Digital Bridges:
downloadable 19th
century literature about historic bridges.
Historic American Engineering Record:
Online presentation of the HAER collections includes engineering drawings, photographs
and data pages with written histories.
National Bridge Inventory The
NBI is an online searchable database compiled from the 2006 state bridge inventories.
It enables easy searching for technical specifications of public bridges.
Caution:
since the 2006
Ohio Bridge Inventory on which the NBI is based substantially overstates the number of remaining historic truss bridges
use this website (not the NBI) as the
benchmark for determining the existence of old truss bridges. The 2006 Ohio Bridge Inventory also
erroneously identifies most pony truss bridges as through
trusses.