By contrast, the Titanic, built by White Star Line nearly a century ago and at the time the largest steam ship ever, measured 269 metres and was less than a fifth of the size of today's behemoths.

This desire for improvement was “the greater journey” of Mr McCullough's title, following the often dangerous journey across the Atlantic, first by sailing ship and only later under steam.

After about 30 minutes the ship is ready to steam into the wider waters of the canal.