The Beginning of the Age of Canal Building in Great Britain

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The Beginning of the Age of Canal Building in Great Britain

Overview

In 1760 the British Parliament approved construction of a canal to carry coal half a dozen miles (approximately 9.6 km) from the mines at Worsley to the city of Manchester. Until the eighteenth century, European canals were generally financed by the aristocracy and built for social or political reasons. But the agent who described the plans in the House of Commons argued that the new canal would make transporting goods easier and less expensive. The so-called Bridgewater Canal was the work of a self-taught engineer named James Brindley (1716-1772) whose name is synonymous with the early years of canal building. The success of Brindley's canal stimulated a new wave of construction that revolutionized Britain's transport system and contributed to the country's wealth over the next 50 years. Between 1760 and 1790, 25 new canal-building projects were begun. And in the short time between 1790 and 1794—a period known as canal mania—there were 46.

Background

Canals are artificial waterways that connect to rivers or other canals. First built in ancient times in the Middle East to supply drinking water and irrigation, canals came to be used to enhance the navigability of natural waterways. The Romans constructed canal systems in Northern Europe and Britain for military transport and drainage. Although European waterway development went into decline with the fall of the Roman Empire, it revived in the twelfth century. In 1373 the Dutch invented the pound lock, a tightly closed chamber that could be flooded or drained as needed to allow a vessel to pass between bodies of water at different elevations. The modern era of canal building in Britain coincided with the beginning of the Industrial Revolution and lasted until the arrival of the railroads.

England's geography is diverse, and canals often pushed through well-populated areas. Thus, man-made obstacles as well as valleys, rugged hills, and changes in water levels at the junctions of rivers and canals tested the ingenuity of eighteenth-century engineers like Brindley and William Jessop (1745-1814), whose Grand Junction Canal sliced through the Chiltern hills. The innovations builders devised to meet the challenges of the landscape included locks, tunnels, and bridges and aqueducts.

Although the British did not invent locks, during the era of canal building in Britain locks became bigger and more complicated. Locks were an essential feature of canals wherever builders encountered a change in the level of the ground. So-called staircase locks, which shared gates, were used where the contour of the landscape changed very suddenly, and where closely spaced locks were required. Flight locks were a later innovation that consisted of a number of locks put together. Side-by-side, or duplicate, locks helped to relieve bottlenecks on busy canals, and stop locks were used to keep water owned by different companies separate.

Because opening and closing locks led to the loss of water, engineers were eager to try alternatives such as mechanical lifts. The most common lift was the inclined plane, which consisted of a railed track up which a boat could be hauled. The first inclined plane was constructed in 1788 on the Ketley Canal, a private canal serving the Shropshire iron works. Not many of these lifts were built, and none survive.

Engineers who did not want to go around hills (as Brindley preferred to do) or over them had the option of cutting or tunneling through it. The Trent and Mersey canal built by Brindley was the first large-scale effort to take a canal through a tunnel. The technology for tunneling was borrowed from mining, and early examples were little more than openings through hills. Tunnelers followed a straight line from one point to another, sinking shafts and aligning them using a telescope. But the science of geology was unknown at the time, and tunnelers had no way of predicting what lay beneath the surface. Thus, they might encounter underground water, quicksand, and difficult rock formations. Sometimes tunnels did not meet up correctly. To keep costs low, early tunnels lacked towpaths, and crews were required to "leg" their way through, moving the vessel forward by pushing with their feet against the sides or top of the tunnel. This work was so exhausting that it required professional "leggers." Later tunnels did include tow paths, and barges were pulled along the canal in the same way as above ground, by horses, mules, or donkeys. An alternative to tunneling was simply to cut a gap through the hill.

Canals often cut across private property and existing roads, and parliamentary law required that no one be inconvenienced. Thus bridges became an integral part of canal building, to preserve passages from one part of an owner's land to another when a canal cut through it. Bridges were commonly made of brick, masonry, timber, or cast iron. Additional features prevented the tow lines from getting caught up in the bridge. Although aqueducts were not popular with canal builders because of the problems posed by the weight of the water and the need to keep the aqueduct watertight, these structures were the ideal solution to certain kinds of problems. For example, crossing a valley meant bringing a canal down to the lowest level, which in turn meant going to the expense of building locks. In building the Bridgewater Canal, Brindley dodged the problem by constructing the canal on a viaduct carried on arches across the valley.

A dry canal would bring transport to a halt, and canal builders were perennially concerned about water supplies. Specially constructed reservoirs, feeder canals, and water pumped from wells and rivers were some of the ways builders used to ensure a supply of water to the canal system. In addition, means were devised to conserve water already in the system. For example, side ponds at locks helped to compensate water lost in operating locks and through leakage and evaporation.

New kinds of structures related to the operation of canals arose. Canal cottages provided accommodation for the lengthsmen, tollkeepers, and locksmen who worked the canals. Maintenance yards were constructed to allow area engineers and craftspeople to perform maintenance tasks such as dredging (removing mud from canals to keep them navigable) and lock repairs. Just as canals were developed to serve industry, so industrial buildings, such as potteries and mills, sprang up alongside the canals. Wharves and warehouses were constructed to handle goods that needed to be transshipped or stored for the short or long term.

Impact

In the late eighteenth century Britain was still a small country. People did not often travel, and the needs they had for materials were usually satisfied by those close at hand. Not that they had much choice—road transport was inefficient, expensive, and unreliable. The coming of the canals would change all that.

Canal building in Britain signaled a new age of engineering, and engineering on a massive scale. Although the American War for Independence (1775-1783) diverted the cash Britain needed for construction projects, in the peace that followed a growing number of people in newly expanding cities needed coal for lamps, for heat, and for power. That coal needed to be transported inexpensively. The Bridgewater Canal showed what was possible by cutting the cost of coal in Manchester in half.

The development of the country's inland waterway system to meet these demands was perhaps the most important factor behind the Industrial Revolution. Prosperity fed on prosperity, as industries scrambled to find canal-side sites that would gain them low transport costs for materials (such as pottery) and the promise of a less bumpy ride for delicate finished goods. Where canals met rivers, new towns sprang up to supply the infrastructure required to manage the canals and the commerce they brought. The city of Birmingham, for example, owed its growth to its position at the heart of a canal system connecting London, the Bristol Channel, and the Mersey and Humber rivers. Heading into canal mania, industrialists, developers, and investors were more than satisfied. Without canals, the Industrial Revolution would still have occurred, but it would have been slower.

Insofar as the stated purpose of the canals was to bring trade and affluence to the regions along their banks, they succeeded. But not every individual canal project was a success. Building a canal required an Act of Parliament and money in the form of investment capital. At first, the people putting money into canal building were those promoting the canals and local backers. But during the height of canal mania in 1793, canal projects attracted speculators as jam does flies. So intent were speculators on quick profits that they backed any plan that had the word "canal" attached to it. Problems posed by the landscape were often poorly thought through, and developers frequently underestimated costs. Many schemes were stillborn, and the number of failures helped to diminish the reputation of canals in the public mind. Moreover, hoping to keep costs low, engineers built canals too small, and they failed to envisage the canals as an interlinked transport system—there was, for example, no national standard for the size of canal locks.

In 1796 the specter of war with France brought an end to the free flow of funds from speculators. By 1797 engineers had taken note of the advantages of "roads with iron rails laid along them" over navigable canals. With the coming of the railways, the inland waterway system in England was abandoned.

GISELLE WEISS