Tanada wrote:If they had made the cut wide enough to make it sea level as originally intended the slope angle would be greatly reduced which limits the tendency to shed material into the channel.
Yes I see. They were probably constrained by the necessity to dump all the spoil. I found an illuminating article on it, incredible achievement for it's day. I suppose they just wanted to get it up and running as fast as possible and see a return on the investment. Once it was completed there was no going back because that would have necessitated closing the canal for some time (lost revenue) If it had been built in the 1950's it no doubt would have gone the way you recommended.
For those interested
Culebra CutCulebra Cut was the “special wonder” of the canal. Here, men and machines labored to conquer the 8.75-mile stretch extending through the Continental Divide from Gamboa on the Chagres River at the north to Pedro Miguel on the south. The lowest point in the saddle between Gold Hill on the east and Contractors Hill on the west was at elevation 333.5 feet above sea level.
Holes were drilled, filled with explosives and detonated to loosen the rock and rock-hard clay. Steam shovels then excavated the spoil, placing it on railroad cars to be hauled to dump sites. Excavation equipment, in addition to the railroad itself, included steam shovels, unloaders, spreaders and track-shifters. Of this equipment, only the steam shovel had been known to the French, and then in a much less powerful form.
The Lidgerwood unloader, manufactured by the Lidgerwood Manufacturing Company of New York City, was another indispensable piece of equipment. Wooden flatcars with a rated canal capacity of 19 cubic yards hauled most of the spoil, pulled in long trains by full-sized, American built locomotives. Built with only one side, they had steel aprons bridging the spaces between cars. Dirt was piled high against one side. At the dump site, the unloader, a three-ton plow, was hitched to the last car by a long cable to a huge winch-like device mounted on a flatcar at the head of the train. Taking its power from the locomotive, the winch pulled the plow rapidly forward, unloading the whole twenty-car train in a single, 10-minute sweep. One of these machines once set an 8-hour record by unloading 18 trains, about 3 ½ miles of cars containing about 7,560 cubic yards of material. Engineers estimated that 20 of these unloaders operated by 120 laborers did the work of 5,666 men unloading by hand.
More than a hundred million cubic yards of spoil had to be hauled away from the excavation site and dumped. Part of this spoil was used to join a series of four small islands in Panama Bay (Naos, Perico, Culebra and Flamenco) to create a breakwater....
Spoil was also used to claim nearly 500 acres of Pacific Ocean to create the Balboa townsite and the Fort Amador military reservation. Millions of cubic yards of material also had to be hauled out to big waste dumps in the jungle. In the largest of these, Tabernilla, 17,000,000 cubic yards of material were deposited. Balboa was the biggest dumpsite. Other big dumps were Gatun Dam, and Miraflores...
https://pancanal.com/en/culebra-cut/
The 'peak oil' story is not over by any means. Fracking was a desperate and ruinous sort of pause, which has been used to crank up demand.