The Pittsburg and Lake Erie Railroad Cantilever Bridge Over the Ohio River at Beaver, Pa.

As the business of a railroad increases, it becomes necessary in many cases to change its facilities, and frequently a change in one department necessitates many and serious changes in others. The Pittsburg and Lake Erie—the road of the New York Central Lines into Pittsburg—is a striking example, for its management has spent vast sums of money to keep it abreast or a little ahead of the requirements of increasing traffic. Its bridge over the Ohio River at Beaver, Pa., built in 1878, had to be renewed by 1890, which was done on the singletrack masonry by building a bridge which at that time was thought to have strength sufficient for many years. It was built for loadings equal to Cooper's E-30, with low unit stresses.