An unusual application of wire cables from the 1850s: Benjamin Severson's wire-tied iron girders
The focus of this paper is two extant American cast iron girders, which are the only known examples of girders having wire cables reinforcing their bottom chords. Apart from their wire ties, what makes these girders noteworthy are their early dates and large dimensions. The earlier of the two is a 30 foot (9.15 metre), one-piece girder, manufactured c. 1854-55; four of these girders spanned a room in a Philadelphia bank. The second is a 69 foot (21 metre), 3 - section girder made in 1859; four of these still support the floor above an auditorium in Baltimore. ln both cases, the girders were tied across the bottom with pairs of cables made of bundles of parallel wires completely wrapped with wire.
Author: S.E. Wermiel