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

More documents

Recommendations

Info

Risk Analysis for Sea Traffic in the Area around Bornholm 28 However, direct costs are not relevant for the retrospective view upon the introduction of the traffic separation scheme in 2006. When accident costs are the only cost/benefit contribution, it becomes meaningless to differentiate between a comparative risk assessment (using monetary units) and a cost-benefit assessment. Results for 2005 traffic data 5.3.1 Effect upon expected accident frequency Table 5 provides a concentrated overview over the results obtained for the traffic pattern observed in 2005. A more visual illustration is given in Figure 14 and the following 2 . Table 5 Accident frequencies expected for 2005 traffic data Area Parallel collisions Crossing collisions Imprecision groundings Missed-turn groundings Total Bornholmsgat 0.135 0.200 0.190 0.000 0.525 NE of Bornholm 0.001 0.010 0.087 0.000 0.098 S of Bornholm 0.006 0.033 0.192 0.000 0.232 All 0.142 0.243 0.469 0.000 0.855 Little surprisingly, the largest share of all accidents is expected in the Bornholmsgat, where sea traffic is heaviest. The contribution of parallel collisions, crossing collisions and groundings due to imprecise navigation is in about balanced there. Parallel collisions are made up of head-on collisions and overtaking collisions in equal shares (Figure 14). This is not the case for the areas north-east and south of Bornholm. There, parallel collisions < crossing collisions < imprecision groundings is the case, each time with about one order of magnitude in between. Figure 14 and the following illustrate that traffic in this area is not only weaker, but also much less concentrated when comparing with the Bornholmsgat. Parallel collisions are much more likely if traffic for concentrated traffic. With crossing collisions, there is no such dependency (see also Appendix A for an explanation of the collision models). Grounding is by far the most significant contribution to accident frequency in these waters. Missed-turn groundings do not appear at all in any of the simulations. This is due to the model that was chosen, which is the only scientifically approved model available at the moment. However, it is designed for much narrower straits and therefore does not describe the present situation sufficiently well (discussion in Appendix B). In fact, a number of this type of accident have been observed in the Bornholmsgat. 2 Note that the figures also include results lying outside the geographical limits of the study area, unlike the information in the tables (see Figure 2 for description of the study area). P:\65775A\3_Pdoc\DOC\P-65775A main report final corr prepared for PDF.DOC .
Risk Analysis for Sea Traffic in the Area around Bornholm 29 Collisions involving small vessels amount to 5.8% of accidents. The majority of these accidents concern fishing boats (5.6%), whereas only a small part involves sailing and motor yachts (0.2%). Results for 2006 traffic data Table 6 contains the basic accident frequencies for the traffic pattern recorded in 2006. These numbers are illustrated by Figure 15 and the following. Table 6 Accident frequencies expected for 2006 traffic data Area Parallel collisions Crossing collisions Imprecision groundings Missed-turn groundings Total Bornholmsgat 0.120 0.204 0.169 0.000 0.493 NE of Bornholm 0.001 0.009 0.088 0.000 0.098 S of Bornholm 0.009 0.035 0.195 0.000 0.239 All 0.130 0.248 0.452 0.000 0.830 Judging by Table 6, the relative contribution of the different areas and accident types is in about the same as for 2005. Amongst others, this is also the case for parallel collisions. Yet, Figure 15 reveals that parallel collisions are dominated by overtaking collisions, whereas head-on collisions contribute only a small percentage. Small vessels contribute in a similar way as in 2005: A share of 4.9% of all accidents is due to collisions with fishing boats, 0.2% are due collisions with yachts. Comparison of 2005 and 2006 Judging by the overview in Table 7, the total accident frequency estimate changes only little between 2005 and 2006 traffic data. A reduction by 3% is not strong enough to be called significant. The result depends upon each single ship passage and it has to be considered that no ship sails precisely the same way twice. Traffic volume was practically the same in the two years. Table 7 Change in expected accident frequencies from 2005 to 2006 Area Parallel collisions Crossing collisions Imprecision groundings Missed-turn groundings Total Bornholmsgat -11% 2% -11% - -6% NE of Bornholm -39% -2% +1% - +0% S of Bornholm +47% +5% +1% - +3% All -9% 2% -4% - -3% However, there are significant differences with respect to the share of the different accident types, which is more than relevant, considering that different accident types have different consequences (which will prove to have a great effect in section 5.3.2). P:\65775A\3_Pdoc\DOC\P-65775A main report final corr prepared for PDF.DOC .
Page 1 and 2: Søfartsstyrelsen Risk Analysis of
Page 4 and 5: Risk Analysis for Sea Traffic in th
Page 80 and 81:
Risk Analysis for Sea Traffic in th
Page 82 and 83:
Page 84 and 85:
Page 86 and 87:
Page 88 and 89:
Page 90 and 91:
Page 92 and 93:
Page 94 and 95:
Page 96 and 97:
Page 98 and 99:
Page 100 and 101:
Page 102 and 103:
Page 104 and 105:
Page 106 and 107:
Page 108 and 109:
Page 110 and 111:
Page 112 and 113:
Page 114 and 115:
Page 116 and 117:
Sejladssikkerheden omkring Bornholm
Page 118 and 119:
Page 120 and 121:
Page 122 and 123:
Page 124 and 125:
Page 126 and 127:
Page 128 and 129:
Page 130 and 131:
Page 132 and 133:
Page 134 and 135:
Page 136 and 137:
Page 138 and 139:
Page 140 and 141:
Page 142 and 143:
Page 144 and 145:
Page 146 and 147:
Page 148 and 149:
Page 150:
show all

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

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?