I have often lamented the poor classification methods used by those who look after collections of paintings. They focus on the name of the painter, the date and the school to which he or she belonged, rather than on the really important facts: whether or not a painting shows a steamer, barge, canal or other object of industrial heritage interest. Thus, as I pointed out here, you get titles like “View looking down on a jetty and boats on a lake with a church in the distance” that ignore the most important aspect: that the pic shows a steamer on Lough Erne.
The other problem is that the paintings are in galleries scattered hither and yon, which means that a serious search for steamers, barges and canals would require hours of driving followed by hours of rummaging through archives, even though each pic would require only a few seconds’ attention to determine whether or not it is worthy of notice. The cost-benefit ratio is all wrong, but the use of technology can solve the problem.
I was delighted therefore to learn that, in HM Realm, the BBC and the Public Catalogue Foundation have put online tagged images of [almost] all the 200,000+ oil paintings in public ownership in the UK at the Your Paintings site. The collection is searchable: the search will return artists, painting titles and tags. And you can help by adding tags, if you have more information about a painting.
There is not much of Irish waterways interest, which is scarcely surprising, but there is an interesting illustration of the use of a pole on the Lagan [I’d welcome comment on what’s happening in that pic] and the barge at Edenderry. There is also some material for steam men.
It would be nice if Irish galleries would now do the same. The cost could be met by selling off the originals, which would no longer be necessary, and closing the galleries, at a saving to the public purse.
Irish waterways history 
It would seem likely that, given the man with the pole in the picture is on the bow, he’s run up the bank and is now trying to free himself. Absence of a horse is interesting as there is clearly a towpath one side of the navigation. Plenty of flow in the fore ground, but it is a painting, not a photograph – artistic license and all that.
Picture of barge in Edenderry is also interesting – it has a wheel rather than a tiller. I’m not familiar with that set up on Irish canal barges. Again, quite possibly artistic license?
The Lagan is a river navigation with some cuts [two sections I’ve seen here and here] and a flow would not be surprising, but the absence of a horse is odd, although the navigation did not have a horse towing path along its full length when first built. But look at this one. May Blair says:
Clicking on the name of the artist, Hugh Frazer (1795–1865), produces a slide show of 26 pics, most of them of the Lagan or Belfast.
Incidentally, there are three more pics of the Lagan, showing Newforge. Searching by name of river or town produces some more material of interest. Here’s a nice one of the sixth lock at Drum, which complements my page (link above). Note the colours used on the lock gate; I don’t know whether it was a particularly unionist lock or whether all Lagan lock gates were painted the same way. We are indebted to Max hastings’s grandfather for the information that locks on the Ulster Canal had “red handles“; I don’t know whether he meant the beams of the gates or something else.
May Blair has a photo of the motor-boat Nellie of Hilden; it has a wheel, as do the motor-lighter [I use her terms] Ruby and the Ida. However, the unpowered lighter Nellie (which she emphasises was not the same boat) had a tiller.