LONDON — Shipping experts believe it could take days or even weeks to free the 224,000-ton vessel that is wedged across the Suez Canal, blocking one of the world"s busiest waterways since Tuesday. The Ever Given, a container ship almost as long as the Empire State Building is tall, ran aground on March 23 after being caught in 40-knot winds and a sandstorm that caused low visibility and poor navigation, the Suez Canal Authority (SCA) said in a statement. Authorities attempted to re-float the vessel Thursday morning but were not successful. Another attempt will be made later on Thursday, according to Bernhard Schulte Shipmanagement, the vessel"s technical manager. Meanwhile, at least 160 ships carrying vital fuel and cargo are waiting to pass through the blocked waterway, according to a senior canal pilot at the SCA. Dislodging the vessel could take "days to weeks, depending on what you come across," according to Peter Berdowski the CEO of Boskalis, whose sister company SMIT salvage is now working to free the ship. Berdowski told Dutch TV on Wednesday that his company had determined it was impossible to free the ship with its current cargo on board. "The ship with the weight that it [has] now has is impossible to pull," he said. "You can forget about that." Meanwhile, at least 160 ships carrying vital fuel and cargo are waiting to pass through the blocked waterway, according to a senior canal pilot at the SCA. Dislodging the vessel could take "days to weeks, depending on what you come across," according to Peter Berdowski the CEO of Boskalis, whose sister company SMIT salvage is now working to free the ship. Berdowski told Dutch TV on Wednesday that his company had determined it was impossible to free the ship with its current cargo on board. "The ship with the weight that it [has] now has is impossible to pull," he said. "You can forget about that."