A Text-Book on Roofs and Bridges; Bridge Design. 1. Ed Volume 3 (Paperback)

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1894 edition. Excerpt: ...posts, the greatest depth for pony trusses is to be twelve (12) feet, and when floor beams are suspended it is to be nine (g) feet. Wherever possible the top chords of pony trusses and through plate or lattice girders are to be stiffened at each fl00r beam by side braces, having a batter not less than four (4) inches to the f00t. 39. When the use of side braces is impracticable, as in bridges with sidewalks, the fl00r beams must always be riveted to the posts; and the top chords, batter braces and posts should be made fifty (501 per cent wider than the usual minimum in through bridges. The sections of side braces are not to be less than the following: 2i" x 2i" x i" angles for lengths of 7 feet and under. 2l" x 2j" x 4' angles for lengths of 7 to 10 feet. 3" x 3" x " angles for lengths of 10 to 13 feet. 3Jr" x 3i', x J-" angles for lengths exceeding 13 fe'et. 40. No rods having less than three fourths (1) of a square inch sectional area shall be used in a-bridge. No channels less than six (6) inches in depth are to be used for upper chords, batter braces or posts, or less than five (5) inches in depth for other members. No flat bars less than one half (i) inch thick or less than two (2) inches wide are to be used for diagonals or chord bars; nor any iron less than one fourth (i) inch thick anywhere in a bridge, except for filling plates. No truss strut is to have a ratio of unsupported length to least diameter exceeding forty-five (45), nor.any other strut a ratio exceeding fifty (50).... 41. All spans are to be provided with some means of expanding and contracting longitudinally with a variation in temperature of one hundred and fifty (150) degrees Fahrenheit. 42. Spans of over seventy-five (75) feet are to have at one end nests of turned...