Evaluating Calculated Routes - Simrad Maris ECDIS900 Operator's Manual

Evaluating calculated routes

VDS calculates the fuel consumption and sailing time along the shortest track i.e. the track
defined by great circle legs.
R
OUTES DATA
Two routes have been calculated for the next voyage called "Atlantic":
LDR_01_Atlantic is the shortest route using great circle le, calculated using the Great
•
circle option
LTR_02_Atlantic is the fastest and best economical route, calculated using the least time
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route option.
The results of the calculation are given in table:
Dist: the distance of the each calculated route
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Departure time. Same departure time for this calculation
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TTG is the total sailing time for each route, 8h difference between the two options.
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STW is the planned speed
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Speed loss is difference between the planned speed and the calculated SOG for each
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option due to the effect of the waves, wind and current. In the example the Speed loss for
the shortest route LDR_01_Atlantic is 2.13 kn meaning that the SOG along this route
should be 12.87 Knots for a 15 Knots planned speed.
ETA is the estimated time arrival for each route
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Fuel is the consumption for each route. In the example the LTR_02_Atlantic is the most
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economical route of the calculation as the ship may spend 35 Tons less fuel than with the
great circle route
Fuel cost gives indication of the cost of each option.
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VALUATING CALCULATED ROUTES