Lock canal

“ If in 1681 a French engineer had the ability and the daring to conceive and construct an octuple lock, will any one maintain that more than two hundred years later, with all the enormous advance in engineering, with a better knowledge of hydraulics and a more perfect method of transportation and handling of materials—will any one maintain that we are not to-day competent to construct successfully a lock canal such as is proposed to be built at Panama upon the judgment of American engineers? ”

“ The obstruction in the channel would be no real injury to the canal at all: it would necessitate merely a few days work at the most for its removal. An injury to the locks, however, might readily mean draining of the summit lake and the destruction of all between it and the sea not to speak of the indefinite period required for reconstruction. The point is that it is practically impossible for man to seriously injure a sea-level canal; it is easily possible for him to so injure a lock canal. ”

“ General Abbot, as a member of the consulting board, had signed the report of the minority in favor of a lock canal. Gen. George W. Davis, United States Army, for a time governor of the Canal Zone and president of the International Board of Consulting Engineers, restated his views and convictions as opposed to the lock-canal type and in favor of the sea-level project. ”

“ The majority of the committee attack the proposition that the proposed lock canal will have "locks with dimensions far exceeding any that have ever been made." If this principle were adopted in every other line of human effort all advancement would come to an end—even the canal enterprise itself—for, as it stands to-day, it far exceeds in magnitude any corresponding effort ever made by this or any other nation. ”

“ I believe the lock canal affords quicker construction, that the wider and deeper waterways it provides would give better navigation; that the transit of ships would be quicker and that the lock canal would have even a greater capacity for traffic than the narrow waterway proposed by the sea-level canal committee. ”

“ If they do become greater the Panama Canal will be an inefficient servant and will come far short of fulfilling the purpose which prompted its building. The sea-level canal could be enlarged by dredges without stopping traffic through it,18 but with a lock canal it is different. When the locks as constructed become inadequate the only way to increase their capacity is to shut down the canal for years while new and larger ones are being built. ”

“ They advance a number of specific reasons why a lock canal when completed will for all practical purposes—commercial, military, and naval—be a better canal than a sea-level waterway with a tidal lock, as proposed by the majority members of the Board. ”

“ But in 1880, when the canal had been transferred by the State of Michigan to the United States, as a work of national importance, the Government undertook the construction of a new lock, which was opened in 1881, and which has been described by competent engineers as the finest piece of hydraulic engineering on the American continent. The lock is at the lower end, and is 515 feet long between the gates and 80 feet wide in the chamber, with 17 feet of water on the sills. The lift is 18 feet, more or less, according to the fall in the rapids between Lake Superior and Lake Huron. ”

“ Passing through a lock in a small boat, and in company with a canal-boat, is not a perfectly safe thing to do; for if the ropes which fasten the canal-boat should break—which they sometimes do—the water rushing in through the sluices would force the canal-boat against the lower gate, and crush the small boat like an egg-shell. It is therefore best always to pass through a lock alone, or in company with other small boats. The danger, however, is in reality very slight, and very few accidents occur in canal locks. ”

“ Our concern is with a matter of fact, and not with a theory. No ship-owner on the Great Lakes considers it a serious hindrance to navigation for vessels to pass through the lock of the "Soo" Canal; no shipper running 1,000-ton barges through the future Erie Canal will have the least apprehension of danger or destruction; no captain navigating a vessel or boat through the proposed deep waterway from the ocean to the Lakes will hesitate to pass through locks with a proposed lift of over forty feet. ”

“ It is not necessary to dwell upon the fact that all naval commanders and commercial masters of the great national and private vessels of the world are almost to a man opposed unalterably to the introduction of any lock to lift vessels over the low summit that nature has left for us to remove.
I am not aware that any material evidence of this character has come before the Senate Committee on Isthmian Affairs, investigating conditions at Panama. I do know this, however, that until very recently it has been the American project to construct a lock canal. ”

“ The enlarged locks on the Canal du Centre can be filled or emptied in two minutes; and the passage of vessels through the locks takes less than half the original time.
Mr. E. J. Lloyd, speaking from experience of canals in the Midlands, is of opinion that a multiple of the present size of lock which prevails throughout the Midland district would be best. This would enable the existing craft on those canals, and also most of the barges on larger navigations, to be used in the most economical way possible. ”

“ The canal lock of to-day is a very slow working affair, as we all know, and is such a clumsy piece of mechanism that only ships of a limited tonnage can pass through it. When a canal-boat comes along it is let into the first lock, and if that is on the higher level the gates are closed, and the water is allowed to run out until the boat is floating on a level equal to that in the other portion of the lock. ”

“ We have seen that on the Middlesex canal, there are 22 locks for 28 miles, which is a lock for somewhat less than every mile, whereas, 62 locks for 300 miles is but about one lock for every five miles; and the lockage of the Middlesex canal, would alone cost 220,000 dollars. It would, therefore, appear to be an allowance perhaps too liberal, to consider the cost of it as a fair criterion of the expense of canals in general in this country, and of this in particular. Reservoirs and tunnels, are the most expensive part of the operation, and none will be necessary in our whole route. ”

“ With perfect arrangement the loss is very small; frequently it is, in fact, very considerable. “In the event of a heavy traffic being thrown on our canals, it will probably be advisable to double the locks, a communication being made practicable between the pair, in order to save half a lock full of water at each passage. With this arrangement much time as well as much water may be saved. The average retardation due to the hydraulic requirements alone of the locks on the English canals is from 13⁄4 to 2 minutes per mile, the average rise to be overcome being under 6 feet per mile of canal.” ”

