IF YOU want to take life easy, things don’t get much more sedate than a sunny afternoon spent on canals, chugging through the British countryside on a slow boat to nowhere in particular. But the tranquillity is deceptive: after 50 years of neglect, Britain’s crumbling canal network is undergoing a revolution.
When the engineers of the Industrial Revolution strode about the country undertaking heroic feats of construction, the waterways were among their most impressive creations. Their great aqueducts and tunnels and flights of locks helped burgeoning industries transport their raw materials and finished goods, and supplied the water needed to run their steam engines. By the end of the 18th century the network stretched over 8000 kilometres and carried some 30 million tonnes of materials every year.
Today’s revolution is different. Tourism and leisure are leading the way, followed by plans for a new national water grid, a telecommunications network and even a modest amount of freight. What remains the same, however, is the sheer ambition of the engineers, this time aiming to build a network fit for the 21st century.
Advertisement
For a while it seemed that the canals had had their day. The post-war years saw many of them abandoned, filled in, or severed by new roads. Although British Waterways – an organisation part-funded by the government – was charged with preserving the network, chronic underfunding meant that much of the essential repair and conservation was left to volunteers.
But by the mid-90s, BW and its partners were getting the message through that the canals could make a valuable contribution to leisure, the environment and the economy. For example, BW linked up with telecoms company easynet to set up an optical fibre network along its towpaths. These cables carry over 2000 optical fibres, providing enough capacity for everyone in Britain to make a phone call simultaneously. And BW began ploughing the money it made from this venture back into its other schemes. Together with new funds from the European Union, development agencies and central government, this has allowed BW to unlock restoration projects dating back decades.
The result is a revitalised network, where stretches of navigable water are being built and restored at a rate not seen since the original system grew up. BW and The Waterways Trust, a charity that aims to revitalise Britain’s canals have this year highlighted restoration and construction projects valued at more than £500 million. The two-stage scheme covers over 500 kilometres of canals and waterway structures.
Eight projects will be completed this year, opening up over 350 kilometres of canals. They include some impressive structures. The Anderton Boat Lift in Cheshire, for example, is a Scheduled Ancient Monument. The lift was built in 1875 to carry cargo boats between the River Weaver and the Trent and Mersey Canal, almost 17 metres above. It closed in 1983 after the structure became unsafe but reopened this spring following a ÂŁ7 million repair programme.
Of all the projects, however, it’s the Falkirk Wheel that demonstrates a vision reminiscent of the original canal builders. The wheel is the world’s first rotating boat lift, standing almost 40 metres high and linking the Forth & Clyde and Union canals between Glasgow and Edinburgh. Opened in May this year, it forms the centrepiece of the £84.5 million Millennium Link project, which will restore a coast-to-coast waterway link running right across the Scottish lowlands.
“A flight of 11 locks originally linked the two canals, but we decided we needed something special there, something really modern,” says George Ballinger, chief engineer on the wheel. “We wanted something with a definite wow factor.” £17 million later they have achieved it.
Boats are loaded into two giant caissons at the top and bottom of the wheel (see Diagram). The wheel then rotates 180°, so that the two caissons swap places. Each caisson weighs 50 tonnes and can hold up to 250 tonnes of water and around four average-sized canal boats. Together with the rest of the wheel, the whole thing weighs in at a massive 1800 tonnes, yet it takes only the same amount of power as two electric showers (about 20 kilowatts) to shift it.
“It’s possible because it’s perfectly balanced,” says Ballinger. And because any boat displaces its own weight in water, the system always remains balanced. “Archimedes sorted it all out for us,” he says. “It wouldn’t matter if you had an aircraft carrier at the top and a canoe at the bottom.”
The rotation takes less than five minutes, although the entire loading and unloading cycle takes more like 15. This compares with several hours to get through the original flight of locks. Locks also have the disadvantage of using a lot of water. Ballinger says: “The Union Canal is not particularly well-endowed with water. The wheel, of course, doesn’t consume any water at all.”
Phase two of the national expansion plan involves a further nine projects around the country, most of which are restorations or the completion of projects planned over 100 years ago. But they also include the first new canal to be designed for a century, the Bedford & Milton Keynes Waterway. This will link the Grand Union Canal in the heart of England to the River Great Ouse, joining the main canal network to the waterways of East Anglia.
All this investment can be commercially justified by leisure and tourism alone: around 10 million visitors now spend ÂŁ1.5 billion each year on or around the canals, and the Anderton Boat Lift, for example, is predicted to attract over 50,000 visitors a year. But will the changes benefit anyone but tourists and day-trippers?
John Taylor is one of the people charged with ensuring that today’s canals provide far more than just a good day out. As BW’s national water development manager, Taylor is responsible for Water Grid, an ambitious scheme to transform the waterways into an integrated network for moving water around the country.
In the early 1990s, the National Rivers Authority undertook a strategic review of water supplies in England and Wales. It predicted there would be shortages in the south and east within 25 years. But water resources in these areas were fully developed, so Taylor realised some way would need to be found to bring water in.
