Hat-tip to Carthach Ó Maonaigh for pointing me to this article about a [proposed?] canal I had not heard of before: Richard Talbot’s Canal in Malahide. Talbot intended to build a canal to carry heavy goods inland from Malahide harbour via Swords to join the Broadmeadow River at Fieldstown.
This is yet another example of [proposed] eighteenth century investment and improvement by estate owners. Most of the canals I’ve covered were inland, and often associated with bogs for reclamation and turf extraction; this one shows that improvers could have other aims in mind.
Incidentally, the articles on the Old Yellow Walls site seem to be carefully researched and referenced.
Irish waterways history 