“ There are no locks in the world where these precautions are so minute and numerous. It is all of course in the interests of the owners to inspire the maximum of confidence in maritime circles. Complete efficiency in the operation of the canal, absolute safety for the vessels and cargoes entrusted for ten or twelve hours to its keeping, are the elementary conditions of success. Each lock through which the vessel passes is equipped with two pairs of mitre gates—that is, double swinging doors—the biggest lock-gates in the world ”

“ The lock gates are constructed of greenheart timber. The sluices near the locks take the place of the weirs used in the old Mersey and Irwell navigation; they are 30 ft. span each, four being generally used at each set of locks. In ordinary seasons any water not used for lockage purposes passes over the tops of the sluices, which are kept closed; in flood times the sluices are raised to a height which will pass off floods with a comparatively small rise in the canal. There are eight hydraulic installations on the canal, each having duplicate steam-engines and boilers ”

“ The whole proposition in regard to canal revival would be changed if only the surfaces in Great Britain were the same as they are, say, between [120] Hamburg and Berlin, where in 230 miles of waterway there are only three locks. In this country there is an average of one lock for every 11⁄4 mile of navigation. The sum total of the locks on British canals is 2,377, each representing, on an average, a capitalised cost of £1,360. ”

“ Noble, who has thoroughly studied lock-canal construction, management, and navigation, who as a member of the United States Deep Waterway Commission reëxamined probably as thoroughly as any living authority into the entire subject of the mechanics and practice of lock canals—is emphatically opposed to the sea-level proposition.
When a man like Mr. ”

“ Each of these three locks has, of course, a duplicate alongside, permitting, as at Gatun, the simultaneous passage of a companion vessel, or of one passing in the opposite direction. In case of repairs to one set of locks the parallel set would maintain the waterway.
The lift of the lower lock at Milaflores is variable, depending upon the level of the tidal water in the last reach of the Canal. The extreme range of the tide at La Boca, the Pacific entrance to the Canal, is 20 feet; that is to say, low water during "spring" tides is 10 feet below the average sea-level. ”

“ On the Manchester Ship Canal and the Weaver, the culvert-openings are distributed along the side walls, but even then, with only a fall of 16 ft., great care is necessary to prevent damage to small craft during the filling of the lock.
Pumping for Locks. The only way of meeting the difficulty of a deficient water supply for the use of the lock, is by pumping. ”

“ During the years 1890 and 1891 the United States caused to be constructed a lock at the head of the rapids in the dam which the local authorities had maintained, and constructed from that lock down the river, under the bridge and through the rapids, an artificial canal outside of the main channel of the river, and raised the locks and dam on the river below, thus providing a new means of navigation at that point. ”

“ A lock is always strongly built, of masonry or concrete. The walls have to withstand the earth pressure when the lock is laid dry for repairs. The floor has to withstand the scouring action from the 97 sluices. Regarding the upward pressure of the water when the lock is empty, see Chap. X., Art. 3. The lift or difference in the water-levels of the two reaches of a barge canal is generally from 4 to 9 feet, but occasionally it is much more. ”

“ Mr. Williams’s proposal was to construct a canal 22 feet deep and 100 feet wide, with three locks. The channel through the estuary was to be confined between training walls from Garston to Runcorn, and from there the channel was to be improved and straightened to Latchford (first lock) , and be practically a tideway. Between Latchford and Manchester it was to be a canal with locks, the existing navigation to be improved and utilised where practicable, otherwise to be filled up; while docks were to be made at Latchford, Irlam, and Barton. ”

“ The lift system thereby differing from the lock system also requires the attention of skilled men, entailing extra expense. Whilst it may be said that locks are wasteful of water, and that this waste must be made up by pumping, there is this advantage over a mechanical arrangement, that in times of large rainfall no cost is incurred in supply. ”

“ TONNAGE RATES. The last-mentioned rates are to be collected by the Birmingham and Liverpool Junction Canal Company, at the expense of the Staffordshire and Worcestershire Canal Proprietors; and in order that no unnecessary waste of water may be made, the Birmingham and Liverpool Junction Canal Company are required to construct on the sumit level, a regulation lock, consisting of four pairs of gates. The locks upon this navigation are 7 feet 6 inches in width, and 80 feet long. ”

“ The dimensions proposed for the canal are:
I should recommend double locks; but the estimates that follow suppose each lock subdivided by gates affording respectively 130, 218, and 320 feet of lockage length.
It is extremely difficult, nay, impossible, to determine the amount of water required to feed a canal, unless the condition and nature of its trade are known. This is especially the case when the transit has to be effected through an undeveloped country, under very anomalous political, social, industrial, and economical conditions. ”

“ In passing a ship through the canal it will be necessary to open and close 23 lock gates, of an aggregate weight of more than 25,000 tons, to lower and raise 12 fender chains, each weighing 24,000 pounds, and to shut and open dozens of great valves, each of which weighs tons. All these operations at each set of locks will be controlled by one man, at a central switchboard. ”

“ The force required at the locks will be comparatively small. It will consist of men in general charge of the lock operations, men in charge of the towing operations, men who handle the various mechanism and operate the several types of valves for the regulation of the water in the locks; and the general labor force consisting of a few hundred operatives at each end of the canal. A force will be required to operate the big hydro-electric station at Gatun Spillway, where the electricity for the operation of the locks and for the lighting of the canal will be generated. ”