack by pirates, etc, with all of these factors feeding into the expected time
The Naval Architect July/August 2009
arine cartography specialist Jeppesen Marine says its latest weather routing and
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