Risk Analysis of Sea Traffic in the Area around Bornholm, 2008. - VTT

Risk Analysis for Sea Traffic in the Area around Bornholm
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In the process of the study, two workshops were held, the first in order to indentify
the relevant hazards, the second in order to validate and discuss the results.
The conclusions of the second workshop served as feedback in order to
refine the risk model.
Results: Bornholmsgat
The introduction of the traffic separation scheme in the Bornholmsgat has had a
clear effect upon navigational risk. When comparing the situation in 2005 and
that in 2006, it appears that expected accident costs fell from DKK 29.0 million
(€3.9 million) to DKK 18.3 million (€2.5 million) per year. This corresponds to
a decrease by DKK 10.7 million per year or 37 percent.
The largest part of this effect is due to a strong reduction in head-on collision
risk. This is an obvious effect of the traffic separation which provides one sailing
lane for each traffic direction. Besides, crossing collisions were reduced,
although it can be expected that the actual reduction is even greater. The new
traffic separation scheme forces traffic from Øresund and from Kadetrenden to
merge in a designated cautionary area, which makes other ships’ behaviour
more predictable. However, this effect is not included in the physically-based
collision model. Groundings are equally reduced, but their contribution to total
risk is limited due to their comparatively small consequences.
Accident costs are dominated by clean-up costs due to oil spillage. This dominance
is clear in the Bornholmsgat itself, where oil tankers are a significant
traffic contribution, while being weak in the remaining waters surrounding
Bornholm.
As a result, it can be said that the introduction of the traffic separation scheme
has reduced navigational risk significantly.
Results: Gdańsk
Bay traffic
As mentioned, it was conceived to divert vessels sailing to and from Gdańsk,
Kaliningrad and Klaipėda to different routes, in dependence of their respective
draught. The corresponding traffic volume is low compared to that in the Bornholmsgat,
which means that the absolute accident risk reduction is relatively
low, too. Accident costs can be expected to drop from DKK 2.34 million to
DKK 2.19 million per year, in the areas north-east and south of Bornholm,
where the traffic diversion would be implemented. This corresponds to a drop
by 6 percent.
When including the heavily frequented, but only marginally affected Bornholmsgat
in the consideration, total expected accident costs fall from currently
DKK 18.3 million (€2.47 million) to DKK 18.0 million (€2.42 million) per
year. This decrease by DKK 285,000 (€38,000) per year corresponds to a reduction
by 2%.
However, these numbers reflect only the accident costs, while ignoring direct
costs, i.e. ship operation costs and externalities. They, too, are influenced because
ships would on average be forced to take slightly longer routes than presently.
These costs would rise by DKK 4.00 million (€537.000) per year, which
clearly outbalances the reduction in accident costs. Out of these 4 millions,
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