The Canal & Rivers Trust maintains thousands of miles of waterways in England and Wales. Ben Cronin speaks to senior waterway engineer, North Wales & Borders waterways, David Clarkson about his job
Which parts of the canal network are you responsible for?
North Wales & Borders is one of 11 regions in England and Wales and has 182 miles of historic waterway with a variety of structures across its area totalling around 1,300 in number. Within this are 212 accommodation bridges, 106 locks, and others requiring continuing maintenance, repair and replacement. A significant proportion are listed structures.
How do you prioritise the work?
Throughout the year we have an inspection process whereby all the lengths of canal are inspected on a monthly basis. We’ve got a team of inspectors every month that cover the whole of the region’s canal system and they’re looking specifically for any faults and defects that might have occurred and our engineering team then prioritise those faults in terms of how urgent they are, be it a safety issue or an operational issue.
Describe a typical project
Replacement of items such as lock gates and lock chamber repairs are carried out during stoppages. These stoppages are programmed between October and February to minimise disruption to canal visitors. This does mean works are carried out in inclement weather and requires consideration for heritage repairs to be undertaken satisfactorily in the short periods when the locks are empty of water. These repairs are carried out by our own skilled craftsmen.
What do you most like about the job?
The historic aspects of the job are quite interesting. You know you find a culvert that you didn’t know existed. We’ve still got maps in our office from when the canals were built.
There’s a lot of investigative work. There are quite a few times when you hold something up and think: ‘how on earth does that go together?’
What is the standard of the archive material available?
There’s a lot of archive stuff where there are original drawings and microfiches, but you get so many different things crop up, even down to the land ownership. There’s a project in Chester where the canal cuts through a rock face where the city walls of Chester are built on top of the rock face. The rock face needs some work doing on it because bits of it are falling off and are a bit of a safety hazard to people coming through. We had to establish who owns the rock face. That’s the sort of things we get involved in as well as engineering.
What new technology do you use to maintain the assets?
Because the [canal] embankments show signs of movement in different areas we’re always looking to quantify that movement. One of the things we’re investigating at the moment is using the laser survey systems that have been used on the highways to see if it’s potentially able to be used to overlay our coastal erosion surveys to see if we can monitor the actual embankment profiles and come back at a later date and compare again.
Do you need some investment to do that or does it pay for itself?
We’re looking at [laser survey systems] from the engineering side of things but there is marketing potential in the system as well because you can get 3D profiles of the canals and members of the public could call them up – a bit like the Google Earth system.
And do you have any plans to use BIM on the canal network?
BIM is the sort of area that we’re looking at because where we’ve got heritage, environmental or stakeholder information relevant to the structures we’d like to feed that into the BIM model.