Spanning the Firth of Forth (photogravure supplement)
Photogravure Supplement - 1
THE TAPERING UPRIGHTS of the central towers, from which the Forth Bridge cantilevers extend, consist of steel tubes, 12 feet in diameter. They taper inwards, from 120 feet apart at the base to only 33 feet apart at the top. The whole structure is held together by a complex arrangement of cross-bracings of lattice steelwork.
Photogravure Supplement - 2
AT THE BASE OF EACH CANTILEVER the “skewbacks” or connexions of the 12-feet tubs, are extremely complicated in arrangement. From the skewback steel tubes, splayed fanwise, extend to the top member of the cantilever, as may be seen in the photograph of the Fife cantilever. The skewbacks of the Forth bridge are more than 40 feet long.
Photogravure Supplement - 3
A NETWORK OF LATTICE GIRDERS strengthens the cantilevers of the Forth Bridge so that it will withstand a wind pressure of 56 lb. to the square foot. This photograph shows the lattice steelwork in a cantilever at rail level.