400
J. Murawski and J. Woge Nielsen
consumption to the highest, and developed average speed to the lowest level. The
best fairway designs combine short distance with sufficiently deep water and low
hull friction. The second set of routes for the candidates (SA, CMB and the established fairway RA) partially achieves this by following the gulf’s axis until passing
by the island Gogland (see Fig. 10.2 in Chap. 10) in the south. Although staying
offshore all the time, their performance is reduced by the length of the crossing. The
‘winning’ one is the SeaPlanner optimized fairway that runs through the northern
part of the gulf and passes by Gogland in the north. This route is shorter, which
results in shorter travel times and lower fuel consumption, by even lower or comparable average speed. It is worth mentioning that the optimal SPO routes are identical
for the east- and westward crossings. The results are therefore uniform and consistent.
The example of routes to Vyborg and Saint Petersburg demonstrate that it is
probably impossible to find an optimum solution that would fit for all harbours,
ships, and constraints. The performance analysis shows that a northward shift of the
Vyborg route (passing by Gogland in the north) would improve travel time and fuel
consumption measurably. On the other hand, such a shift would separate the Vyborg
route from the Saint Petersburg route and would generate a decomposed system of
fairways. Optimization is configuration dependent and pursues individual solutions
for small or single-member networks with higher efficiency. This becomes apparent
for harbours like Sillamäe and Ust-Luga. The established network with its tree-like
structure, from which the different routes branch off, forces the maritime traffic to
take uneconomical detours with up to 25 nm longer fairways, which amount to about
15 % of the length.
The port of Ust-Luga is situated in Luga Bay in the south-eastern part of the
gulf. Although most of the fairway designs choose for economical reasons a more
or less direct route out of the bay and towards the west, the route atlas orders vessels
to take a detour to the north, to meet the Saint Petersburg fairway. This amounts
to about 2 hours additional travel time, and more than 1 metric ton (mt) more fuel
consumption, which is significant for the relatively small distances along the Gulf of
Finland. The existing fairway, as specified by the route atlas, is about 25 nm longer
than any other fairway. As this fairway is situated in the southern part of the gulf, its
performance is not much affected by the River Neva outflow. The path length and
integrated effects of the shallow water resistance are again the main performance
limiting factors.
It is not surprising that near coastal fairways, which are most favoured by SA
designs, are strongly affected by shallow water hull resistance. Other fairways show
quite small performance variations. The best solution is provided by the SeaPlanner optimization routines, which feature short distances and courses that directly
target the Baltic Proper. The optimized Ust-Luga fairways are mainly defined by
geography and are identical for eastward and westward crossings.
The port of Sillamäe is situated in north-eastern Estonia. Its connection to the
Baltic Sea fairway network also runs along the Saint Petersburg line, which meets
the Sillamäe fairway near Gogland. The existing RA route is on average about 11 nm
longer than the alternative designs, which amounts to up to 1 hour longer travel time
J. Murawski and J. Woge Nielsen
consumption to the highest, and developed average speed to the lowest level. The
best fairway designs combine short distance with sufficiently deep water and low
hull friction. The second set of routes for the candidates (SA, CMB and the established fairway RA) partially achieves this by following the gulf’s axis until passing
by the island Gogland (see Fig. 10.2 in Chap. 10) in the south. Although staying
offshore all the time, their performance is reduced by the length of the crossing. The
‘winning’ one is the SeaPlanner optimized fairway that runs through the northern
part of the gulf and passes by Gogland in the north. This route is shorter, which
results in shorter travel times and lower fuel consumption, by even lower or comparable average speed. It is worth mentioning that the optimal SPO routes are identical
for the east- and westward crossings. The results are therefore uniform and consistent.
The example of routes to Vyborg and Saint Petersburg demonstrate that it is
probably impossible to find an optimum solution that would fit for all harbours,
ships, and constraints. The performance analysis shows that a northward shift of the
Vyborg route (passing by Gogland in the north) would improve travel time and fuel
consumption measurably. On the other hand, such a shift would separate the Vyborg
route from the Saint Petersburg route and would generate a decomposed system of
fairways. Optimization is configuration dependent and pursues individual solutions
for small or single-member networks with higher efficiency. This becomes apparent
for harbours like Sillamäe and Ust-Luga. The established network with its tree-like
structure, from which the different routes branch off, forces the maritime traffic to
take uneconomical detours with up to 25 nm longer fairways, which amount to about
15 % of the length.
The port of Ust-Luga is situated in Luga Bay in the south-eastern part of the
gulf. Although most of the fairway designs choose for economical reasons a more
or less direct route out of the bay and towards the west, the route atlas orders vessels
to take a detour to the north, to meet the Saint Petersburg fairway. This amounts
to about 2 hours additional travel time, and more than 1 metric ton (mt) more fuel
consumption, which is significant for the relatively small distances along the Gulf of
Finland. The existing fairway, as specified by the route atlas, is about 25 nm longer
than any other fairway. As this fairway is situated in the southern part of the gulf, its
performance is not much affected by the River Neva outflow. The path length and
integrated effects of the shallow water resistance are again the main performance
limiting factors.
It is not surprising that near coastal fairways, which are most favoured by SA
designs, are strongly affected by shallow water hull resistance. Other fairways show
quite small performance variations. The best solution is provided by the SeaPlanner optimization routines, which feature short distances and courses that directly
target the Baltic Proper. The optimized Ust-Luga fairways are mainly defined by
geography and are identical for eastward and westward crossings.
The port of Sillamäe is situated in north-eastern Estonia. Its connection to the
Baltic Sea fairway network also runs along the Saint Petersburg line, which meets
the Sillamäe fairway near Gogland. The existing RA route is on average about 11 nm
longer than the alternative designs, which amounts to up to 1 hour longer travel time