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| Street View, Apr 2024 |
The outlet conduit in the spillway is running.
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| usbr "Elephant Butte Dam and Reservoir (originally called Engle Dam) is on the Rio Grande, 125 miles north of El Paso, Texas, can store 2,210,298 acre-feet of water to provide irrigation and year-round power generation. This is a concrete gravity dam 301 feet [92m] high and 1,674 feet [510m] long including the spillway. It contains 618,785 cubic yards of concrete. The dam was completed in 1916, but storage operation began in 1915. "The power system consists of a 24,300-kilowatt hydroelectric powerplant at Elephant Butte Dam. A system consisting of 490 miles of 115-kilovolt transmission line and 11 substations totaling 81,750 kilovolt-amperes, which was developed and operated by the Rio Grande Project until 1977, has been sold to a private electric company. "Geology "Foundation: Hard, sound, fissured sandstone in irregular beds, containing pockets and interbedded strata of friable shale and numerous small springs throughout foundation area" |
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| 6:52 video @ 3:13 History of Elephant Butte Dam It can hold over 2 million acre-feet of water. When built, it was the second largest irrigation dam in the world, and it created the largest man-made reservoir ever built. [@ 1:17] |
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| Underestimated Arsenal posted A saving of over $200,000 "without sacrificing anything in quality or durability," Arthur Powell Davis, chief engineer of the United States Reclamation Service, wrote in 1917 of how part of the cement for Elephant Butte Dam in New Mexico was made. The Service's engineers did not buy all of it. Nearly half was sandstone, taken from the quarry that supplied the dam's concrete stone and ground together with Portland cement. They called the blend sand-cement. Western Engineering reported in June 1916 that it averaged 52 percent Portland cement and 48 percent sandstone. Why not simply buy cement? The dam stands on the Rio Grande, 125 miles north of El Paso, Texas. Until a branch railroad opened on 2 March 1911, everything came by wagon from Engle, 12 miles away. "Sand-blending of cement is a subject well worthy of general recognition, especially on work in remote locations, where high freight rates and long wagon hauls combine to make the cost of Portland cement excessive," Engineering Record said in October 1913. Why not make every sack of cement on the spot? Engineering Record answered that too. There was material near Elephant Butte for making cement, but the shorter haul and the lower price of cement made the saving from a full cement plant too small to justify the expense. Grinding rock into cement that was bought was another matter. Ground rock sounds like a weaker cement, and the Service did not take it on trust. It had weighed the idea since 1904 and begun long laboratory tests in 1905. In 1911 it investigated the materials available at the dam site. The mill was designed by R. R. Coghlan, with O. L. McIntyre and L. J. Charles, and it was ready on 1 March 1913. Concrete began going into the dam on 3 June. A gyratory crusher broke the sandstone. A rotary dryer took out moisture where the rock needed it, and a ball mill ground it. An automatic mixer blended in the Portland cement, and four tube mills, the machines that did the fine grinding, finished the job. Davis gave the fineness as 90 to 93 percent passing a No. 200 sieve, and the powder was smaller in grain than Portland cement itself. A laboratory at the mill tested what came out. In general, the blend had to pass the standard tests for Portland cement, except those for specific gravity and chemical composition, and a 200,000-pound compression testing machine tested samples of concrete taken from the mix as it went into the dam. Why would rock work? Western Engineering said sand-cement develops properties "but little, if any, inferior" to Portland cement when used in mass concrete, and that making it involves no chemical reactions. All it asks is that the rock be ground fine enough to mix completely. The mill turned out more than 620,000 barrels before it stopped in January 1916. It cost $70,000, and Western Engineering reported an estimated saving of $250,000 against Portland cement alone. Concreting on the dam was completed on 13 May 1916. Wiring of the lamp posts along its top followed close behind, and on 26 May the dam was lit for the first time. Louis C. Hill, the Reclamation Service supervising engineer who described the mill and mixing plants for Engineering Record in October 1913, later served as president of the American Society of Civil Engineers, the society says. So did Arthur P. Davis, whose 1917 book, Irrigation Works Constructed by the United States Government, is quoted in the post. At the mill, the busiest month was March 1915: 40,205 barrels of sand-cement at $1.494 a barrel, Davis wrote. Engineering Record said in 1913 that the layout of the concrete mixing plant needed only two men to operate each mixer. And before April 1915, when concreting had advanced far enough to cut the placing crews from four to one, about 1,300 employees were at work on the dam, the Service's 1914 to 1915 report says. After that, 370. About the photograph: the Library of Congress holds this print from the Reclamation Service and dates it 1916 or 1917. It cannot show the mill, or what the concrete is made of. It shows the finished face and the lamp posts along the crest. The Library's note calls the three towers at the far end "electrical(?)", but they look like the dam's cable towers, which Engineering Record photographed in 1913. The print was warm sepia. It was changed to plain grey and cropped to remove its grey mount, and nothing inside the picture was altered. Where the words on the photo come from: "Nearly half": Western Engineering, June 1916, gives an average of 52 percent Portland cement and 48 percent sandstone. The Service's 1912 to 1913 report says the sandstone was blended in proportions of 45 to 50 percent by weight, and Davis says the automatic mixer joined equal quantities. So the post says nearly half. "For years": the 1912 to 1913 report says the Service began long laboratory tests on sand cement in 1905, and Davis says experiments extended over several years. The first concrete went into the dam on 3 June 1913, the 1915 to 1916 report says. "The dam's own quarry": the 1912 to 1913 report names sandstone "from the quarry from which rock for concrete is obtained". "A mill built at the site": Davis describes the plant, and Engineering Record said it was ready for operation on 1 March 1913. The figures differ between sources. The mill cost $56,000 in Davis and in Engineering Record in 1913, and $70,000 in Western Engineering in 1916, which the post uses beside the saving it gives. Davis's text puts the total made at 622,551 barrels; the Service's 1915 to 1916 report and Western Engineering say 621,550. The post says more than 620,000 barrels. Elephant Butte Dam, near Truth or Consequences, is 301 feet [91.7m] high and 1,674 feet [510m] long including its spillway, the Bureau of Reclamation says. It still stores water there for irrigation and power, and the American Society of Civil Engineers lists it among its historic landmarks. Rico Ludovici: That was half the reason for the St. Francis Dam failure in Newhall, CA, 1928. Local aggregate was porous and took up water. When CONCRETE [n.b. not 'cement'] becomes saturated, it loses density vis a vis the water and starts to approach buoyancy in moving water. When the water carries a lot of sediment, it starts to approach the density of the concrete. Materials testing, guys. And a friend who works in high-value commercial construction in Los Angeles tells me they are running out of high density, high strength aggregate in that area. They now have to import it from distant sources. Like Greenland. |
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