Picture a canal in Britain and you may well think of ducks and swans bobbing about, locks or a lovely old pub by the towpath.
But there are also more than 50 tunnels on the country’s 2,000-plus miles of waterways, ranging in length from just 25 yards to more than three miles.
The construction of tunnels to overcome geographic hurdles that were too great for locks was one of the most difficult tasks faced by canal engineers in the 18th and 19th centuries.
It was back-breaking and dangerous work, in some cases deadly, with the canal navigators, or “navvies”, blasting and digging their way through hilly terrain.
In one tragic incident, 14 of these labourers died when a section of the Blisworth Tunnel in-Northamptonshire collapsed in 1796.
However, today the canals and tunnels are enjoyed by hundreds of thousands of boaters, both owners and hirers, each year and the tunnels are regarded as engineering marvels.
We asked hire firm Drifters for its pick of the best bores to transit by narrowboat, or in some cases walk along the towpath (not all tunnels have one).
1. Falkirk Tunnel, Stirlingshire - 689 yards
Scotland’s longest canal bore, on the Union Canal in the south of the town, was completed 201 years ago.
The navvies carved and blasted through the hillside because the local landowner, William Forbes of Callendar House, campaigned to Parliament against the overland route, which would have ruined the view from his house!
There’s room for two narrowboats to pass in the tunnel, and it has a towpath and a colourful lighting system to highlight the Georgian engineering.
Don’t miss the Falkirk Wheel nearby, which lifts boats 79ft between the Union and the Forth and Clyde canal.
Opened in 2002, this engineering marvel reconnected the two waterways for the first time since the early 1930s when a flight of 11 locks fell into disrepair and was dismantled.
The wheel is the only lift of its kind in the world and attracts around 400,000 visitors annually. It’s so well designed, one lift only needs the same amount of energy as it would take to boil eight household kettles.
2. Standedge Tunnel, West Yorkshire/Greater Manchester - 3.22 miles
Bored beneath the Pennines between Marsden and Diggle, this beast on the Huddersfield Canal is the longest, highest and deepest tunnel on the British canal system.
Hewn through solid rock, it took the navvies 16 years to dig and opened in 1811.
In the 20th century, the canal fell into disrepair, becoming unusable by 1948. After a long restoration programme, both the canal and tunnel were reopened in 2001.
It takes around one hour 20 minutes to travel through Standedge Tunnel and narrowboat holidaymakers need to book their passage through with a Canal & River Trust chaperone.
3. Blisworth Tunnel, Northamptonshire - 1.75 miles
On the Grand Union Canal at Stoke Bruerne, it’s the second longest fully navigable tunnel on the canal system. Construction began in 1793 and it was opened in 1805.
It’s wide enough to accommodate two narrowboats, so it’s not necessary to book a chaperoned passage.
4. Chirk Tunnel, near Wrexham - 460 yards
On the Llangollen Canal by the England-Wales border, it has a towpath and is designed for a single narrowboat.
It opened in 1802, and boaters are required to show a light, so others can see if there is a vessel already transiting before entering.
5. Harecastle Tunnel, Staffordshire - 1.66 miles
Designed by Thomas Telford, it was completed in 1827. Passage through the tunnel which is on the Trent and Mersey Canal is in a single direction at a time, because only one of the two original tunnels is in operation.
Access is controlled by the Canal & River Trust’s Tunnel Keeper Team, allowing groups of boats to pass through in convoy, before reversing the flow of traffic.
6. Ashford Tunnel, Talybont-on-Usk, Powys - 375 yards
This Monmouthshire and Brecon Canal feature, dating from 1800, is wide enough for just one narrowboat and there is no towpath.
When horses pulled canal boats laden with cargo, they were detached before the tunnel and led over the hill to the other end.
To move the boat through the tunnel, the crew would lie on planks and use their feet to push on the tunnel walls, a technique known as legging.
At some of Britain’s long tunnels, professional leggers were available.
7. Netherton Tunnel, West Midlands - 1.72 miles
It was the last tunnel constructed during the canal age – opened in 1858 – and was built with towpaths on both sides. Near Oldbury, it’s part of the Birmingham Canal Navigations.
8. Wast Hills Tunnel, Birmingham/Worcestershire - 1.55 miles
This tunnel on the Worcester and Birmingham Canal was designed by Thomas Cartwright and completed in 1796. It’s wide enough to accommodate two narrowboats, so it’s not necessary to book a passage through it, but there is no towpath.
9. Braunston Tunnel, Northamptonshire - 1.16 miles
Also dating from 1796 it’s on the Grand Union Canal and also wide enough to accommodate passing narrowboats. Like Wast Hills, there’s no towpath.
Book the holidays
Drifters offers more than 550 boats for hire, operating from 45 bases across England, Scotland and Wales; 2023 hire prices start at £590 for a short break, £815 for a week on a boat for up to four people.
Narrowboats range from 32ft to 70ft and can accommodate up to 12 people. All Drifters operators provide hirers with life jackets and boat-steering tuition. Find out more at drifters.co.uk, canalrivertrust.org.uk and scottishcanals.co.uk.
