Obrázky stránek
PDF
ePub
[graphic]

LIFT SILL AND FOREBAY, LOOKING SOUTH, FROM WEST WALL, GATUN LOCKS, FEB. 1, 1910.

[blocks in formation]

the American people looked for a waterway that would accommodate the largest ships that might reasonably be expected to be built for some time to come. The Commission had much greater scope than the French company in making its plans. The latter was bound to keep the cost within the limits of commercial feasibility. The former, while of course always considering economy, and aiming, if possible, to make the enterprise a paying one, has proceeded on the principle that the first and most important requirement is a commodious and permanent canal, no matter what the cost. In pursuit of this object, numerous improvements and additions have been made to the plan from time to time, with the result that the finished structure will very greatly exceed in cost the original estimates for it.

The question of whether the canal should be one with a number of locks or one at sea level caused as much discussion and partisanship as that of the route. It was not finally decided until the middle of 1908, when the construction passed into the final stage from which there could be no turning back.

The Walker Commission favored a plan for a multi-lock canal with eighty-five-foot summit level and a lake about thirty-eight square miles in area extending from Bohio to Bas Obispo. This was practically the project recommended by the Comité Technique and, although it was not adopted, it formed the basis of the plan under which we are proceeding.

In rejecting the sea level alternative, the Commission made the following statement:“ If a sea level canal be constructed, either the canal itself must be made of such dimensions that maximum floods, modified to some extent by a reservoir in the Upper Chagres, could pass down its channel without injury, or independent channels must be provided to carry off these floods. As the canal lies in the lowest part of the valley, the construction of such channels would be a matter of serious difficulty, and the simpler solution would be to'make the canal prism large enough to take the full discharge. This would have the advantage, also, of furnishing a very large canal, in which navigation under ordinary circumstances would be exceptionally easy. It would involve a cross section from Obispo to the Atlantic, having an area of at least 15,000 square feet below the water line, which would give a bottom width of at least 400 feet. The quantity of excavation required for

« PředchozíPokračovat »