Looking at the challenges of elevation on canals and the different innovative approaches that have been taken to address this.
"In the mid-18th century, James Brindley changed the world of canal construction forever, armed with a large round of Cheshire cheese. Faced with the challenge of crossing the River Irwell in Lancashire, he knew he had to convince Parliament that his new structure was the way forward. Apparently, Brindley demonstrated the unconventional idea of carrying one body of water above another by dividing the cheese into two equal halves, to represent the semicircular arches, and then laying a rectangular object over the top to show how the the river would flow below the aqueduct and the canal would flow above (as told in Memoir of James Brindley, John Weale, 1844). Although dismissed by many for his proposed ‘castle in the sky’, Brindley won them around and the Barton Aqueduct (opened 17 July 1761) went on to become the first navigable aqueduct in the country, and remained a pioneering structure until the use of cast iron allowed more ambitious projects to be built. In 1805, Thomas Telford completed the 307-metre Pontcysyllte Aqueduct on the Llangollen Canal, which is today the longest navigable aqueduct in the UK. At 38 metres, it’s also the highest in the world. The construction of the ‘Ponty’ included some unorthodox methods: oxblood was mixed into the mortar (it was believed to strengthen a building) and supposedly the cast iron joints were caulked with flannel dipped in boiling sugar, before being sealed with lead."
Excerpt from Waterfront, August 2017, Words only.