Unlike electricity, however, water is heavy and expensive to shift about. Local water companies normally source and supply water within their own areas, because building and maintaining long pipelines and pumping stations makes other options uneconomical. So Taylor came up with the idea of using the canal network.
Britain’s canals hold an estimated 200 billion litres of water and BW owns water resources all over the country, including 89 reservoirs, a handful of boreholes and a number of rivers and streams that were diverted into the canals when they were built.
Moving water along a canal takes very little energy compared with moving it through a pipe. Friction losses are proportional to the square of the velocity of a fluid through a pipe or channel. Since a narrow canal is roughly 90 times the cross section of a typical 600-millimetre water main, velocity and friction losses are relatively small. This minimises pumping costs.
It isn’t a new idea. The canals have always been used to move water, carrying it under gravity away from sources such as rivers and supplying the steel and textiles industries, for example. The city of Bristol already receives over half its water from the River Severn via the Gloucester and Sharpness Canal. And with pumping, water can be transported to the summits of the network when needed.
However, for Water Grid to succeed, the control and monitoring of the water in the network must be coordinated across the whole system. According to Taylor, implementing the control system will cost upwards of £20 million and BW can’t afford to go it alone.
In order to fund the system, BW is to join forces with either private utility company United Utilities, or Anglian Water group. The final choice will be announced as żěè¶ĚĘÓƵ goes to press. The plan is that the partner will supply both the financial muscle and water treatment expertise to enable Water Grid to offer customers a reliable, locally treated water supply.
BW has already picked a former training centre in Warwickshire as the grid’s headquarters. It will be linked by a huge control and data acquisition system to controls on the sluices, locks and pumps distributed around the network.
The control system will be built up using a mix-and-match approach. Some flow monitors, for example, may need to send readings back to the centre continuously, in which case a dedicated line might be needed. Other readings, such as the level in a reservoir, may only need to be taken once a day, and these readings could be sent over the public phone network. Some remote sensors may need to be linked into the system via radio transmitters.
The key factor limiting the capacity of an individual canal is BW’s requirement that the character of the canals remains unchanged. Push the flow rate too high and you’d need to reinforce the canal banks and locks to prevent damage. “We think that between 50 and 100 million litres each day would be appropriate so we can keep the canals looking the same,” says Taylor.
Even operating within these limits, the network will need extra pumping stations and canal improvements costing a further £10 million. For example, BW will fit pumping stations and pipelines to take water around some lock flights, rather than through them. This should ensure that the leisurely pace of normal navigation won’t be affected.
Yet not everyone wants life on Britain’s canals to remain so unhurried. In a policy document published in 2000, the Department of the Environment, Transport and the Regions announced that it was keen to move 3.5 per cent of freight currently carried by road onto the inland waterways – some 60 million tonnes per year. Of this, much less than half is likely to end up on the canals, with the rest on rivers and estuaries.
But the government’s enthusiasm to get freight back onto canals has left some organisations responsible for the upkeep of the network a little nervous. In a report published last year, the Association of Inland Navigation Authorities expressed doubts that the government’s target could be met without significant investment. At present, it suggests, the canal network could handle up to 12 million tonnes per year. But to maintain even this modest level would mean reducing or even halting recreational use on some canals during working hours. “The key thing is that it’s the estuaries and large river navigations that are sustainable for freight movements,” says Ian White, BW’s north-east regional director and freight expert. “On traditional canals there’s not so much scope.”
Certainly small, slow-moving canal boats are never going to be a viable way to move perishable goods such as food. A standard narrowboat carries just 25 tonnes and moves at only a few kilometres per hour. Yet for limited amounts of low-cost, bulky items such as timber, coal or waste material for recycling, they could be just the job.
One type of load that everyone is keen to get off the roads is what’s known as an abnormal indivisible load (AIL), anything over 5 metres wide, 27.4m long or 150 tonnes. Anyone wanting to transport one of these by road needs special permission, and if you get stuck behind one you won’t be going anywhere fast. AILs typically include components such as industrial castings or electrical transformers for power stations.
Last month, an ÂŁ8.5 million government grant enabled transportation specialist Wynns to begin construction of its Multi Purpose Pontoon (MPP), a seagoing barge designed to handle AILs. When this is completed in 2004, it will carry up to three loads of up to 400 tonnes each.
The MPP will also be able to carry a second vessel – named Inland Navigator – in its belly. Inland Navigator is a river barge that has been specially converted to carry AILs. It will float in and out of the MPP and will be able to travel further inland via narrower waterways.
Admittedly, AILs don’t crop up every day. Tim West of Wynns estimates that the MPP will carry 400 loads over its planned 20-year lifetime and some of these will still have to make part of their journey by road. At 16.5 metres wide, the MPP is also far too big for all but the very largest ship canals. Despite this, West says that the project could still have an impact on freight.
“These loads could be a catalyst,” he says. “If the infrastructure is there for AILs it can be used for other cargo. If you can get 300 tonnes through a lock you can easily get smaller loads through.”
After being in real danger of disappearing altogether, the canals have been given a new lease of life. “It’s staggering to think about what the original builders did,” says Ballinger. “And it’s nice to know that we’ve still got the ambition to think about the big picture.”
