See history in the making

At the Canal & River Trust we’re always looking for ways to protect the traditional craft skills and heritage of our canal network, whilst also making the most of new technology, to ensure we’re maintaining our waterways as cost effectively as possible.

And as Dean Davies, our head of direct services explains, this winter, our ‘super-stoppage’ works at Wolverhampton lock flight will give us the chance to pilot a new way of producing replacement lock gates, that combine the best of both worlds.

“We look after 1,581 locks across our 2,000 miles of canals. And each of those locks has a set of gates, usually built out of oak timbers, that typically have a lifespan of around 25 years. Around 50% of those lock gates are listed structures, so they have to be rebuilt and replaced exactly to the original design. As most of the locks were built at different times, by different people, to different designs and specifications, very few gates are exactly the same. Every replacement gate is totally bespoke.

“Usually, we send a set of lock gate technicians out on site, to measure the existing gate and then produce a set of two-dimensional drawings. From there our carpenters in our workshop will build those lock gates entirely using traditional equipment, hand tools and craft skills that we’ve been using for years. This can take up to six weeks depending on the size of the lock gate. And some of the machinery we use dates back to the 1950’s, and is getting very out of date, and difficult to maintain.

“But recently we’ve been looking at using 3D technology to speed up the design process. By building a 3D model of a lock gate, we can cut each individual component of the gate exactly to size by a robotic, computer-controlled CNC machine and then deliver it to our joiners at the workshop, who can then assemble the gate and make any minor refinements, needed.”

Dean says they are piloting this new approach at Wolverhampton because the single gates on this narrow flight are relatively simple; a little like a door on a hinge. But if it works well here, then in future, this 3D technology could be applied to lock gates across the network.

“It’s not even limited to timber,” explains Dean. “For instance, we’ve just bought a plasma cutter for our workshops that can produce bespoke steel components such as fender plates and strengthening struts from a 3D model. Compared to buying these items in from other manufacturers, the in-house machine should pay for itself in just eight months.

“We’re also looking at the 50% of lock gates that are not listed and protected. We might be able to give these gates a longer life of up to 50 years by introducing other materials like steel or fibre reinforced plastic into the design. And all these items could be produced and manufactured much quicker by using this modern 3D design process.”

As well as renovating four locks, our volunteers and corporate partners will be helping us to tidy up the entire lock flight during the super-stoppage, clearing litter, tackling graffiti, and making the local towpath an even more enjoyable place to be.