Orthotropic Steel Bridge

What is an Orthotropic Deck?

  • Steel Orthotropic Deck
  • Developed in Germany in the 1930's, similar to United States (U.S) Battleship decks.
  • A thin steel plate has a series of longitudinal "ribs" and floor beams, wearing surface.
  • 100% steel superstructure.
  • Can see same principles on everyday level with some types of cardboard.

Why is it being used?


  • Prefabricated in a shop, which results in faster construction and higher quality control.
  • Lightweight, which is a critical characteristic for movable bridges.
  • A lighter weight allows the bridge to be more efficient, and also allows for faster operation.
  • Since the bridge is more efficient, it will require less maintenance, which will reduce lifecycle costs.
  • Highly redundant system; minor cracking is often just a nuisance rather than a serious structural threat.
  • Allows for longer span lengths, which provides a better riding surface than others since it contains less connections.
  • Good cold weather constructability, since there is not a temperature requirement for concrete to cure.
  • Corrosion resistance has historically been very good, partially from wearing surface and closed ribs.


  • Higher initial fabrication cost, but offset in the long run since less maintenance costs.