Slow Routes
A canal is a staircase of water and it moves at the speed of a lock
Artificial waterways were engineered around gradient and water supply rather than around distance, and every characteristic of travelling on one follows from those two problems.
By Samar Bhatia4 min read
A canal exists because water won’t climb
A river finds its own level and a canal has to be given one. The entire art of building an artificial waterway is holding a flat sheet of water at a series of fixed heights across a landscape that isn’t flat, and then providing a way for boats to move between those heights.
That is what a lock does: it’s a chamber with a gate at each end, filled or emptied to lift or lower a boat between two levels. It is a beautifully simple device and it is also the reason canal travel is slow, because each passage takes as long as it takes to move that volume of water.
Where engineers could avoid locks they did, at considerable expense. Contour canals wander enormous distances to stay on one level, and later routes cut straight through with embankments, cuttings, aqueducts and tunnels, which is why two canals built fifty years apart can look like different technologies.
Water supply is the constraint nobody expects
Every time a boat goes down a lock, a lockful of water leaves the upper level and is lost downhill. A busy flight of locks therefore drains its summit continuously, and the summit is by definition the place with the smallest natural catchment feeding it.
Solving that produced some of the most impressive parts of the system: feeder reservoirs on high ground, pumping stations lifting water back up the flight, side ponds that recover part of each lockful, and elaborate rules about not wasting a chamber. Restrictions on lock use in dry summers are the modern version.
It also explains why some canals died. A route that could not guarantee water in August was unreliable for freight regardless of how well it was built, and unreliability was fatal once railways offered a service that did not depend on the weather at all.
The pace is not a lifestyle choice, it is a physical limit
Boats on narrow waterways travel at a walking pace and are usually required to, because a hull moving faster in a shallow confined channel drags water with it and erodes the bank. The speed limit is protecting the infrastructure rather than the passengers.
On top of that, the journey time is dominated by locks rather than by the straight sections. A route with a long flight in the middle can take a whole morning to cover a couple of kilometres, and planning a day by distance rather than by lock count is the standard beginner error.
This makes canal travel a genuinely different mode from anything on land. You can step off and walk beside the boat, and often walk faster than it. Reaching somewhere is not the point in any practical sense, because almost every canal destination is quicker to get to by road.
The towpath is frequently better than the water
Because the path was built for horses towing boats, it is continuous, level, hard-surfaced in many places and follows the gentlest possible line through the landscape. That makes it one of the best walking and cycling corridors available in any country that has an old canal network.
It also passes through the backs of towns rather than the fronts. A canal was industrial infrastructure, so it runs behind the mills, past the goods yards and under the roads, and the view from it is the working side of places that present a quite different face to the street.
Access varies more than people assume. Some networks have fully public towpaths, some are permissive routes that can be closed for maintenance, and on some continental waterways the bank is not walkable at all. Checking before planning a long linear walk avoids an awkward detour around a padlocked gate.
What a canal journey actually asks of you
Hiring a boat is the usual way in, and the learning curve is short but real: handling a long hull with no brakes, working locks in the correct order, and reading the depth of an unfamiliar channel. Operators brief people on all of it, and most of the difficulty is patience rather than skill.
It is physical, which surprises people who imagined a floating holiday. On a lock-heavy route somebody is winding paddles, pushing gates and climbing ladders repeatedly all day, and a crew of two on a flight of twenty is doing a genuine day of work between meals.
The alternative is to use the canal without a boat at all — walking a section, cycling a corridor, or taking a scheduled trip through a famous flight or tunnel. That gives you the engineering and the landscape without the responsibility for a large steel object, and for a short visit it is often the better trade.
Common questions
How far can you realistically travel on a canal in a day?
It depends almost entirely on locks rather than distance, so the useful unit is hours of cruising plus a fixed allowance per lock. Hire operators publish suggested routes in days for exactly this reason, and their estimates are usually honest because unhappy late returns cost them money.
Do you need a licence to steer a hire boat?
In many countries no formal qualification is required for a standard hire craft, with the operator providing instruction instead, but rules differ by country and by waterway and some require a certificate or a temporary permit. The hire company will state what applies before you book.
Why are some canals much wider than others?
Because they were built for different boats, and the width of the locks fixed the size of the craft forever afterwards. Networks that standardised on a narrow gauge could never carry the larger barges used elsewhere, which limited their commercial life and is one reason they survive as leisure routes.
Senior writer, The Next Postcard
Samar has written about cities, slow routes, rail & road for most of the last decade and is happiest when a piece answers the question completely.
