Bridges presentation
The illustration is from
Wilhelm Wethofen's article published in Engineering
Magazine, 28 February 1890.
The world's most famous cantilever also is one of the world's first and largest steel bridges and held
the record for longest cantilever for 27 years. Pontists are familiar with the brilliant demonstration
used by Sir Benjamin Baker to illustrate the structural principles of the Firth of Forth Bridge: two
men sitting on chairs with outstretched arms and sticks supporting Kaichi Watanabe, a visiting
engineering student from Japan, sitting on a board, representing the fixed piers, cantilevers, and
suspended span. To ensure that there was no repeat of the Tay disaster, Baker conducted a series of
tests, gauging wind at several sites in the area over a two-year period, arriving at a design pressure
of 56lb/ft2 (274kg/m2), which was considerably in excess of any load the bridge would ever sustain.
annaabi.ee 
