'Some Things Don't Change'
With the modern restoration and ongoing maintenance of the waterways, one of the most important factors has been the creation of new lock-gates. The dual pressure of being constantly underwater and controlling scug a huge, relentless quantity of water means that, no matter how impressive the workmanship, lock-gates need replacing every 25 to 30 years.
Traditionally made with oak, lock-gates are now made with tropical hardwoods such as greenheart and ekki (red ironwood). The construction process has changed only a little since the first Irish canals were built 250 years ago. In each instance, the original technical drawings are consulted before carpenters go on site to measure the old lock-gates and set to work creating new ones in their workshop.
Construction of lock gates in the workshop at Portna
Measurements are taken in accordance with the old Imperial System that was standard during the late Canal Age; these are converted into metric to produce a CAD (computer-aided design) drawing.
These timber gates are made using the very same process that existed when the first Irish canals were built 250 years ago
Complete with a signed and dated heel post, the new tailormade lock-gates are then fitted to the stone lock-chambers with steel brackets to forrtify the gate joints and increase longevity. The lock furniture - paddle gear, hoops, collars and cast iron fittings - are also either replaced or recycled in each instance.
When the lock-gates on the Lower Bann were replaced in 2017, the older ones were repurposed as benches along the new Lower Bann heritage trail. Old Lock-gates on the Shannon have likewise been reincarnated as canoe steps.
Waterways Ireland recently replaced the gates at Victoria Lock and Rooskey on the Shannon Navigation. And a new gate at Meelick was manufactured in the Netherlands, assembled in Munster Harbour, Portumna, and floated up to the lock on a pontoon.
Thomas Rhode's design for lock gates at Rooskey, 1845