 |
| The Culebra Cut - Under construction 1907 |
One of the greatest barriers to a canal was the continental divide, which originally rose to 110 metres (360.9 ft) above sea level at its highest point; the effort to create a cut through this barrier of rock was clearly one of the greatest challenges faced by the project, and indeed gave rise to one of the greatest engineering feats of its time.
When Goethals arrived at the canal he had brought with him Major David du Bose Gaillard, of the U.S. Army Corps of Engineers. Gaillard was placed in charge of the central district of the canal, which stretched from Pedro Miguel Locks to the Gatun Dam, and dedicated himself to the job of getting the Culebra Cut, as it was then known, excavated.
The scale of the work was massive: six thousand men worked in the cut, drilling holes in which were placed a total of 27,000 t (60,000,000 lb) of dynamite to break up the rock, which was then taken away by as many as 160 trains in a day. Landslides were a frequent and major problem, due to the oxidation and weakening of the underlying iron strata in the rock. The scale of the job, and the frequent unpredictable slides, tended towards chaos; but Gaillard overcame the difficulties with quiet, clear-sighted leadership.
On May 20, 1913, Bucyrus steam shovels made a passage through the Culebra Cut at the level of the canal bottom. The French effort had reduced the summit to 59 metres (193.6 ft), but over a relatively narrow width; the Americans had lowered this to 12 metres (39.4 ft) above sea level, over a much greater width, and had excavated over 76,000,000 m3 (99,000,000 cu yd) of material. Some 23,000,000 m3 (30,000,000 cu yd) of this material was additional to the planned excavation, having been brought into the cut by the landslides.
Dry excavation ended on September 10, 1913; a slide in January had brought1,500,000 m3 (2,000,000 cu yd) of earth into the cut, but it was decided that this loose material would be removed by dredging once the cut was flooded.
No comments:
Post a Comment