. Bulletin - United States National Museum. Science. Figure 22.—Bollman deck trusses in the North River Bridge built in 1873 at Mount Crawford, Virginia, on the Valley Railroad of Virginia (B. & O.). Each end span is 98 ft. 6 in.; the river span is 148 ft. 9 in. (Photo 756, Baltimore and Ohio Collection, Museum of History and Technology.) such renowned engineers as Herman Haupt and M. C. Meigs An interesting application of the system was in a drawbridge, formed of two Bollman deck spans, over an arm of the Mississippi at Quiney, Illinois (see fig. 17). The first iron bridge in Mexico was e
. Bulletin - United States National Museum. Science. Figure 22.—Bollman deck trusses in the North River Bridge built in 1873 at Mount Crawford, Virginia, on the Valley Railroad of Virginia (B. & O.). Each end span is 98 ft. 6 in.; the river span is 148 ft. 9 in. (Photo 756, Baltimore and Ohio Collection, Museum of History and Technology.) such renowned engineers as Herman Haupt and M. C. Meigs An interesting application of the system was in a drawbridge, formed of two Bollman deck spans, over an arm of the Mississippi at Quiney, Illinois (see fig. 17). The first iron bridge in Mexico was erected by Bollman over the Medellin River about 1864. Another work of this period, which attracted consider- able attention, was a pair of bridges that Bollman erected over North Carolina's Cape hear Rivei in 1867-1868. These bridges were notable for their foundation on cast-iron cylinders, sunk pneumatically. This was one of the first instances of the use of the process in America, and the depth of 80 feet below the water surface reached by one cylinder was con- sidered remarkable for years afterward. In the last active decade or so of his career, Bollman produced hundreds of minor bridges and other struc- tures. In 1873 he supplied the castings for the splendid iron dome of Baltimore's City Hall and erected the ingenious water-main truss which carries Lombard Streel over Jones Falls in that city. In this structure the top and bottom chords of the central line of trussing are cast-iron water mains, bifurcated at the abutments, and joined by cast- and wrought-iron web members (see fig. 20). 96 BULLETIN 240: CONTRIBUTIONS FROM THE MUSEUM OF HISTORY AND TECHNOLOGY. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original United States National Museum; Smithsonian Institution; United States. Dept. of the Interior. Was
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