The study uses seven scenarios to present the locations of current and potential future rescue tugs. Each of the scenarios was conducted through a model to estimate the possibility that a rescue tug would arrive in time to help a disabled vessel. The model considers the coastline and historical wind conditions in the area and the time needed for a tug to reach the disabled vessel, which was calculated based on the tug’s starting location, mobilization time, travel speed, route, and time to establish a tow line. The disabled vessel’s drifting time before grounding was calculated based on drift characteristics of particular vessel sizes and types that commonly transit the area, along with wind conditions drawn from historical wind data.
All scenario results show a higher possibility of rescue for vessels that begin their drift farther offshore. The time it takes for an ETV to reach a disabled vessel is influenced by start location, mobilization time, and transit speed.
Moreover, passenger vessel routes most often overlap with the lowest probability of rescue zones, partly because these vessels often travel closest to the coast. Tanker routes, with the exception of Juan de Fuca Strait, fall outside the 99% probability of rescue zone for all scenarios, mostly because of the voluntary Tanker Exclusion Zone already in place. Cargo and fishing vessel routes cross a range of zones, but primarily transit the 50-90% and 90-95% zones along Canada’s Pacific coast. These results are preliminary, based on a relatively small vessel transit data set, and will be revisited with a larger dataset in a subsequent report.
The aim of this is to increase decision-makers’ understanding of the role that ship routing and capable, strategically-located, and promptly-deployed rescue tugs can play in reducing risks associated with shipping traffic in western Canadian waters. The results can be used to risk mitigation decisions, such as the best location for rescue tugs or other proactive vessel management measures to reduce the risks associated with drifting vessels along Canada’s Pacific coast.
You can see more information in the PDF herebelow