Editing Benjamin Baker (engineer) (section)

===Tay bridge disaster===

In 1880, Baker was called as an [[expert witness]] to the inquiry into the [[Tay Bridge disaster]], in which part of the bridge failed and collapsed into the water. Although he was acting on behalf of [[Thomas Bouch]], the builder of the first railway bridge across the Tay, he performed his role with independence and tenacity. His testified against the theory that the bridge was blown over by the wind that night. He made a meticulous survey of structures at or near the bridge, and concluded that wind speeds were not excessive on the night of the disaster. The official analysis of the failure suggested that a wind pressure of over 30 pounds per square foot was needed to cause toppling of the structure. Baker examined smaller structures in the vicinity of the bridge and concluded that the pressure could not have exceeded 15 pounds per square foot on the night of the bridge failure. Such smaller structures included walls, ballast on the track on the bridge, and both signal boxes either on or very near the bridge.<!-- Expand - did he offer a theory of the failure? This seems a gaping hole in content. -->

[[File:A Street Railway in New York - 1876 engraving.jpg|thumb|A street railway in New York 1876]]
Baker said in his statement to the court that he had built over {{convert|12|mi|km}} of railway viaduct, referring to his design of the [[elevated railroad]] in New York City in 1868, some of which still survives in [[Manhattan]] (unused). 

By this time he had already become established as an authority on bridge construction. Shortly afterwards he was engaged on the work which made his reputation with the general public: the design and erection of the [[Forth Bridge]] (1890) in collaboration with [[Sir John Fowler, 1st Baronet|Sir John Fowler]] and [[William Arrol]]. It was an almost unique design as a large [[cantilever bridge]], and was built entirely in steel, another unprecedented development in bridge engineering. Stiffness was provided by hollow tubes which were riveted together so as to make sound joints. Baker promoted his design in numerous public lectures, and arranged demonstrations of the stability of the cantilever by using his assistants as stage props.