Other features of the canal include a sea-sluice, constructed below the downs, with a double bridge, one-half of which will be devoted to the Blankenberghe-Heijst Railway; the other half to general use. The bridge is 8 metres—about 26 feet—wide, and the opening at the sluice, as also at the bridge, is 20 metres (about 65 feet), thus enabling several ships to enter at a time. Another sluice-gate is fixed some 200 metres (about 7900 feet) lower, and the part of the canal between will be made quite secure by means of a flood-gate. The cost of these works amounted to about 2,000,000f. (80,000l.). The plans also provided for two bridges, one on the Lisseweghe-Dudgeele, the other on the Lisseweghe-Heijst high roads, and four syphons for the draining of the low waters of the country, to run under the canal at a depth of eight metres (about 26 feet) below the water-line.[81]
The river Rupel, which is about 12 miles above Antwerp, leads from the Scheldt to Willebrock, opposite the town of Boom. From here a canal with five large locks leads to Brussels. This canal, which had its origin in the year 1415, but which was only completed in 1561, is of considerable importance. The traffic on it is heavy, and it is worked by the Corporation of Brussels, the result usually leaving a profit. The tolls on this canal are—First class, ·06 franc; second class, ·04½ francs; third class, ·02 franc per ton. In all cases a cubic metre is reckoned as 1000 kilogrammes, or one metrical ton. In the first class is reckoned merchandise, &c.; in the second class, bricks, firewood, stone (wrought or unwrought), salt, &c.; and the third class, unladen vessels.
There is a depth of from somewhat over 10 feet of water, but this is limited to an effective depth of 3·10 metres where it passes over a small stream by a brick aqueduct. A line of steamers belonging to Messrs. Thomas & Co., of London, runs to Brussels regularly, and several Dutch lines of steam barges use this route. Sailing vessels and lighters are worked on the canal by means of the chain system, with remorqueurs, twenty to thirty being thus easily towed. The locks are large, and as many vessels pass at the same time, the trains are made up accordingly. When two meet, the ascending tug drops the chain, the train keeps on its right side, and the chain is again picked up by a grapple when the descending train has passed. With this system the vessels are easily steered by the men at the helm. When approaching a lock, the chain is thrown off in proper time, and the vessels’ way being checked, they gradually settle side by side in the lock. Great skill and care is used by the men, damage by collision rarely occurring. One great advantage attending this system of towage is that the tugs make no wash, which so much destroys the banks of canals. The tolls are light, and the rates for towage very low. Empty vessels only pay 20 c. for a laissez passer vide; this ticket, as in France, can be taken from any bureau de navigation to any other place in the kingdom or in the Republic.
Belgium has made a substantial contribution to the more important engineering features of canals by the construction of the La Louviére Canal lift on the Terneuzen Canal, which is illustrated on the opposite page.
La Louviére Canal Lift.
This canal lift was constructed for the Belgian Government by the Société Cockerill, of Seraing, from the designs and under the superintendence of Messrs. Clark, Stanfield, and Clark, of Westminster, consulting engineers to the Government, and the patentees of the system. The difference between the levels of the upper and lower canals—that is, the height the boats are raised—is 50 feet 6¼ inches. The lift consists of two pontoons, or troughs, each 141 feet long by 19 feet broad, with 8 feet draught of water, and are capable of holding the largest size of barge that navigates on the Belgian broad-gauge canal system. Such barges are capable of taking 400 tons of coal or other cargo, so that the total weight of the trough, water, and barge is not much under 1000 tons. This immense weight is supported on the top of a single colossal hydraulic ram of 6 feet 6¾ inches diameter and 63 feet 9½ inches long, working in a press of cast iron, hooped continuously, for greater security, with weldless steel coils. The working pressure in this press is about 470 lbs. to the square inch. The time actually occupied in lifting or lowering is only two and a half minutes. The La Louviére lift is said to be the largest in the world.
The Scheldt Navigation.—In the recent history of the shipping industry, the city of Antwerp has played a prominent part, thanks partly to the facilities afforded by the river Scheldt, partly to the easy means of access to other parts of Belgium and Holland by sea and canal, and partly to the very low rates charged for transport by both systems of navigation.
Up to the year 1863, the Dutch Government levied a tax upon all vessels using the Scheldt. This tax was found to be so onerous, that treaties were entered into in that year by which, in consideration of certain specific payments made by the various countries concerned in the navigation of the river, the King of Holland renounced his right to levy such duties.[82] Since then the trade of Antwerp has advanced by “leaps and bounds.” Between 1862, the year previous to the abolition of the taxes on shipping, and 1887, the importations into Antwerp had increased by 335 per cent., and the exportations from Antwerp had increased by more than 500 per cent. In the general transit trade the increase was equally striking, amounting to about 400 per cent. The tonnage of vessels entering the port of Antwerp within the same period advanced by about 600 per cent.[83]