The Suez Canal was one of the most significant engineering projects of the 19th Century. It was a gargantuan task that took nearly 20 years to build and an estimated 1.5 million workers took part – with many thousands dying in the process. But when it finally opened in 1869, ships could travel from the Red Sea – between Africa and Asia – to the Mediterranean, cutting weeks off a journey. It was a revolution for trade.

Ever since, passage through the canal has been considered more or less vital to global business. Shipping firms pay what amounts to several billion dollars every year to the Suez Canal Authority, an Egyptian state-owned entity, for the privilege of travelling via the canal.

To take an example, it cuts a modern journey from Singapore to Rotterdam in the Netherlands by nearly 3,500 nautical miles (6,480km) – saving vessel owners lots of time and lots of money.