AT WORK IN THE CULEBRA CUT.
The plan of the canal contemplated that this dam should be surmounted by three locks constructed in pairs, so that in case one series of locks became impaired the other could be used, or ships might pass up one side and down the other at the same time. Each of the locks was to be 1000 feet long, 110 feet wide, and have a lifting capacity of 28½ feet. Therefore, when completed, this series of locks constructed of concrete would be more than 3000 feet in length and about 250 feet in width, without doubt the largest concrete formation ever constructed.
The engineers of the Panama Commission give four reasons for the adoption of the lock system instead of the sea-level type. In the first place, it would take twice as long to construct a sea-level canal as it would a lock canal. Secondly, it would cost twice as much money, and as the lock canal system is costing nearly four hundred millions of dollars, the difference in cost would be a great obstacle to the construction to the other type of canal. The third reason was that in case a sea-level canal was constructed it would be necessary to place locks somewhere along its course because of the fact of the variation of tides between the Atlantic and the Pacific Oceans.
The tide rises and falls at Colon, on the Atlantic side, about 3½ feet, at the time of extreme high tide; while on the Pacific side the tides rise and fall 27½ feet, and this great variation would cause a current to rush through the course of the canal so great that locks would be required for its control.
But the fourth was the most potent reason of all why the lock system was adopted. On the Isthmus of Panama the rainfall amounts to 130 to 150 inches annually. Sometimes the precipitation will amount to 10 or 12 inches in twenty-four hours. The Chagres river is the only agency for the drainage of a vast area of water-shed in the Caribbean sea. Therefore, at times the Chagres river might be a small, inconsequential stream that a boy could wade across, and yet before twenty-four hours had elapsed, because of a heavy rainfall, it might have swelled into a raging torrent that would wreck the strongest battleship of the American navy. The large volume of water discharged by the Chagres river could not be turned into the canal proper, as the currents and the rush of flood waters would soon impair the banks of the canal.
The Lock System Adopted
Therefore it would be necessary, under the sea-level type of canal, to construct a series of embankments and dams that would be far more expensive to build and keep in repair than would be one great dam over the course of the Chagres river. Besides, the safety of the lock system would be much greater than that of the sea-level type. These were the reasons which finally controlled the determination of the engineers to construct a lock system of canal.
After the type of canal was decided upon, the next step was the assemblage of the force of laborers and the mechanical appliances necessary for the physical operations. In order to carry out this scheme, a commission was originally appointed, composed half of civilians and half of military officers. The first engineers were selected as being the most eminent of their profession, and taken from civil employment.
But great difficulties were encountered in perfecting the proper kind of an organization to successfully complete this stupendous project. The engineers taken from private life and entrusted with the work, after a little experience on the Isthmus, would be offered greater inducements to abandon their Governmental employment and take some other position, generally far more lucrative, in the United States. And so, either through accident or design, the Canal Commission lost the services of such men as Wallace, Stevens, Shonts, Grunsky, and other noted engineers, and again it seemed as if canal operations would be badly crippled for want of the right kind of men to direct the work.