Last month I wrote about the lock at Newcomen Bridge on the Royal Canal:
Industrial Heritage Ireland has created a page giving the history of the railway crossing at Newcomen Bridge. However, it would be nice to have some documentary evidence about the resiting of the lock — and about the headroom under the bridge before the lock was moved.
Here it is, from the Freeman’s Journal of 12 April 1873, in an article about the new Spencer Docks:
Above the new metal bridge there is a basin for Canal boats, with a quayage of 450 feet at either side and a depth of six feet. In connection with the new works, the lowering of Newcomen-bridge on the Clontarf-road must be alluded to. To effect this the old lock had to be moved higher up, and the old bridge replaced by one suited for the requirements of the tramway traffic. The arch of the bridge crossing the Canal was lowered five feet, and a new girder iron bridge crosses the railway at the same level. The Main Drainage Board wisely took advantage of the opportunity of the Canal being drained to make a main sewer under the canal and the railway above Newcomen-bridge at the low level required.
Happy, Mick?
Irish waterways history 
You beat me to it. I was researching the very matter myself and had spotted the height anomaly on the OS maps.
Well, it’s nice to have a bit of cross-checking! bjg
The next question is why were the bridges above Newcomen Bridge raised? I think I have the answer but am finalising the research currently.
I look forward to hearing the results. There is so much that we don’t know about the Royal (and indeed the Grand). bjg
Brian, Ewan
I am indeed impressed. I would have slept soundly tonight if it were’nt for this feckin “bridge raising” you speak of….!!
Mick
PS….Enjoyed the piece on Mallet’s “Incontinent Pantaloons”.