Strong winds may not be enough to explain the grounding of a ultra large containership in the Suez Canal.
Experts have indicated a hydrodynamic phenomenon known as the bank effect may have played a role in the grounding of the 20,288-teu Ever Given (built 2018).
The weather at the time, which included strong gusts, have been cited as the key factor behind the grounding of the Shoei Kisen-owned boxship.
Data compiled by marine insurance intelligence company Concirrus indicates average winds speed of between 22 knots and 23 knots, with gusts of between 45 knots and 47 knots, at the time of the grounding on 23 March.
But Concirrus data analysts James Whitlam suggests the winds alone might not be enough to explain the grounding, unless the gusts became prolonged.
“The average wind speeds at the time are well within normal operating conditions. If there was a sustained gust, sustained being the important word, then this could potentially start to impact a vessel of this size and windage [air resistance],” he said.
The other factor which experts say could have played a role is a bank effect.
Whitlam said this occurs when a vessel travels down an enclosed waterway and the pressure waves from the hull interact with the bank to cause pressure differentials.
“This can result in the stern of the vessel to swing towards the bank therefore causing deviation from the intended course. Vessel speed is a notable component of the magnitude of this effect,” Whitlam explained.
The ship was sailing at 13.7 knots when it went aground according to AIS data.
If bank effect played a part, experts further said that it might be more accurate to describe the incident as a collision with the Suez Canal wall rather than a grounding.
An analysis in the Financial Times, which examined the bank effect theory, described the incident as a “walling”.
The Ever Given was transiting northbound through the canal en route to Rotterdam with two canal pilots on board at the time of the accident.
The cause of the incident will play a major factor in deciding liability.
There is an investigation being carried out by shipowner Shoei Kisen and its insurers and the Panama flag state under which the Ever Given is registered.
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