Now stretches a man-made canyon across the backbone of the continent; now lies a channel for ships through the barrier; now is found what Columbus sought in vain—the gate through the west to the east. Men call it Culebra Cut.
Nine miles long, its average depth is 120 feet. At places its sides tower nearly 500 feet above its channel bottom, which is nowhere narrower than 300 feet.
It is the greatest single trophy of the triumph of man over the terrestrial arrangement of his world. Compared to it, the scooping out of the sand levels of Suez seems but child's play—the tunnels of Hoosac and Simplon but the sport of boys. It is majestic. It is awful. It is the Canal.
When estimates for digging the canal were made, it was calculated that 53,000,000 cubic yards of material would have to be removed from the cut, and that under the most favorable conditions it would require eight and a half years to complete the work. But at that time no one had the remotest idea of the actual difficulties that would beset the canal builders; no one dreamed of the avalanches of material that would slide into the cut.
One can in no way get a better idea of the meaning of the slides and breaks in Culebra Cut than to refer to the accompanying figure. There it will be seen that whereas it was originally planned that the top width of the cut at one point should be 670 feet, it has grown wider, because of slides and breaks, to as much as 1,800 feet at one place. In all, some 25,000,000 cubic yards of material which should have remained outside the canal prism slipped into it and had to be removed by the steam shovels.
THE EFFECT OF SLIDES
No less than 26 slides and breaks were encountered in the construction of Culebra Cut, their total area being 225 acres. The largest covered 75, and another 47 acres. When the slides, which were more like earthen glaciers than avalanches, began to flow into the big ditch, sometimes steam shovels were buried, sometimes railroad tracks were caught beneath the débris, and sometimes even the bottom of the cut itself began to bulge and disarrange the entire transportation system, at the same time interfering with the compressed air and water supplies. But with all these trials and tribulations, the army that was trying to conquer the eternal hills that had refused passage to the ships of the world for so many centuries, kept up its courage and renewed its attack. The result is that ships sail through Culebra and that engineers everywhere have new records of efficiency to inspire them.
These efficiency records are told in the cost-keeping reports based upon one of the most careful and thorough cost-accounting systems ever devised. This system was instituted for the purpose of keeping a check upon all expenditures by reducing everything to a unit basis and then comparing the cost of doing the same thing at different places. For instance, if it were found that it cost more to excavate a cubic yard of material at one place than at another, under identical conditions, this fact was brought to the attention of the men responsible and an intimation given that there seemed to be room for taking up a little lost motion. The lost motion usually was recovered or else someone had to be satisfied that conditions were not identical after all.