I wrote here about Watson’s Double Canal Boat, saying inter alia that, in 1839, William Watson, manager of the inland department of the City of Dublin Steam Packet Company, patented:
an improvement in the construction of ships, and which improvement is also applicable to all kinds of sea-going vessels; and also certain improvements in the construction of boats and other vessels intended to be used on canals and inland navigations. [1]
I quoted the Mechanics’ Magazine of December 1839, which said that:
Three canal barges have already been built upon Mr Watson’s plan of construction, of 60 tons burthen each, and with eminent success.[2]
I said that the size suggested that these canal barges were for the CoDSPCo’s Irish inland operations, but that I had no information about where they were built. I have now found information about one builder.
SHIP BUILDING
On Thursday, the 22nd instant, a fine new trade boat, built with iron ribs, according to the patent of William Watson, Esq., and belonging to the City of Dublin Steam company, also a new smack, 50 tons measurement, were launched from the Brunswick dock-yard, Ringsend Docks.[3]
I would be grateful for more information.
[1] “List of patents granted for Scotland from 18th March to 18th June 1839” in The Edinburgh New Philosophical Journal , exhibiting a view of the progressive discoveries and improvements in the sciences and the arts Vol XXVII No LIII — July 1839; “List of English patents granted between the 25th of May and the 25th of June, 1839” in The Mechanics’ Magazine No 829, Saturday, June 29, 1839
[2] The Mechanics’ Magazine Vol XXXII No 855 28 December 1839
[3] The Freeman’s Journal Saturday 24 July 1841. An almost identical note appeared in the Dublin Evening Mail of Monday 26 July 1841.
Irish waterways history 
Pingback: Grace’s Guide and the Brunswick Dockyard | Irish waterways history