REPORT OF BOARD OF CONSULTING ENGINEERS, PANAMA CANAL.


cut is very largely one of transportation, and by transportation I do not mean simply hauling it, I mean disposing of it-getting rid of it. It is going to require the most perfect organization that ever was contemplated; but it is something that we have not got far enough along with yet to give the details. I regard the whole Culebra cut as a soft-rock proposition, because the great part of it has got to be shot. While it is true that a shovel would pick- up some of it without blasting, you can do it all much more economically to shoot it. Therefore, when you come to a question of how much an excavator will handle-I do not care whether it is a French machine, English machine, or a steam shovel-if you can keep the cars or the scows or whatever are serving the excavating machines, there is no limit of power of the machines, it is merely the disposal of the material. The French company fell down because they could not dispose of the material. Now we criticise their plant, but that is not fair. They loaded more than they could get rid of. That is perfectly clear to me by the casual examination I have given their excavators and the different spoil banks. They used a heavy grade and a type of car that would not dispose of the material; it had to be cleared by shoveling. At that time it was considered a modern plant. Now 1 would liken that plant to a modern one as baby carriages to automobiles. This is no reflection on the French, but I can not conceive how they did the work they did with the plant they had.
 Mr. BURR. Has the chief engineer, so far as his experience has gone, reached no approximate idea as to the slopes which it would be fair to assume to enable us to estimate the amount of excavation in the Culebra below the upper soft portion; or, to put it definitely, the lower threefourths of the depth in case a sea-level canal or a less proportionate depth in case of a lock canal?
 Mr. STEVENS. As far as I have been able to observe, you can classify the Culebra above as red clay overlying argillaceous schists, with hard igneous trap thrown up through it. A great many borings have been made. It is a mixed conglomerate mass. Sometimes at 100 feet from a boring the conditions may be entirely different.. If the material is, as some say, like that seen in the center of the big cutting, then I would consider it a waste of money to dig it out with a 1 to 1 slope. I have had a great deal of experience in handling all sorts of material, heavy and light, and the old formula used to be in such cuttings 1' to 1. Now, a great many years ago I made up my mind that I was not spending money to the best advantage. I was on the west coast, at Puget Sound, and I formed a theory that in the case of that material which I called hardpan that if I had 20,000 yards to take out of a cut, instead of taking it out with a slope of 1 on 1, why not widen my base-the cost would be the same-on the theory that in a country where there is a heavy rainfall a material that would stand with steep slopes offered so much less area for rivulets to form; and for a long time either in the soft rock or compact indurated clay I have adopted that policy. If my standard roadbed was 26 feet and I had a 40-foot cut, I probably made the cut 45 feet wide. Occasionally that would fall down; when it did I had plenty of room to remove the material. I believe that when we get back to these slopes at deeper cuttings if the material proves to be what I call homogeneous, that is it does not lie tilted or in layers, and we find a horizontal strata that would stand without question, and under that we find a strata that the air and water would gradually work on-if we find a condition of that kind there is nothing to do but make the slopes so that the soft material under the harder materials will come to a rest, but outside of that if we get hard material it is my honest opinion that it will stand just as well vertically as at any other slope.
 The CHAIRMAN. You are going to take off that red and chocolate colored material before going deeper?
 Mr. STEVENS. That top stuff will cost more to handle than any material you see in the cut. There is no excavator that will clear that, during the wet season. It means that you must get ready to do all of that work you can in the dry season.
 The CHAIRMAN. You expect to keep rivulets out of the cut?
 Mr. STEVENS. Not altogether. I expect there are times when you will have to abandon certain parts of the cut. During the storm there yesterday, in a couple of hours probably two inches of water fell. It was a tremendous fall.


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