« PředchozíPokračovat »
LUIS F. ESTENOZ, Comerciante en General y Constructor.
AVENIDA PAEZ No. 53, COLON, R. P.
LUIS F. ESTENOZ, General Merchant and Constructor No. 53, AVENUE PAEZ, COLON, R. P.
ber, 1907, favored locks of the latter width. The gates are to be in duplicate and of the miter type, except that the rolling gate similar to that now in use on the Ohio River will be substituted for the duplicate set at the lower end of each summit-level lock. In addition there will be provided an auxiliary pair of gates at the lower end of each flight for use as coffer dams in case it may be necessary to pump out the locks, and it has been determined tentatively to adopt a swing-bridge type of dam for emergency
GATUN LOCK SITE.-There has been a considerable division of opinion with reference to the suitability of the Gatun lock site. Former Chief Engineer Wallace went on record as opposed to dam and locks at this point on account of what he claimed to be lack of proper foundation. To actually develop the character of the foundations on which the locks are to rest five test pits, each six feet by eight, were sunk early in 1907 to the depths of the lock walls at Gatun, and one at the Gatun dam spillway. On their completion Engineers Alfred Noble, Frederick P. Stearns and John R. Freeman made a personal examination of material taken therefrom, and under date of May 2, 1907, reported as follows:
We beg to record that we found that all of the locks of the dimensions now proposed will rest upon rock of such a character that should furnish a safe and stable foundation.
Since that time careful borings have been continued over the entire area in order to secure a contoured plat of the rock surface with a view to the most economical adjustment of the locks to the site. Soft sandstones of a dirty greenish-gray color, derived from igneous rocks with a calcareous and clayey cement, are the most abundant rocks of the Gatun formation. The rocks are all well consolidated, though in a few rare cases sandy layers found which crumble on exposure to the air. These the beds that have been referred to frequently as indurated clays.” The term is a misleading since true clays make up but a small part of the formation. The beds are all “rock”, though in some instances soft enough to be loosened with a pick. It is evident that at one time this section was entirely under water, as sea shells have been picked up on top of some of the hills. Recently a steam shovel dipper dug up at Gatun an ancient bomb at a depth of fourteen feet below the surface of the ground. How it came there is a mystery. An extensive erecting plant, cable ways, etc. will be installed at this point, for the carrying and conversion of material required for use in the locks and dam.
GATUN LAKE.-As soon as the portions of the dam abutting Spillway Hill are high enough to stand 50 to 55 feet of water in the lake, it is proposed to build across the channel through Spillway Hill, a concrete dam high enough to hold the lake at the aforementioned level. During the dry season following, the dam across the channel through Spillway Hill will be brought to its full height, and a permanent spillway constructed, including the necessary regulating works by means of which the surplus water of the lake will be passed down to the sea. It is probable the lake will not be allowed to fill to the height of 50 to 55 feet until the upper end of the Gatun locks has been erected, and the upper gates built. The area of the lake will be 164.23 square miles. Its cubical capacity is not yet know!!. The lake will extend all the way from Gatun to Bas Obispo, and the towns of Lion Hill, Frijoles, Tabernilla, San Pablo, Gorgona, and Matachin will be on islands entirely surrounded ly water. Between Gatun and Bas Obispo, the Chagres River crosses the center line of the car no less than 23 times.
OVER THE DIVIDE.-The Chagres will enter the lake near Bas Obispo, and at this point the canal begins to cross the divide, by way of Culebra cut, and thence to Pedro Miguel near where the low level is again reached, : distance of about ten miles. During the past year the work of excavation in the Cut has been progressing satisfactorily. The August, 1907 excavation from the canal prism made such an excellent showing as to call forth the following congratulatory cable from the President:
Oyster Bay, N. Y.,
Sept. 5, 1907.
I heartily congratulate you and all the men on the canal
The record for the month of August was 1,274,284 cubic yards, the highest up to that time since the canal has been in American hands, and this despite a rainfall of 11.89 inches during the month.
As the work of excavation proceeds in the heavy cuttings of the Culebra Division, the question of drainage becomes more and more important. At the north end of the Culebra Division, where the Chagres crosses the line of the canal, the elevation of the water surface of the river at dead low water is about plus 44, and during the rainy season under normal conditions about plus 49 to plus 50
2525252525250R. M. S. P. Co.ox
Head Office, 18 Moorgate Street, London, E, C.
R. M, S.
To the West Indies, New York, Europe, Brazil, Uruguay, Argentina, Cuba,
Mexico, Central America, Spain, Portugal, France, Egypt, the Mediter
ranean, Australia, China and Japan.
RA, TRINIDAD, BARBADOS, CAERBOURG AND SOUTHAMPTON.
052525252520'R, M. S. P. Co.es
but durirg the great flood of December, 1906, the water surface there reached a height of plus 79.9. “It is there-. fore evident," states the report of the Commission for 1907, " that when the canal is approaching completion, a barrier or dam must be placed at the northern end of the Culebra Division, near the river, to keep out the waters of the Chagres, and that the larger part of the drainage of the canal must be carried to the south, where toward the Pacific, the land slopes more rapidly. It will however, be necessary to install centrifugal pumps in order to dispose of the water which will come down into the cut and cannot be conveniently carried off by natural drainage to the south. It is very important to divert from the canal, for construction purposes as well as for economy in maintenance after the canal has been completed, all possible water which would get into it from the adjacent watershed. is therefore proposed, during the next fiscal year, to repair and put in operation the old French diversion channel ex