Semicircular canal

“ All of the evidence, all of the supplementary expert testimony which may be obtained upon the merits of the two propositions, will not change the position of those who rest their conclusions upon American experience and upon the judgment of American engineers, and who favor a lock canal. While there is no doubt that such a canal can be constructed and can be made a practicable waterway, there is a very serious question whether a sea-level canal can be constructed and made a safe and practicable waterway, at least within the limits of the estimated amount of cost and within the estimated time. ”

“ Engineers of the highest standing at home and abroad have expressed themselves for or against one type or the other, but it is a question upon which no complete agreement is possible. In theory a sea-level canal has unquestionable advantages, but, practically, the elements of cost and time necessary for the construction preclude to-day, as they did in 1894, when the New Canal Company recommenced active operations, the building of a sea-level canal. ”

“ The shortest runs from the Mersey via the Bridgewater, Rochdale, Aston, Huddersfield, Sir John Eamsden's, and the Calder and Hebble, to the Aire and Calder Canal. The control of this through-route system between the Mersey and the Humber, excluding navigation authorities, is in the hands of no less than eight different companies; and a consignment of goods has to traverse ten distinct waterways—the gauges of locks on which range through various grades from 50 feet by 14 feet by 412 feet on Sir John Kamsden's canal to 212 feet by 22 feet by 912 feet on the Aire and Calder. ”

“ Lloyd thinks that the heavy cost involved in constructing canals of sufficient size to pass craft suitable for coasting and short continental voyages would be fatal to cheap conveyance.
The largest locks hitherto constructed are those on the St. Mary’s Falls Canal, in the United States, and the Welland Canal in Canada. On the former canal the lock opened in 1851 is 515 feet in length and 80 feet wide. The great tidal lock at Eastham, on the Manchester Ship Canal, will be 600 feet long and 80 feet wide. ”

“ The next improvement was the [Pg 144] substitution of a railway for “The Ship of the Desert,” in 1858, and the transmission of the English mails to Brindisi instead of Marseilles, and finally, the construction of the Suez Canal by Ferdinand Lesseps, the French engineer, at a cost of sixty million dollars. The canal is ninety-nine miles long with a width of 327 feet for 77 miles and 196 feet for the remaining 22 miles; the depth was originally twenty-six feet throughout, but the canal is undergoing progressive enlargement and deepening. ”

“ Although at first sight it may appear to be a work of supererogation, to carry the Canal over that part of the Isthmus which is traversed by navigable rivers, it is by many engineers considered preferable in forming a Canal, to use the rivers in its vicinity only for the purpose of supplying the Canal with water, and not as a continuation of the inland navigation, on account of the variation in the depth of rivers from floods, or other accidents. ”

“ The navigable channel from the open sea to the canal entrance could only be maintained in an efficient state by means of continual dredging, owing to the silt. The channel passed close to the lighthouse at the end of the Mole, and then in a fairly direct line, for a distance of three-quarters of a mile, to a position midway between the extremities of the two piers marking the canal entrance. Thence the deep water channel passed slightly to the westward of the central line between the piers. ”

“ It is true that no canal has been carried, like the Callao, Lima, and Oroya railroad, in Peru, to the height of nearly sixteen thousand feet above the level of the sea. [24] It has, however, on the Languedoc and other canals been found easily feasible to carry a canal to a height of 600 to 1000 ft. above the sea. Canal engineers have not, perhaps, pierced the Alps with a tunnel ten miles in length, as on the Saint-Gothard Railway; but they have carried a tide-water canal from the Mediterranean to the Red Sea, and they have essayed to perform the same feat through the Cordillera. ”

“ If it is an advantage to gain an hour or two in transit ten years hence by having no transisthmian shipping facilities for the ten years in the meantime, then it might as well be argued that it would be better to project a sea-level canal 300 feet wide at every point, so that the commerce of the year 2000 may be properly provided for. ”

“ Then again, the speed on British canals can seldom be carried above 21⁄2 miles per hour, not to speak of the delay in getting through the locks, of which there are ninety-three between Leeds and Liverpool.
It would be the idlest of idle dreams to expect that the canal system of this or any other country, as originally constructed, can be resuscitated, or even temporarily galvanised into activity, in competition with railways. Canals as they were built a century ago have no longer any function to fulfil that is worthy of serious consideration. ”

“ The innovation might be of particular importance where a new canal system is being constructed, since the latter might be subdivided into main canals and branch canals—similarly as in the case of ordinary and narrow gauge railways—the main canal being built of a larger section and with larger locks to suit the duplex barges, while the branch canals could be planned of smaller dimensions calculated to suit the semi-barge. ”

“ Longer canals have been made both in Europe and in the United States, but no canal hitherto completed has been built of the same large dimensions, nor has any other canal cost so considerable a sum of money. It is not too much to say that no other waterway has been more important to commerce, nor has any other been attended with the same momentous and permanent political consequences. It is satisfactory to be able to add that few waterways of modern times have been so successful from a financial point of view. ”

“ If a canal can be made for fifty miles, it can be made for three hundred, provided there is no essential variance in the face of the country; the only difference will be that in the latter case, it will take more time, and consume more money.
But this opinion does not rest for its support upon mere speculation. Canals have been successfully cut through more embarrassing ground, in various parts of the United States; and even in part of the intended route from Schenectady to Rome, locks have been erected at the Little Falls, and at other places ”

“ He says that the most desirable canal is the sea-level canal of such dimensions as would afford unrestricted passage for the largest vessels afloat, with such margin for increase in size and draft as can reasonably be anticipated, making allowance for unexpected developments. No plan should be adopted that would prevent the ultimate construction of a sea-level canal at least approximately approaching to the final idea of the Straits of Panama. ”

