20.4 Collision and Allision Risk Modelling
- The collision and allision risk modelling has been presented and discussed in section 14.
- Six scenarios were assessed:
- Pre wind farm with the base case vessel traffic level.
- Pre wind farm with a future case vessel traffic level defined by:
- A 10% increase in traffic; and
- A 20% increase in traffic.
- Post wind farm with the base case traffic level.
- Post wind farm with a future case vessel traffic level defined by:
- A 10% increase in traffic; and
- A 20% increase in traffic.
- Table 20.1 presents a summary of the collision and allision modelling results.
Table 20.1: Risk Results Summary
Risk | Scenario | Annual Frequency | ||
|---|---|---|---|---|
Pre Wind Farm | Post Wind Farm | Increase | ||
Vessel to vessel collision | Base case | 4.14×10-4 (1 in 2,418 years) | 5.42×10-4 (1 in 1,845 years) | 1.28×10-4 |
Future case (10%) | 5.45×10-4 (1 in 1,835 years) | 7.28×10-4 (1 in 1,374 years) | 1.83×10-4 | |
Future case (20%) | 6.33×10-4 (1 in 1,580 years) | 8.41×10-4 (1 in 1,188 years) | 2.09×10-4 | |
Powered vessel to structure allision | Base case | - | 6.91×10-3 (1 in 145 years) | - |
Future case (10%) | - | 7.60×10-3 (1 in 132 years) | - | |
Future case (20%) | - | 8.29×10-3 (1 in 121 years) | - | |
Drifting vessel to structure allision | Base case | - | 2.16×10-4 (1 in 4,619 years) | - |
Future case (10%) | - | 2.38×10-4 (1 in 4,199 years) | - | |
Future case (20%) | - | 2.60×10-4 (1 in 3,849 years) | - | |
Fishing vessel to structure allision | Base case | - | 4.08×10-2 (1 in 24 years) | - |
Future case (10%) | - | 4.49×10-2 (1 in 22 years) | - | |
Future case (20%) | - | 4.90×10-2 (1 in 20 years) | - | |
Total | Base case | 4.14×10-4 (1 in 2,418 years) | 4.85×10-2 (1 in 21 years) | 4.81×10-2 |
Future case (10%) | 5.45×10-4 (1 in 1,835 years) | 5.35×10-2 (1 in 19 years) | 5.30×10-2 | |
Future case (20%) | 6.33×10-4 (1 in 1,580 years) | 5.84×10-2 (1 in 17 years) | 5.78×10-2 | |