Handbook of Railroad Construction; For the use of American engineers. / Containing the necessary rules, tables, and formulæ for the location, construction, equipment, and management of railroads, as built in the United States.

by George L. Vose

	Tension.	Compression.	Cross Strain.
Cast,	300	1,666	31.68
Wrought,	1,000	733	55.40

OF THE STRENGTH OF BOILER PLATES.

219. The strength of rolled boiler plates is no greater in the direction of the fibres than crosswise, but is more regular; whence the length of the fibre must be placed as nearly as possible with the direction of the force.

A mean of twelve experiments, by Mr. Fairbairn, gives the tensile strength of wrought iron plates as 50,960 lbs. per square inch; and the compressive strength of plates, when built into tubes, as 30,464 lbs., or for safe use in practice, for extension, 12,740 lbs., and for compression, 7,500 lbs. In the remarks upon girder bridges the matter of riveting will be considered.

CLASSIFICATION OF IRON BRIDGES.

220. Iron bridges may be classified as follows:—

Those entirely of cast-iron, or Arch and Girder bridge.

Those of wrought iron alone, or Tubular and Girder.

Those of iron wire, or Suspension bridges.

Those of cast and wrought iron, or Trussed bridges.