“ General Davis shows that the proposed sea-level canal will not be dangerous, narrow or contracted, because this is not true of the Suez Canal, which is longer, narrower and shallower, and has more abrupt bends than the canal proposed by the majority of the engineers. He calls attention to the fact that in the opinion of very able engineers the cost in time will be but slightly more for the channel at ocean level, than for a canal with a summit level at 85 feet ”

“ The canal has a depth of 6 feet throughout. For about 60 miles it is 60 feet wide at the top, and 42 feet at the bottom; for 47 miles its surface width is 850 feet, and its bottom width, 32 feet; and for 771⁄2 miles more the surface width is 54 feet, and the bottom width 38 feet. The locks are 100 feet long and 15 feet wide in the clear; they are capable of passing boats carrying 120 tons. There are 74 lift-locks and a tide-lock. The water-supply is drawn entirely from the Potomac, seven dams having been constructed across the river for this purpose. ”

“ Canal engineers have found that where they can concentrate the rise of level on a canal by the use of lifts, or inclined planes, they can usually obtain a considerable increase of speed. Thus, on the river Weaver, a height of 51 feet is cleared by the Anderton lift in about eight minutes. On the incline of the Morris Canal, again, a height of 51 feet is overcome in three and a half minutes; while on the Forth and Clyde Canal the Blackhill incline enables a height of 96 feet to be overcome in ten minutes. ”

“ The boats that use the canal have to be dragged through and up the sluices close to the banks, by large windlasses, whereby they are brought into still water by a very tedious process. [236]
The canal is largely used for passenger traffic, but the rate of progress seldom exceeds 25 to 30 miles a day, and is often under 20. The greater part of the work has been expended in the simple labour of constructing embankments, and not, as in the case of the Panama and Suez Canals, in digging a deep channel. ”

“ In addition to the cost of carrying water was that of keeping the track clear of sand, which was drifted by the wind exactly as snow is drifted in the Northern States of America, and sometimes the working of the road was suspended for several days by the sand-drifts. The present railway follows the banks of the Maritime Canal as far as Ismailia, and thence it goes along the Fresh-Water Canal, of which I will tell you.
"The idea of a canal to connect the Mediterranean and Red Seas is by no means a modern one." ”

“ This enormous gain in efficiency, resulting from the avoidance of the slightest difference in level and from the reduction of force wasted in friction, suggested to people in early times the idea of establishing channels for water where none had previously existed, that is, of building canals. Locks, for controlling the flow and level of the water, were invented toward the end of the Middle Ages, and a considerable extent of canals had been constructed on the Continent before the Bridgewater canal, described above, was opened in England. ”

“ The Navigation Canal is essentially a harbor improvement. It enables practically unlimited industrial development and commercial interchange. It is an important link in the Intracoastal Canal system which the government is developing to provide an inland waterway from Boston, Mass. to Brownsville, Tex., and, with the dredging of a channel through Lake Pontchartrain to the Gulf, a problem which U.S. engineers have been studying for some time and an undertaking which they have found feasible, it will put the nation's second port about fifty miles closer to the sea. ”

“ The lining for the canal was molded on the river bank, where water, sand, and gravel were available for concrete making, and the forms were carried to the top of the canyon by tram and cableways. The capacity of the canal is 300 cubic feet per second, and it is now irrigating 40,000 acres. The High line Canal of the Strawberry Valley project swings around the steep slopes of the Spanish Peaks of the Wasatch Range in Utah for several miles. At one point a portion of the water is dropped in pipes to the turbines, where power is developed and distributed to several towns in the valley. ”

“ About noon on the seventh day we entered the canal which connects this arm of the gulf with the sea of the northern temperate zone. It varies in height from 400 to 600 feet, in width from 100 to 300 yards, its channel never exceeds 20 feet in depth, Ergimo explained that the length had been thought to render a tunnel unsuitable, as the ordinary method of ventilation could hardly have been made to work, and to ventilate such a tunnel through shafts sunk to so great a depth would have been almost as costly as the method actually adopted. ”

“ These outlets consist of two inclined planes of masonry, one rising from the canal with a pavement or waste weir between them; and when the cross-stream comes down like a torrent, instead of mingling with the canal, it passes straight across. But these channels would be insufficient for carrying off the whole surplus waters in time of floods. At one place, therefore, there are three sluices by which the whole canal from the Staircase to the Regulating Lock (about six miles) can be lowered a foot in an hour. The sluices were opened that we might see their effect. ”

“ Indeed, a considerable increase in length is allowable to permit the canal to be constructed without a change of level. The reason for this is that transferring a boat from one level to another by locks or the other usual means is a slow operation, and furthermore, locks are very expensive to construct compared with a similar length of the ordinary channel. The engineer carefully integrates these factors of time and cost and selects the route between the various points he wishes to connect which will give the minimum time of transit at the minimum cost. ”

“ According to the Isthmian Canal Commission, the present canal affords greater safety for ships and less danger of interruption to traffic by reason of its wider and deeper channels; it provides for quicker passage across the Isthmus for large ships and for heavy traffic; it is in much less danger of being damaged, and of delays to ships because of the flood waters of the Chagres; it can be enlarged more easily and much more cheaply than could a sea-level canal. The lock canal has a minimum depth of 41 feet, and less than 5 miles of it has a width as narrow as 300 feet. ”

“ The latter plan was in principle adopted, and the details were worked out, in 1883, by the Hungarian engineer Willandt. The longest canal will be that on the Servian bank, with a length of over two kilometers and a width of eighty meters. It will be left for a later period to make the canal wider and deeper, as was done with the Suez Canal. For the present it is considered sufficient that moderate sized steamers shall be able to pass through without hindrance, and thus facilitate the exchange of goods between the west of Europe and the east. ”