The greatest difficulty encountered in the excavation of the canal was due to slides and breaks which caused large masses of material to slide or move into the excavated area, closing off the drainage, upsetting steam shovels and tearing up the tracks. The greatest slide was at Cucaracha, and gave trouble when the French first began cutting in 1884. Though at first confined to a length of 800 feet, the slide extended to include the entire basin south of Gold Hill, or a length of about 3,000 feet. Some idea of the magnitude of these slides can be obtained from the fact that during the fiscal year 1910 of 14,921,750 cubic yards that were removed, 2,649,000 yards, or eighteen per cent, were from slides or breaks that had previously existed or that had developed during the year.

One of the Guard Gates, Gatun Locks, Panama Canal Each lock is provided with four gates. This shows the method of construction, the gate being only partially finished..

Gatun Upper Locks, East Chamber The view is looking north from the forebay showing the upper guard gates and emergency dam.

The one greatest undertaking of the whole excavation was the Gaillard Cut. Work had been in progress on this since 1880, and during the French control over 20,000,000 cubic yards were removed. On May 4, 1904, when the United States took charge, it was estimated that there was left to excavate 150,000,000 cubic yards. Some idea of the size of this big cut may be formed from the fact that this division has within its jurisdiction over 200 miles of five-foot-gage track laid, about fifty-five miles of which is within the side slopes of the Gaillard Cut alone.