British Canals: Is their resuscitation practicable?

by Edwin A. Pratt

[To face page 128.

On this question of water supply, I may add, Mr John Glass, manager of the Regents Canal, said at the meeting of the Institution of Civil Engineers in November 1905:—

"In his opinion Mr Saner had treated the water question, upon which the whole matter depended, in too airy a manner. Considering, for instance, the route to Birmingham, it would be seen that to reach Birmingham the waterway was carried over one summit of 400 feet, and another of 380 feet, descended 200 feet, and eventually arrived at Birmingham, which was about 350 feet above sea level. The proposed standard lock, with a small allowance for the usual leakage in filling, would consume about 50,000 cubic feet of water, and the two large crafts which Mr Saner proposed to accommodate in the lock[12] would carry together, he calculated, about 500 tons. Supposing it were possible to regulate the supply and demand so as to spread that traffic economically over the year, and to permit of twenty-five pairs of boats passing from Birmingham to the Thames, or in the opposite direction, on 300 days in the year, the empty boats going into the same locks as the laden boats, it would be necessary to provide 1,250,000 cubic feet of water daily, at altitudes of 300 to 400 feet; and in addition it would be necessary to have water-storage for at least 120 days in the year, which would amount to about 150,000,000 cubic feet. When it was remembered that the districts in which the summit-levels referred to were situated were ill-supplied with water, he thought it was quite impossible that anything like that quantity of water could be obtained for the purpose. Canal-managers found that the insufficiency of water in all districts supplied by canals increased every year, and the difficulty of acquiring proper water-storage became enhanced."

Not only the ordinary waterway and the locks, but the tunnels and viaducts, also, might require widening. Then the adoption of some system of mechanical haulage is spoken of as indispensable. But a resort to tugs, however propelled, is in no way encouraged by the experiments made on the Shropshire Union, as told on p. 50. An overhead electrical installation, with power houses and electric lighting, so that navigation could go on at night, would be an especially costly undertaking. But the increased speed which it is hoped to gain from mechanical haulage on the level would also necessitate a general strengthening of the canal banks to avoid damage by the wash, and even then the possible speed would be limited by the breadth of the waterway. On this particular point I cannot do better than quote the following from an article on "Canals and Waterways" published in The Field of March 10, 1906:—

"Among the arguments in favour of revival has been that of anticipated rapid steam traffic on such re-opened waterways. Any one who understands the elementary principles of building and propulsion of boats will realise that volume of water of itself fixes limits for speed of vessels in it. Any vessel of certain given proportions has its limit of speed (no matter what horse-power may be employed to move it) according to the relative limit (if any) of the volume of water in which it floats. Our canals are built to allow easy passage of the normal canal barge at an average of 3 to 3½ miles an hour. A barge velocity of even 5 miles, still more of 6 or 7, would tend to wash banks, and so to wreck (to public danger) embankments where canals are carried higher than surrounding land. A canal does not lie in a valley from end to end like a river. It would require greater horse-power to tow one loaded barge 6 miles an hour on normal canal water than to tow a string of three or even four such craft hawsered 50 or more feet apart at the pace of 3½ miles. The reason would be that the channel is not large enough to allow the wave of displacement forward to find its way aft past the advancing vessel, so as to maintain an approximate level of water astern to that ahead, unless either the channel is more than doubled or else the speed limited to something less than 4 miles. It therefore comes to this, that increased speed on our canals, to any tangible extent, does not seem to be attainable, even if all barges shall be screw steamers, unless the entire channel can be reconstructed to far greater depth and also width."

What the actual cost of reconstruction would be—as distinct from cost of purchase—I will not myself undertake to estimate; and merely general statements, based on the most favourable sections of the canals, may be altogether misleading. Thus, a writer in the Daily Chronicle of March 21, 1906, who has contributed to that journal a series of articles on the canal question, "from an expert point of view," says:—

"If the Aire and Calder navigation, which is much improved in recent years, be taken as a model, it has been calculated that £1,000,000 per 100 miles would fit the trunk system for traffic such as is dealt with on the Yorkshire navigation."

How can the Aire and Calder possibly be taken as a model—from the point of view of calculating cost of improvements or reconstruction? Let the reader turn once more to the diagrams given opposite p. 98. He will see that the Aire and Calder is constructed on land that is almost flat, whereas the Rochdale section on the same trunk route between the Mersey and the Humber reaches an elevation of 600 feet. How can any just comparison be made between these two waterways? If the cost of "improving" a canal of the "model" type of the Aire and Calder be put at the rate of £1,000,000 per 100 miles, what would it come to in the case of the Rochdale Canal, the Tardebigge section of the Worcester and Birmingham Canal, or the series of independent canals between Birmingham and London? That is a practical question which I will leave—to the experts!

Supposing, however, that the canals have been purchased, taken possession of, and duly improved (whatever the precise cost) by State, municipalities, or public trust, as the case may be. There will then be the almost exact equivalent of a house without furniture, or a factory without machinery. Before even the restored canals could be adapted to the requirements of trade and commerce there would have to be a very considerable expenditure, also, on warehouses, docks, appliances, and other indispensable adjuncts to mere haulage.