at the same time as Goethals, and he was put in charge of the central district of the canal, which was responsible for all of the work between Gatun Lake and the Pedro Miguel locks—most notably, the Culebra Cut. Gaillard brought dedication and quiet, clear-sighted leadership to his difficult, complex task. The scale of the work was massive. Elaborate (multiple) air compressor facilities using some 30 miles of pipe powered hundreds of compressed air drills to bore holes for 400,000 pounds of dynamite per month to blast and fragment the rock of the cut so that it could be excavated by steam shovels, most made by Bucyrus Foundry and Manufacturing Company of Milwaukee. Dozens of spoils trains took the spoil from the shovels to the landfill dumps, about away. In a typical day, 160 trainloads of material were hauled away from a cut . This workload on the railroads required some skillful co-ordination. At the busiest times, there was a train going inbound or outbound almost every minute. Six thousand men worked in the cut, drilling holes, placing explosives, controlling steam shovels, and running the dirt trains. They also moved and extended the railroad tracks as the work moved forward. Twice a day work stopped for blasting, and then the steam shovels were moved in to take the loose spoil (dirt and rock) away. More than 600 holes filled with dynamite were fired daily. In all, of dynamite were used. In some locations, about of dynamite were planted and detonated for a single blast. Landslides The excavation of the cut was one of the greatest areas of uncertainty in the creation of the canal, due to the unpredicted large landslides. The International Board of Consulting Engineers had mistakenly decided that the rock would be stable at a height of with a slope of 1 in 1.5; in practice, the rock began to collapse from that slope at a height of only . The misjudgment was in part due to unforeseen oxidation of the underlying iron strata due to water infiltration, which caused weakening and eventually a collapse of the strata. Strain softening of the underlying shale layers of sedimentary units caused continuation of sliding as the strength of the slide post-failure was reduced. The first and largest major slide occurred in 1907 at Cucaracha. The initial crack was first noted on October 4, 1907, followed by the mass wasting of