A great day for fans of ship canals

Today, 25 April (2009), is a great day for anyone mad about ship canals. It was on this day 50 years ago that the first ships passed through the St Lawrence Seaway and on this day 150 years ago that work began on the Suez Canal.

Few people seem to be aware that the Suez Canal was not the first navigable route from the Mediterranean to the Red Sea. As long ago as the second millennium BC, boats sailed up the Nile from the Med and then followed a small canal from a branch of the river into the Red Sea, which at the time reached as far north as the Great Bitter Lakes.

The canal may have been dug as early as the time of the pharaoh Senusret III in the 19th century BC but it was certainly in place by the time of Rameses II in the 13th century BC.

The waterway fell into disrepair but, according to the Greek historian Herodotus, the pharaoh Necho II (reigned 610–595BC) ordered its re-excavation. After Necho’s death the project was abandoned when an oracle warned that barbarians — ie, the Persians — would benefit from its completion.

In the event, it was indeed the Persians, under Darius I, who completed the project after Persia’s conquest of Egypt in 525BC. Herodotus records that Darius’s canal was wide enough for two triremes to pass with oars extended — and a trireme was a large vessel with a crew of some 200.

The canal again fell into disuse but was reopened by Ptolemy II in 270–269BC. Over the centuries, its maintenance became increasingly difficult as the Red Sea receded and the Nile silted up.

By the time of Cleopatra (69–30BC) it had ceased to be navigable. But over the following centuries it was rebuilt, destroyed and rebuilt again until finally abandoned in about AD750. Or maybe not, because there is some evidence that it was briefly repaired again in about AD1000.

At the end of the 18th century, Napoleon Bonaparte developed an interest in constructing a Med–Red link.  But he abandoned his project after a survey wrongly concluded that the Red Sea was 10m higher than the Med, which would have involved the expensive construction of locks.

In contrast, the need for locks did not deter the constructors of the St Lawrence Seaway, which has a total of 19 huge locks.