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J. Murawski and J. Woge Nielsen
time, fuel consumption and CO 2 emissions. Its main objectives are to reduce the
operating cost and to increase the efficiency of maritime traffic. Ship routing links
the ship’s position with its destination so that the travel time and costs are optimized
whereas the journey still remains safe and efficient. The quality of route analysis
and optimization depends critically on the forecast range of high-quality predictions. The choice of the best route might easily depend on the metocean conditions
10 days ahead. Winds, wind waves, swell, ocean currents and water depths are input
parameters for the performance calculations.
Vessels are monitored and in case of an alert, duty analysts develop course strategies and recommend course changes to meet weather conditions effectively, for example, to avoid heavy weather and critical ocean conditions like tropical cyclones,
deepening storms and freak waves. Each vessel is represented by an individual profile of construction and performance parameters: engine type and efficiency, friction
drag by the ocean and wind, main speed and fuel consumption. The design speed
of transport vessels is defined by its construction, but the optimum speed may vary
within a certain range. This allows certain adaptation strategies to market prices (low
rates–slow steaming) and fuel expenses (Ronen 1982, 1986; Molinero and Mitsis
1984; Evans and Marlow 1990). The optimum speed, often referred to as the economical speed, is most likely seen as the speed that maximizes profits, but route
optimization allows also to address green goals like emission reduction and consumption limitation. Route scheduling allows to assume economic and fuel saving
speed whenever there is time on a crossing. Up to 8 % fuel savings are reported.
In this context it is of large interest to compare the ‘performance’ of environmentally optimized fairways with similar evaluations resulting from commercial voyage
planning and weather routing. We shall compare the fairways designed above with
the ones derived using the software SeaPlanner, which is a cooperative development
of FORCE Technology and the Danish Meteorological Institute. As an onboard decision support system it links the operator at the DMI with the navigator on board
and provides necessary information for weather guiding and voyage optimizations.
Calculated routes are combinations of rhumb lines and great circle routes. They have
been optimized according to the total fuel consumption, minimum enroute time,
motor speed (revolutions per minute, RPM) and vessel speed for a fixed arrival time
(ETA) or with respect to the calm water speed.
Operational route predictions depend on frequently updated metocean forecasts
(every 6 hours), state-of-the-art optimization tools and advanced and flexible propulsion and propulsion plant models. The software includes resistance calculations
based on speed, draught-dependent still water resistance and additional components
for waves, shallow water and winds. A semi-empirical model calculates resistance
on the basis of the vessel’s ability for seakeeping (calculated and model tested efficiency to handle high sea states), shallow water friction (CFD calculated and model
tested drag parameterization) and the vessel’s wind friction drag (estimated from
a database of wind tunnel tests). Beside the resistance parameter, the propulsion
model includes a detailed description of propeller characteristics for fixed or controllable pitch and engine configurations. The software is able to distinguish between single and multiple engine set-ups, diesel electric propulsion, the use of a
Waste Heat Recovery system, and includes many other options.
J. Murawski and J. Woge Nielsen
time, fuel consumption and CO 2 emissions. Its main objectives are to reduce the
operating cost and to increase the efficiency of maritime traffic. Ship routing links
the ship’s position with its destination so that the travel time and costs are optimized
whereas the journey still remains safe and efficient. The quality of route analysis
and optimization depends critically on the forecast range of high-quality predictions. The choice of the best route might easily depend on the metocean conditions
10 days ahead. Winds, wind waves, swell, ocean currents and water depths are input
parameters for the performance calculations.
Vessels are monitored and in case of an alert, duty analysts develop course strategies and recommend course changes to meet weather conditions effectively, for example, to avoid heavy weather and critical ocean conditions like tropical cyclones,
deepening storms and freak waves. Each vessel is represented by an individual profile of construction and performance parameters: engine type and efficiency, friction
drag by the ocean and wind, main speed and fuel consumption. The design speed
of transport vessels is defined by its construction, but the optimum speed may vary
within a certain range. This allows certain adaptation strategies to market prices (low
rates–slow steaming) and fuel expenses (Ronen 1982, 1986; Molinero and Mitsis
1984; Evans and Marlow 1990). The optimum speed, often referred to as the economical speed, is most likely seen as the speed that maximizes profits, but route
optimization allows also to address green goals like emission reduction and consumption limitation. Route scheduling allows to assume economic and fuel saving
speed whenever there is time on a crossing. Up to 8 % fuel savings are reported.
In this context it is of large interest to compare the ‘performance’ of environmentally optimized fairways with similar evaluations resulting from commercial voyage
planning and weather routing. We shall compare the fairways designed above with
the ones derived using the software SeaPlanner, which is a cooperative development
of FORCE Technology and the Danish Meteorological Institute. As an onboard decision support system it links the operator at the DMI with the navigator on board
and provides necessary information for weather guiding and voyage optimizations.
Calculated routes are combinations of rhumb lines and great circle routes. They have
been optimized according to the total fuel consumption, minimum enroute time,
motor speed (revolutions per minute, RPM) and vessel speed for a fixed arrival time
(ETA) or with respect to the calm water speed.
Operational route predictions depend on frequently updated metocean forecasts
(every 6 hours), state-of-the-art optimization tools and advanced and flexible propulsion and propulsion plant models. The software includes resistance calculations
based on speed, draught-dependent still water resistance and additional components
for waves, shallow water and winds. A semi-empirical model calculates resistance
on the basis of the vessel’s ability for seakeeping (calculated and model tested efficiency to handle high sea states), shallow water friction (CFD calculated and model
tested drag parameterization) and the vessel’s wind friction drag (estimated from
a database of wind tunnel tests). Beside the resistance parameter, the propulsion
model includes a detailed description of propeller characteristics for fixed or controllable pitch and engine configurations. The software is able to distinguish between single and multiple engine set-ups, diesel electric propulsion, the use of a
Waste Heat Recovery system, and includes many other options.