How do you maintain Wales’ longest canal tunnel?

Reporter Jamie Bowman goes underground at the Llangollen Canal World Heritage Site for a crucial examination of Chirk Tunnel, with the Canal and River Trust’s chief inspectors…

With more than a million individual bricks and 200 years of history to contend with, inspecting and maintaining Chirk’s famous canal tunnel is no easy task.

But as one of the UK’s popular waterways, ensuring the 11-mile long Llangollen Canal is in good working order is an essential duty for the engineers from the Canal and River Trust whose job it is keep a watchful eye on the country’s 2,000 mile-long canal network.

This week saw the Trust’s specialists jump aboard a boat which traveled the length of both the 421m-long Chirk tunnel and the 174m Whitehurst tunnel to assess if any structural changes had taken place or if any urgent repairs were needed to those many bricks.

“What we are doing is called a principle inspection,” explains engineer Chris Reynard as we glide into the gloom of the tunnel.

“We carry it out every five years and we’re basically making sure there isn’t anything that might fall down on the public’s head as their boat travels through the tunnel.

“It’s like an MoT for the tunnel and we have a very close look at the brickwork both above the water level and below.”

While his colleague pokes around the bricks with a special implement (or it may just be a stick) checking for cracks and leaks, Chris reveals the many issues they face when dealing with a construction which first opened in 1805 following years of work by engineering legends Thomas Telford and William Jessop.

“The bricks weren’t actually the greatest quality when it was built back then – so we need to check the lining where we think they might be loose,” he says.

“When boats go past they produce a sucking action which can pull the bricks out. Once that begins, it can quickly unravel. This was the case in this tunnel a few years ago when it had to be repaired.”

If the dark and dank depths of the tunnel aren’t eerie enough, Chris also has to check that no bats have made their home in its secluded surroundings.

“This time of year bats may come in to roost – so we have to be aware of them and are trained in how to look for them.

“It may sound a silly thing but you cannot interfere with bats and have to be very careful when you find them.”

It takes around 10 minutes to pass through the tunnel leaving enough time for a quick history lesson from Lynn Pegler, of the Canal and River Trust, who points out that the tunnel was the first British canal tunnel to have a towpath running alongside.

To save money, earlier canal tunnels had narrow bores (openings).

Boats were propelled by leg power with boatmen or hired hands lying on the roof of the boat and effectively walking along the roof.

While the towpath enabled faster passage of boats, its width restricted the tunnel to one-way traffic. However, the tunnel is so straight that a boat entering one end can be seen from the other.

“It’s an awe inspiring piece of engineering,” marvels Chris. “No-one really stops and looks at it closely like we do but they should do because the brickwork is incredible.

“It’s hardly changed since the day it was built and the bricks behind the ones we’re looking at are actually pretty pristine.”

It took until the 1980s for the Llangollen branch of the former Ellesmere Canal to be fully refurbished but the tunnel can now proudly claim to be part of a UNESCO World Heritage Site and Grade II listed.

“Funnily enough there are more canal boats on the system now than there were back in the industrial revolution,” adds Chris.

“Since the 1980s the canals have booming with more and more restoration work taking place and some wonderful canals are being brought back to life.”

It’s estimated that Wales’ historic canals make an annual contribution of £34m and support 800 jobs in local businesses but with funding being cut across the board it remains a challenge maintaining something many regard as ‘a national treasure’.

“Over the winter from November to Spring is when the Canal and River Trust does the majority of its maintenance because obviously the canals are a lot quieter,” says Lynn, when we are back on dry land at a sun-bathed but chilly Chirk Basin

“We are spending about £38m across England and Wales on repairing lock gates, bridges, tunnels, aqueducts and reservoirs.

“We are a charity and although we do get a government grant we are very reliant on people donating, becoming ‘Friends’ and volunteering with us as well so we’d love for more people to engage with us.”

“Take a look around – it’s absolutely gorgeous and we’re so lucky. We want that to continue.”

For more information about how to support the vital work of the Canal and River Trust by donating or becoming a ‘Friend’, check out www.canalrivertrust. or call the customer services team on 0303 040 4040.

Video and pictures by Rick Matthews