Incident (grounding/sinking) of a vessel blocking a major port 

Impact 5
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risk indicator
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Impact & Likelihood
Impact key
5 Catastrophic
4 Significant
3 Moderate
2 Limited
1 Minor
Likelihood key
5 >25%
4 5-25%
3 1-5%
2 0.2-1%
1 <0.2%


There is a risk that an accident involving a vessel could block a major UK port. The consequences of this risk were observed in the Suez Canal in 2021, which was blocked by one of the largest container ships in the world as a result of it running aground. This resulted in delays to hundreds of vessels waiting to transit through the canal and had significant impacts on trade. The UK has plans and procedures, maintained and executed through the Secretary of State’s Representative (SOSREP), to deal with major salvage incidents. The SOSREP will oversee the recovery operations developed by vessel owners and any appointed salvors. Where a counter pollution response component exists within these plans, the Maritime and Coastguard Agency’s Counter Pollution and Salvage team will ensure that arrangements are in place to quickly respond, limit and reduce impacts on the environment, marine habitats and local coastal communities.


The reasonable worst-case scenario is based on a vessel grounding or sinking, which results in the blockade of a major container port. The port would be unable to commercially operate in any significant capacity for a number of months. Cargo would no longer be able to transit through the port to enter into the UK, potentially impacting critical supply chains. Ships would need to be rerouted, which would be challenging due to their size and the infrastructure required to accommodate them and their critical goods. As a result of the grounded or sunk vessel, boat crew and/ or passengers would need to be provided with shelter and treatment for any injuries sustained. There may also be a possible environmental impact from the incident where pollutants are spilt into the sea.

Key assumptions

The incident would be the result of extreme weather, or human or technological failure. The port would be able to resume limited activity in the short term by dredging or removal of the wreck.


A vessel grounding is more likely than a vessel sinking. Grounding is easier to resolve through refloating rather than the salvage of a wreck. The business operation of the port would be expected to continue at a reduced capacity. Where critical cargo such as ultra-cold supply chains (for example some vaccines) are impacted due to specialist infrastructure required at ports, vital goods may be lost by not being able to store them correctly.

Response capability requirements

Generic emergency response capabilities such as search and rescue and policing would be required, alongside specialist environmental support and support for victims of the accident. Salvage capability and expertise would need to be imported, which could take months. Dredging can be time consuming and bureaucratic; the government may need to intervene to accelerate the process. If an uninsured vessel is involved, the government may need to provide financial assistance. Direction from the government will be vital in ensuring critical goods are given appropriate priority to meet national needs.


Recovery length would depend on the nature of the incident, the location, accessibility to the wreck and availability of specialists to conduct the wreck removal. Partial recovery would be possible by dredging another channel where possible. Insurance would likely protect the facility from financial hardship during this time, but returning to business would be the port’s priority.