Clearer details are emerging of the impact on supply chains of the attacks on containerships in the Red Sea that led carriers to re-route services.

Widely rumoured figures of a million teu being stuck on ships close to the Bab-el-Mandeb Strait, off the coast of Yemen, have been discredited by Xeneta, with chief analyst Peter Sand telling The Loadstar the true impact was about quarter of that.

He added: “Excluding ships currently transiting the Suez Canal, or waiting to do so, the impact is sizeable, but it is not mind-blowing.”

Mr Sand said the figure was 237,971 teu, with Xeneta and Marine Benchmark data listing the affected vessels, which include the MSC Gulsun (23,756 teu), ONE Triumph (20,170), MSC Oliver (19,224), Cosco Andes (14,500) and Maersk’s 8,850-teu Londrina.

But he added: “It is important to note that those are the nominal capacities of the vessels, not the volumes they are carrying.

“Also, of the ships ‘stuck’ in the Red Sea, some are there deliberately as they are calling at Jeddah, but quite a few were also on the way back to the Far East when the situation escalated and are now in various holding positions.”

News began filtering out early in the week of major container operators pausing all routings through the Red Sea in the wake of the attacks by Iranian-backed militias.

Analysts, including Mr Sand and Vespucci Maritime CEO Lars Jensen, said shippers could expect two-week delays to their goods arriving.

Portcast data shows rerouting via Africa would add seven days to South Asia-US sailings and 10 days to Asia-Europe sailings going via the Cape of Good Hope, and estimates suggest the extra transit and fuel costs will be north of $2m per vessel.

Despite the much lower tonnage being impacted than first thought, Mr Sand said it was clear the impact would still be sizeable.

“This is backed up by what many shippers and major retailers are saying – that they expect to see some of their products being unavailable in a few weeks as a result of these delays, and insufficient stocks to cover any shortfall,” he said.

“I think there are two other key points. Firstly, the issue is not going away any time soon. A taskforce has been set up to try and impede attacks, but it needs to find its way to work.

“And, unlike in the case of attacks by pirates, where a warship can fend them off, this is something different.”

He said the different proposition presented by these militias meant the taskforce would require time to determine the best means of defending the merchant ships.

Added to this, he said, increased front-loading brought about by the attacks would coincide with the Chinese New Year holiday in February to, likely, engender much higher spot rates.

And that, he added, could “also affect contract rates”.