11 Applications of an Oil Drift and Fate Model for Fairway Design
399
similarly and would give operators the possibility to choose an optimum solution.
But these ideas seem to be out of the scope of currently realizable solutions.
The pool of fairways to Saint Petersburg (not shown) is unique in the sense that
their length is rather similar, although they cover nearly the entire width of the gulf.
Ship performance in terms of travel time, speed and fuel consumption is therefore
not simply a measure of the length of the crossing, but is determined by water depth
and metocean conditions. The fastest route is provided by the route atlas (RA), combined designs (CMB) and the SeaPlanner optimization routines (SPO), which outperform most of the other candidates in terms of fuel consumption as well. Performance variations are the results of the strong River Neva outflow and the dominant
wind directions that generate heterogenous metocean conditions and have a strong
impact on the shipping conditions in one direction or another.
Whereas westward going cruises favour more northern fairways to use the advancing power of the River Neva outflow, eastward going cruises prefer southern
fairways to avoid it. SeaPlanner optimization adapts to the situation and produces
different sets of fairways for eastward and westward going cruises. For the analysis,
they serve just as reference value. Leaving them aside, the fairways from the route
atlas and combined designs are competing for the top economical performance, the
first being better on westward going cruises and the other being better on eastward
going ones. From an economical point of view it would make sense to keep the
twofold set of routes, because comparisons with SeaPlanner optimized fairways
(SPO) show that performance could be gained by moving RA and CMB routes even
further apart (RA routes should be moved northwards and CMB routes southwards).
From the viewpoint of performance, the open sea fairways SPO, RA and CMB
are superior to more coastal fairways such as SW and SA (Table 11.3). That surprises at first because the SW design follows the River Neva outflow more clearly
than any other design. The low performance can be explained by the lower water
depth and increased shallow water resistance that has been taken into account by
the ship propulsion model but was ignored in the SW and SA design. An evidence
for the positive impact of the River Neva outflow on west going cruises is provided
by the fact that the SeaPlanner optimized route, which follows the northern SW design but stays more offshore, is the fastest route with the lowest fuel consumption.
Analysing the consumption parameter for a fixed travel time of 13 hours eastto-west provides a consistent picture. The SeaPlanner optimized route (SPO), following the River Neva outflow, is reaching the time goal with the lowest required
average speed and fuel consumption.
Vyborg is an important harbour for oil transportation in the Gulf of Finland. The
fairways that connect its premises to the Baltic Proper 4 use three different sets of
routes. The first and shortest route follows the SW designs and runs along the northern shore of the Gulf of Finland in a direct line to Vyborg. Although by far the
shortest route, it is also by far the most uneconomical one. Shallow water resistance
in near coastal waters is again rendering it inefficient, pushing engine load and fuel
4 This notion is used here to denote the Eastern, Northern and Western Gotland Basin, Bornholm
Basin and Gda´ nsk Bay (cf. Chap. 2, Fig. 2.1).
399
similarly and would give operators the possibility to choose an optimum solution.
But these ideas seem to be out of the scope of currently realizable solutions.
The pool of fairways to Saint Petersburg (not shown) is unique in the sense that
their length is rather similar, although they cover nearly the entire width of the gulf.
Ship performance in terms of travel time, speed and fuel consumption is therefore
not simply a measure of the length of the crossing, but is determined by water depth
and metocean conditions. The fastest route is provided by the route atlas (RA), combined designs (CMB) and the SeaPlanner optimization routines (SPO), which outperform most of the other candidates in terms of fuel consumption as well. Performance variations are the results of the strong River Neva outflow and the dominant
wind directions that generate heterogenous metocean conditions and have a strong
impact on the shipping conditions in one direction or another.
Whereas westward going cruises favour more northern fairways to use the advancing power of the River Neva outflow, eastward going cruises prefer southern
fairways to avoid it. SeaPlanner optimization adapts to the situation and produces
different sets of fairways for eastward and westward going cruises. For the analysis,
they serve just as reference value. Leaving them aside, the fairways from the route
atlas and combined designs are competing for the top economical performance, the
first being better on westward going cruises and the other being better on eastward
going ones. From an economical point of view it would make sense to keep the
twofold set of routes, because comparisons with SeaPlanner optimized fairways
(SPO) show that performance could be gained by moving RA and CMB routes even
further apart (RA routes should be moved northwards and CMB routes southwards).
From the viewpoint of performance, the open sea fairways SPO, RA and CMB
are superior to more coastal fairways such as SW and SA (Table 11.3). That surprises at first because the SW design follows the River Neva outflow more clearly
than any other design. The low performance can be explained by the lower water
depth and increased shallow water resistance that has been taken into account by
the ship propulsion model but was ignored in the SW and SA design. An evidence
for the positive impact of the River Neva outflow on west going cruises is provided
by the fact that the SeaPlanner optimized route, which follows the northern SW design but stays more offshore, is the fastest route with the lowest fuel consumption.
Analysing the consumption parameter for a fixed travel time of 13 hours eastto-west provides a consistent picture. The SeaPlanner optimized route (SPO), following the River Neva outflow, is reaching the time goal with the lowest required
average speed and fuel consumption.
Vyborg is an important harbour for oil transportation in the Gulf of Finland. The
fairways that connect its premises to the Baltic Proper 4 use three different sets of
routes. The first and shortest route follows the SW designs and runs along the northern shore of the Gulf of Finland in a direct line to Vyborg. Although by far the
shortest route, it is also by far the most uneconomical one. Shallow water resistance
in near coastal waters is again rendering it inefficient, pushing engine load and fuel
4 This notion is used here to denote the Eastern, Northern and Western Gotland Basin, Bornholm
Basin and Gda´ nsk Bay (cf. Chap. 2, Fig. 2.1).