64 REPORT OF BOARD OF CONSULTING ENGINEERS, PANAMA CANAL.


considered. The maintenance and operation of locks is also costly. If of such great dimensions as those considered necessary by the Board under the Spooner Act, they require the installation, maintenance, and operation of an extensive power plant for the working of the gates. It is not easy to estimate what the annual cost of maintenance, including renewals and operation, of these would be, but, using the estimates of the Isthmian Canal Commission of 1899-1901, it is probable that the annual cost of operation of the six locks contemplated in the projects brought before the Board would be about $525,000. This annual charge capitalized at three per cent would make a sum of $17,500,000 to be added to the cost of the lock canal. The corresponding item in the sea-level plan would be the capitalized annual cost of operating the tidal locks near Panama.
 The comparative ease and economy of enlarging the prism of the sea-level canal to accommodate any additional demands of the future must be given the weight which properly belongs to it. The operations which have already been conducted so extensively in enlarging the prisms of the Suez and Manchester Ship canals, and which are now about to be undertaken at the Kaiser Wilhelm Canal at Kiel, show that such operations may be required. The facility with which work of that character may be done in a sea-level waterway where there are no lock structures constitutes a material advantage.
 It has already been stated as the opinion of the Board that the time required for the construction of the Panama Canal with a summit level at 60 feet above mean sea level will at best be only two years less than required for the construction of the sea-level canal. But as affecting this question of time, it should be observed that accidents during construction leading to an extension of the time required to complete the canal would be more likely to occur in the more numerous structures involved in the building of the lock canal than in the works for the sealevel canal. It has f urther been shown that the difference in cost between the two plans will not exceed about $71,000,000 in favor of the former, which must be reduced by the capitalized cost of the maintenance and operation of locks and by the cost of the overflowed lands, as before stated.
 It is seen, therefore, that the lock design has inconsiderable advantage either in time of realization or ultimate cost over the one recommended by the Board for adoption by the United States Government, which possesses all the advantages of practically indefinite capacity for traffic, besides a degree of safety and uninterrupted operation which can not be approached by any lock plan.
 Did a canal now exist of the widths proposed, but limited in depth to 35 feet, it would accommodate all existing shipping. By restricting the depths in the prisms (but not in the locks), as suggested but not recommended, the channel could probably be opened in a year or two less than if constructed at first to full depth, and the saving in cost would amount to about $17,000,000. When it should be decided to take out the other five feet in order to accommodate vessels of a greater depth, that could readily be done at some increase of cost over what would have been incurred if made originally at the fll depth of 40 feet.
 The Board desires to emphasize the fact that in its knowledge no great enterprise in connection with transportation, whether it be a canal, a railway, a harbor or docks, or similar work, has ever Yet been completed of such size or proportions that subsequent enlargement did not become necessary. The Board is therefore of the opinion that in this particular case the United States Government should construct this great artificial waterway of such type and dimensions as to give it at the outset the maximum capacity that seems likely to be required, guaranteeing the greatest facility of operation, and leaving the canal as constructed with ample provision for a reasonable future increase of traffic and in condition for most speedy and economical enlargement in response to the future demands of commerce, without the undoing of any construction.
 It is the belief of the Board that the essential and the indispensable features of a convenient and safe ship canal at the American Isthmus are now known; that such a canal can be constructed in twelve or thirteen years' time; that the cost will be less than $250,000,000; that it will endure for all time.


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