It has cost the Suez Canal Authority $US14-15 million ($18.3-19.6 million) each day the 400-metre long Ever Given ship remains lodged. 

The vital passage is used to carry cargo between Asia and Europe, valued at more than $US9 billion a day.

Dredgers working to dislodge the stranded vessel have so far shifted 27,000 cubic metres of sand, to a depth of 18 metres, and efforts would continue around the clock dependant on wind conditions and tides, the Suez Canal Authority (SCA) said in a statement.

A ballast tank at the bow of the ship has also been damaged, and the vessel will have to be inspected once it is freed, two people familiar with the salvage operation said.

Egypt's President Abdel Fattah al-Sisi has ordered preparations for the possible removal of some of the ship's 18,300 containers, SCA Chairman Osama Rabie told Egypt's Extra News.

Any operation to lighten the ship's load will not start before Monday, an SCA source said.

At least 369 boats are waiting to transit the canal, Mr Rabie said, including dozens of container ships, bulk carriers, oil tankers and liquefied natural gas (LNG) or liquefied petroleum gas (LPG) vessels.

Dozens of others still listed their destination as the canal, though shippers increasingly appear to be avoiding the passage. 

Mr Rabie said ships affected by the blockage may be offered discounts and that he believed investigations would show the canal was not responsible for the Ever Given running aground.

Rescue workers from the SCA and a team from Dutch firm Smit Salvage have been weighing whether some cargo will need to be removed by crane in order to refloat the Ever Given, one of the world's biggest container ships.

Experts have warned that such a process could be complex and lengthy.

Mr Rabie said he hoped it would not be necessary, but that Egypt would take up offers of international assistance if it did switch to that strategy.

Rudder moving, propeller now working

About 15%of world shipping traffic transits the Suez Canal, which is a key source of foreign currency revenues for Egypt.

High winds are believed to have caused the Ever Given to become stuck diagonally across a southern section of one of the world's busiest waterways.

"There are positive indicators from yesterday and the day before yesterday," Mr Rabie told Egyptian state TV.

"The rudder was not moving and it is now moving, the propeller is working now, there was no water underneath the bow, and now there is water under it, and yesterday there was a 4-metre deviation in the bow and the stern."

However, two SCA sources told Reuters that a mass of rock had been found at the bow of the ship, complicating salvage efforts.

"We're dividing the day into two halves, 12 hours for dredgers and 12 hours for tugs because not all times are suitable for tugs due to the tide," Mr Rabie said, adding that 14 tug boats were being deployed.

From the dredging done so far it was still unclear whether the ship was stuck on soft sand, compact sand or clay, which will determine how easily it may shift free, said one official involved in the salvage operation.

Shipping rates for oil product tankers nearly doubled after the ship became stranded, and the blockage has disrupted global supply chains, threatening costly delays for companies.

If the blockage drags on, ships may decide to reroute their cargoes around the Cape of Good Hope, adding about two weeks to journeys and extra fuel costs.

Source | Reuters/AP