Our Heritage Manager, Nigel Crowe, talks about how canals were built by moving earth efficiently.
Constructing canals was all about moving earth as efficiently as possible. Earth removed from the channel was used to raise the towpath, while that cut from the lower end of a lock approach was transferred to its top end. Ideally, a cutting had an embankment at one or both ends, formed from its excavated material.
Early canals were generally low-level constructions and followed the winding contours of the land. Later canals were more daring and examples like the Grand Union, Shropshire Union, Tame Valley and Birmingham New Main Line have impressive cuttings and embankments.
Thomas Telford was the great earth-mover, his Smethwick Cutting, completed in 1829 is 22 metres deep in places. His masterpiece was the Shropshire Union Canal, which features a stupendous deep cutting at Tyrley, famed for its steep sides and crossed by high level bridges. The canal has huge embankments too, like those at Shebdon and Shelmore, with tunnels carrying roads through them.
The great earthworks of the Canal Age were constructed by sheer manpower and the use of barrow runs, trams and temporary iron railways. But geotechnical engineering was still in its infancy and problems encountered during construction (soil slippage, water seepage) persist in some places to this day. Burrowing animals were also a concern; in the 1820s the Glamorganshire Canal Company employed a full-time Molecatcher. Today, we inspect and monitor earthworks on a regular basis, but we rarely need to chase moles away.
The work carried out by the heritage team is extremely varied, covering all sorts of structures and a wide variety of projects. Not one week is the same and we keep learning all the time, meeting some fascinating people and visiting stunning places along the way. We are hoping that through our blogs we can share some of our passion for the amazing industrial heritage of the inland waterways.See more blogs from this author