This is an upright frame, usually made in wrought iron or steel strutted by diagonal thrust beams against the engine-house wall or other solid abutments, the height to the bearings of the guide pulleys being from 80 to 1 00 ft.
On the other hand, a girder imposes only a vertical load on its piers and abutments, and not a horizontal thrust, as in the case of an arch or suspension chain.
Brunel constructed the towers and abutments for a suspension bridge of 702 ft.
Two main towers in the river and two towers on the shore abutments carry the suspension chains.
Eads, the engineer, determined to establish the piers and abutments on rock at a depth for the east pier and east abutment of 136 ft.