The view from the towpath

On one of the coldest mornings for decades an exposed stretch of canal was not a place to linger without good reason. The water had frozen to a sheet of ice nine or ten inches thick. In places, the towpath had become impassable to everyone except the brave. But on that bone-chilling day, although yet more snowfalls and sub-zero temperatures were forecast, a team of workmen had no choice but to set up base on the canal banks.

The passage of two centuries had already made this stretch of the Leeds-Liverpool canal look almost as natural as the nearby River Aire and now the ice and snow had all but completed the job. In the cold early morning light, only a set of three-rise locks suggested that this was a man-made watercourse.

The timber gates had rotted away and bits of them had crumbled into the lock –- given a last helping shove by the sheet of ice – and the workmen had come to try and repair the lock in time for the canal's reopening to narrow boats.

The operation to remove the old gates and install eight new ones was setting back British Waterways 300,000. In Yorkshire, it costs them around 4.2m a year to keep the canal network in working order. Nationally, the figure is 32m.

Of the 2,200-mile network of waterways in mainland Britain, the 127-mile Leeds-Liverpool Canal is the longest.

Like the Settle-Carlisle railway line, it is one of the great icons of the North, but as the canal approaches its 200th birthday it requires an increasing amount of maintenance.

The waterway was initially conceived by Bradford merchants and landowners to move loads of coal and limestone in the Aire Valley.

But it soon dawned on them that, although coal to drive the engines powering factories and mills would be the primary load carried on canals, extending the route across the Pennines would allow Bradford's worsted goods to reach cargo ships on the Mersey and open up trade with the Americas.

The first sods were turned at Hurst Wood, near Shipley, in 1770. And soon afterwards work began on the Lancashire side at Newburgh and Aintree. When it was finally completed in 1816, the canal would help make Leeds and Bradford two of the greatest cities of the industrial revolution.

Among its 91 locks, the five-rise staircase at Bingley are the most famous. The three-rise locks at Newlay, a few miles to west of Leeds city centre, are less well known and it was these that had to be repaired this year to keep the waterway open for the spring and summer narrowboat traffic.

Mike Marshall, who is maintenance manager for all the canals in British Waterways' North East region, describes the canal network as a heritage monument, in its own way as an important a part of the region's history

as buildings like York Minster or Harewood House.

In fact, work on the Leeds-Liverpool began just as architects John Carr and Robert Adam were putting the finishing touches to Harewood.

"Replacing lock gates like those at Newlay is about as expensive as our work gets," Mike says. "But it's something we have to do on average about once every 25 years. In the region I'm responsible for we have 150 locks, and since each pair of gates costs 40,000 to build and fit you can see how expensive it is to keep the waterways open. Locally, we can only afford to replace maybe 10 pairs of gates in any year."

Most of the gates for northern canals are built at British Waterways' Stanley Ferry workshops in Wakefield. Each gate weighs up to five tons and measures around four metres in width and up to

10 metres in depth.

The design sticks to the template laid down two centuries ago, although some new materials have been tried. In particular, the traditional oak is replaced by more sustainable hardwoods. And if you look at new gates closely you'll spot some steel strengthening inserts, which, Mike says, bind the timbers together to "stop them falling apart and give the gates a bit of extra life".

The other big problem with the ageing Leeds-Liverpool is that it has become prone to leakage, especially on the long man-made embankment that was constructed to carry the canal up the Aire Valley between Keighley and Skipton.

"Finding these leaks is a major task, and never easy," Mike says. "Often we rely on the expertise of staff that's been gained by them over many years and, in some cases, even passed down from father to son."

Leaks are usually found by visual evidence, water trickling or gushing out of an embankment. But the point at which the water escapes is often some distance from the actual hole in the canal's lining. British Waterways then section off different parts of the canal and use environment-friendly dyes to see if the colour flows out from the leakage.

A lot of it is trial and error. When the hole is eventually pinpointed, the material used for sealing the canal is still puddle clay, which was used as the lining 200 years ago.

It is a constant challenge for British Waterways to find the money that keeps open the Leeds-Liverpool and other canals. The income received from narrow boat users is never enough and government grants have become vital.

The whole issue of waterways finance is under review and there is a suggestion that British Waterways might join the so-called "third sector" in Britain, with a charitable status and a remit similar to that of the National Trust. A report on the canals' future will be published later this spring.

In the meantime, work goes on along the Leeds-Liverpool and other waterways. Each one is getting an annual spring clean, with towpaths tidied and overhanging vegetation cut away.

Says Mike: "Our maintenance work on the canals is limited by a design that was first laid down a couple of centuries ago. But that's as it should be. We must always be sympathetic to the original design. And the more we work on the waterways, the more we come to respect the genius of the engineers who built them with such limited technology at their disposal."

YP MAG 10/4/10