(Bloomberg) — Supply Lines is a daily newsletter that tracks trade and supply chains disrupted by the pandemic. Sign up here.The company battling to dislodge a ship that’s blocking the Suez Canal said a crane will arrive at the location this weekend to begin the painstaking process of removing some of the vessel’s cargo in a bid to help it refloat.The Ever Given, a 400-meter long container ship with almost $1 billion of cargo on board, jammed itself fast into the banks of the waterway on Tuesday, and estimates for it to be freed have now risen to over a week. Tug boats and dredgers have made a little progress, but the urgent need to restart the canal means thousands of the carrier’s steel boxes need removing as soon as possible so that the carrier sits higher in the water.“We are awaiting the arrival of a crane with which we can lift containers from the ship,” Peter Berdowski, chief executive officer of Boskalis Westminster, the parent company of the salvage team SMIT, said on Dutch television on Friday. “We will start taking containers from the ship anyway this weekend.”The pressure is on to get the ship floated and out of the way as soon as possible. The blockage is holding up something like 10% of global trade and a swath of imports that are critical to Europe’s supply chains and industry. Scores of ships have already decided to go the long way around — passing the southern tip of Africa — also depriving Egypt of vital revenue.PrecedentThere is precedent for a lightering operation. Back in November 2004, another vessel, this time a Suezmax-class oil tanker named Tropic Brilliance, ran aground after mechanical problems in the canal, wedging itself across the conduit in a similar way to the Ever Given. Canal authorities were forced to close the canal. In an almost carbon copy of events over the past three days, tugboats tried to use their immense pulling power to free the tanker, which was carrying 85,000 tons of fuel oil, but those efforts failed.Ultimately, salvage experts brought another tanker alongside, the El Nabila, and transferred roughly 22,000 tons of cargo. On the third day of the grounding, and lighter after the transfer, tugboats were able to free the Tropic Brilliance and reopen the canal. The grounding triggered what, until then, was one of the longest closures of the waterway in years.But lightering the Ever Given will be a different matter. The boxship can carry 20,000 twenty-foot equivalent containers. If salvage experts need to move the same proportion of cargo as they did to free the Tropic Brilliance, it would entail physically removing, one by one, about a quarter of the boxes, an operation that will take days.Helicopter OptionAnother option mooted for this lightering process was to deploy powerful helicopters that could take off the boxes — each one potentially holding up to 22 tons of cargo. They would be hugely expensive, costing an upfront fee and an hourly rate that can get up to $20,000, according to Farrell.Air lifting could only be performed by a special type of aircraft called sky-crane helicopters that are able to haul loads of 25,000 pounds (about 12.5 tons), according to Nick Sloane, the salvage master responsible for re-floating the Costa Concordia, which capsized off Italy in 2012.“It is concerning that they haven’t gotten her out yet,” said Alan Murphy, CEO of Sea-Intelligence. “If there’s news that the hull has been breached, or they need to evacuate the boxes to get her free, then it’s a big-time problem.”For more articles like this, please visit us at bloomberg.comSubscribe now to stay ahead with the most trusted business news source.©2021 Bloomberg L.P.