The ordinary barges on the Leeds and Liverpool Canal have been utilised as tugs by putting in small engines of just sufficient power to drive a screw propeller as large as could be made available without a large percentage of positive “slip,” each tug carrying a paying cargo. When the first barge was fitted up in this way, it was found that it would tow two others very well at two miles an hour. In some parts of the canal where the depth is a little greater the speed would rise to 2½ and 2¾ miles an hour; and under similar conditions, with only one barge in tow, as high as 3¼ to 3½ miles an hour. At the latter speed, however, the displacement sets up a rolling wave along banks, which does injury, whereas at 2 to 2½ miles an hour there is no perceptible disturbance of the water at the sides, and only a very slight disturbance in the centre.
A number of these steam barges are now employed on this canal, in addition to one for towing through Foulridge tunnel, one mile in length. This tug has both ends alike, with two propellers, one at the bow and one at the stern, as well as a rudder at bow and stern, so that the boat does not require to be turned about at each journey. Prior to the adoption of this tug, all barges had to be worked through the tunnel by men, who lay on their side on the gunwale of the boat, pushing it along with their feet against the tunnel wall, and taking 2 to 2¼ hours to travel the mile, whereas the tug tows two and three loaded barges at a time the same distance (one mile) in twenty to twenty-five minutes, the only hands required being the engineer and helmsman. The engine and boiler are placed as far aft as possible. The form of propeller is the result of a very exhaustive and costly series of experiments. With full-size ones in actual work, it gives the best results in shallow waters. It would not, however, be well adapted for deep-water towage. The helmsman can perform the following duties without leaving his helm, viz., start, stop, or reverse the engines, lower the funnel at bridges, blow the whistle and use the auxiliary steam jet for funnel. He can also observe the conditions of his boiler, for he has the water-gauge and steam-gauge in full view before him.
Mr. Ald. Bailey, of Salford, has given the following interesting details of the cost of a steamer for twenty-four hours’ work, towing two barges fully loaded, on the Leeds and Liverpool Canal:—[271]
| Cost of Steamer. | |||
| £ | s. | d. | |
| One captain | 0 | 4 | 8 |
| One mate | 0 | 4 | 8 |
| Two ordinary hands | 0 | 8 | 0 |
| Gas coke for engines: 24 cwt. at 6s. 8d. per ton | 0 | 8 | 0 |
| Tallow (2 lb.) at 5d. | 0 | 0 | 10 |
| Oil (2 quarts) at 10d. | 0 | 1 | 8 |
| Stores, waste and lights | 0 | 1 | 0 |
Cost of Two Barges. | |||
| Two captains at 4s. 4d. | 0 | 8 | 8 |
| Two ordinary hands at 4s. | 0 | 8 | 0 |
| Five per cent. interest, and 10 per cent. depreciation, | |||
| on first cost of steamer and barges (£1000) for one day | 0 | 8 | 3 |
| Fifteen per cent. of steamer and barges for repairs per day | 0 | 8 | 3 |
| £3 | 1 | 8 | |
The distance averaged in twenty-four hours (including locks) was 40 miles. The weight carried was—steamer, 35 tons; barges, each 40 tons; total 115 tons. The cost was about one-sixth of a penny per ton per mile.
Mr. Bartholomew, of the Aire and Calder Navigation, has introduced a system of a train of boats about ten or twelve in number, each carrying about 40 tons, 20 feet long, 16 feet wide, and 7 feet 6 inches deep, propelled by a steam tug.
By having a tug behind the train of boats, greater control of the steaming power is obtained. The boats are threaded together by means of wire rope controlled by two cylinders which are self-acting, and are under the charge of the man who is steering. By lengthening and shortening the wire ropes on each side of the train, it can be guided to go to any curve by making it convex or concave, the train being left to rise and fall vertically according to any little variation of headline. Buffers are attached to the ends of the boats, which have a tendency to bring them back again into line in case of any slight disorganisation caused by wind or water, the full control of the train and its direction being under the guidance of the steerer.
This system, however, could not be introduced on many of the canals in England, unless larger locks were made, or inclined planes to get from one level to another. The system has been well described as a train of waggons on water without wheels.
On the Gloucester and Berkeley Canal, Mr. Clegram found that, after allowing 15 per cent. for interest and depreciation, the cost of steam haulage amounted to 1⁄11th of a penny per ton per mile, being a saving of two-thirds as compared with horse power. With a heavier trade, however, which allowed the barges to be more generally employed, the work was done for 1⁄16th of a penny per ton per mile.
In a number of cases both chain and wire rope haulage has been tried unsuccessfully on English canals, but that, no doubt, has been owing to their peculiar local circumstances. The wire rope system has been tried on the Bridgwater Canal and found unworkable owing to the large number of bends and turns and the difficulty of working the traffic in different directions. The chain system of haulage was tried on the Grand Junction Canal of Ireland as far back as 1860, but it was soon abandoned as impracticable, and steam power was substituted.