The Panama Canal: A history and description of the enterprise

by J. Saxon Mills

THE CULEBRA CUT.

The most famous section of work on the canal has been that at the vertebra or "continental divide," which runs along the isthmus on the Pacific side and had to be pierced through by any canal running from Colon to Panama. This tremendous work, known as the "Culebra Cut," from the name of one of the hills, extends for nine miles from Bas Obispo to Pedro Miguel. Mr. Bryce has truly said, referring to this section, that "never before on our planet have so much labour, so much scientific knowledge, and so much executive skill been concentrated on a work designed to bring the nations nearer to one another and serve the interests of all mankind."[16] The bottom of the canal in the cut, as in the channel through Lake Gatun, is 40 feet above sea-level. The highest elevation of the original surface of the ground above the centre line of the canal was 312 feet above sea-level, so that the total excavation along this saddle was 312 minus 40, or 272 feet. This was, however, not actually the highest point of excavation. Gold Hill, close to the canal line, is 534 feet above sea-level, and from the top of this hill a new and steeper slope had to be made. The surface of the water is 85 feet above sea-level, and so is 227 feet below the original saddle at its highest elevation. We have already noticed that a tide-level canal would have involved an excavation 85 feet deeper, and the width of the cutting would have had to be immensely wider. The slides and breaks which have rendered the American excavation so much more difficult lead one to suppose that the tide-level cutting might have proved impracticable.

All the work at Culebra performed by the French was available for their successors. The French companies accounted for 18,646,000 cubic yards of material on this section. They had already cut down 152 feet below the original surface at its highest elevation, and the cliff they had cut in the face of Gold Hill was 374 feet in vertical height. It is well to mention such figures, as some people imagine that the French wasted all their time and resources at Panama. It may be added that the bottom width of the channel adopted by the French engineers was 74 feet, whereas that of the American canal will be 300 feet.

Many descriptions have been given by visitors of the spectacle presented in this long and deep gash through the mountains during the progress of the excavations. From these and the numerous photographs taken at that stage the traveller will be able to reconstruct the scene—the two hundred miles of railroad construction track, laid down tier above tier at different levels; the thousands of men busily at work; the roar and smoke of the dynamite tearing the rock into fragments; the mighty steam-shovels like great dragons burying their iron teeth in the surface of the bank, engulfing a huge mouthful, then swinging round and belching it all into the dirt trucks, to be carried off to the dumping-ground at Gatun near the Atlantic or Balboa at the Pacific end of the canal. At Culebra, Colonel Goethals made the "dirt fly" to the full satisfaction of public opinion in the United States. All sorts of devices and machinery were employed to hasten and economize the process. For example, there was the Ledgerwood Unloader. Railway trucks provided with flaps were used, these flaps making a single platform of the whole train. At the rear of the train was a plough which could be drawn by a wire rope attached to a drum carried on a special car in the fore part of the train. When the train arrived at the dumping-ground the drum was started, and the plough, advancing from the rear, swept the 320 cubic yards and rock from the sixteen cars in seven minutes. Then there was a "track-shifter," invented by an employee on the isthmus, which lifted and relaid the railway lines as the spoil-tracks had to be shifted. This powerful engine raised the track and ties clear of the ground and deposited them from three to nine feet sideways.

The "spoil trains" were treated with all the respect which is accorded to the fastest mail trains of the day on an English main line. They followed one another from the cutting at intervals of three minutes, and any delay, of course, balked the mammoth steam-shovel of its gluttonous meal on the stones and rubble of the mountain-side. Any cause of delay was at once reported by telephone to the superintendent of transportation at Empire, and the obstruction was immediately dealt with. By this persistent concentration on the main object the dirt has been made to fly not only more speedily but more cheaply.

One of the most serious causes of anxiety and difficulty along the canal line were the "slides" and "breaks" which kept occurring in the Culebra Cut. To use a condensed Americanism, the sides would not "stay put." Large masses of material would slide or move from the banks into the excavated area, closing off the drainage, upsetting the steam-shovels, and tearing up the tracks. A very unpleasant phenomenon was the lifting of the shovels in the bottom of the canal due to the bulgings of the earth there. It is not necessary to enter into the distinction between "slides" and "breaks," or into the learned disquisitions that have been written about them. It is sufficient for us to note that they added immensely to the amount of material which had to be got out of the Culebra gorge. Colonel Goethals tells us that of the 14,325,876 cubic yards removed during the year 1909, 884,530 cubic yards, or 6 per cent., were due to slides; that in 1910 of 14,921,750 cubic yards removed, 2,649,000, or 18 per cent., came from slides or breaks that had previously existed or that had developed during the year.

It might have been imagined that these discouraging additions to the work would have seriously delayed progress on the canal and put forward the date of its completion. But able and economic organization triumphed over all these lets and hindrances. At the beginning of the American excavations the engineers estimated that 103 million cubic yards of "dirt" had still to be removed, and that this work would take nine years to accomplish. But that estimate of material proved to be greatly below the mark. Enlargements of the canal and the unforeseen collapses in the Culebra Cut brought up the total to 195 million cubic yards. It is a remarkable evidence of the efficiency and economy of the American organization that this immense task will have been completed in about six years of actual full-swing work.

Some idea of the way in which Colonel Goethals made the dirt fly may be gathered from the fact that in the first five years of his directorship, down to April 1912, he removed 160 million cubic yards of material. "If all this material," writes Mr. Showalter, "could be placed in a solid shaft of the shape of the Washington Monument, with a base as large as an average city block, it would tower more than six miles skyward, overtopping the earth's loftiest mountain peak by more than a mile. Again, if it were to be loaded on to the big Lidgerwood dirt cars used on the canal, it would make a string of them reaching over two and a half times around the earth, and requiring a string of engines reaching from New York to Sac Francisco to move them." It is indeed a remarkable achievement that, while the amount of material to be removed was increased by about 90 per cent., the time of removal was cut down by 30 per cent. Nor has the increase of the work added to the estimate of cost. The total cost of the completed canal was fixed in 1908 at 375 million dollars. Yet, in spite of the increased excavations, enough of this sum, it is calculated, will be left over to build a new breakwater, and perhaps a big storage reservoir at Alhajuela on the upper reaches of the Chagres River. In the Culebra Cut, despite the landslides, the cost of excavation has actually been reduced by more than one-third.