Ephemera 9: the flash lock at Killaloe

As part of its new mooring scheme at Killaloe, Waterways Ireland has commissioned contractors (L&M Keating Ltd) to carry out various works including the installation of a lock at the upper end of the canal, beside the Phoenix boathouse and just downstream from the Pierhead. The lock is to control access to the canal; presumably the stop planks in the existing lock chamber will be removed, allowing boats to pass down under the bridge.

The lock under construction

As I understand it, this lock is to have a single pair of gates. Boats wishing to pass through will tie up temporarily and use a squawk-box (or similar technological marvel) to communicate with the bridge-keeper at Portumna, who will cause the gates to be opened and then, presumably, closed after the boat has passed through. This system will prevent the use of the canal by cads and bounders using jetskis, speedboats and other excrescences.

Stanked off and pumped out

However, the water through Killaloe Bridge has a gradient or slope, especially in flood and when Ardnacrusha power station is running. The canal above the lock will be at the higher level; the canal below the lock will be fed from the bottom end, where it rejoins the river. So is there not likely to be a difference in height at the lock? Is this the equivalent of a flash lock?

I’m sure there is an engineering answer to this; I would welcome enlightenment.


3 responses to “Ephemera 9: the flash lock at Killaloe

  1. Pingback: industrialheritageireland.info » Blog Archive » Shannon Navigation - Flash lock at Killaloe?

  2. damien sherlock

    Hello. Is there any old pictures or plans of the lower part of the canal in killaloe. I.e.the part that is now submerged since the completion of the shannon scheme.
    Cussane lock is of particular interest as I recently did a dive there with limerick subaqua club.

  3. You can see the general layout on the OSI map here. The National Library has a photo here and here; I put both in to show the variants. Thomas Rhodes did a plan of the river from Limerick to Killaloe in 1832; there is a Google Books version but unfortunately they didn’t unfold the maps before scanning them and the bit you want is not visible.

    But your best bet is probably to contact the Waterways Ireland Archive.


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