Instructions on Modern American Bridge Building by G. B. N. (George Bates Nichols) Tower
page 43 of 57 (75%)
page 43 of 57 (75%)
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very stiff bridge, and similar to the one at Bellows Falls, both
having their axis oblique to the channel of the stream they cross. The timbers could hardly be procured now, except at great expense. No. of Upper Lower Span Pan- Rods Chord Chord Braces Counters Uprights Arches els 182 14 21 2--8 x16 2--8 x17, 1--21 x8 1--8 x10 21 x11 2--8 x9 1--5 x16 2--4 x17, 1--5 x17, Diagonals 6 x 8, Rods 7/8. Floor timbers suspended both from arches and truss, 9 x 13; stringers 10 x 14. In the Cheshire Bridge, the braces are only 20x8, and the span is only 175 feet, the number of Panels being 14, as in the W.R. Bridge--the other dimensions are the same. Below are given the dimensions of a Howe Truss of 108 ft. span, weight to be borne on upper chord. No. of Upper Lower E. Floor Rise Camber Pan- Chord Chord Braces Counters Rods Timbers Ft. Ins. els Ins. Ins. Ins. Ins. Ins. Ins. 13-1/2 3 12 8--3 x12 8--3 x12 2--8 x10 1--7 x10 2--2-1/8 9 x16 As plank is used for the chords, the pieces must be bolted thoroughly with 5/8 bolts. |
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