Throwback Thursday: Early Large Engineered Wood Structures

There’s a lot of buzz in the world of wood these days about building tall. Designs for high-rise buildings with wood as a main structural component are possible today thanks to engineered wood products like glued-laminated beams and cross-laminated timbers.

A century ago, the construction of large structures was limited by the size of the wood cut from trees and the methods of connecting the members. As Forest Products Laboratory (FPL) researchers amassed knowledge of wood properties, adhesives, and connectors, the use of wood in structures expanded greatly. Here are a few early examples from the 1940s.

Baird Creek Bridge, 1940s

Baird Creek Bridge, 1940s

The Baird Creek Bridge in Washington was an early masterpiece in timber trestle construction. The bridge was 1,130 feet long and 235 feet high. Wood members were held together with a split ring connector at each end connection.

U.S. Navy hanger, 1940s

U.S. Navy hanger, 1940s

The wood structure under construction in the photo above was to be used for storing lighter-than-air airships like dirigibles for the U.S. Navy. The hangar is 1,058 feet long and 174 feet high, with a 234-foot clear span. It required over 3 million feet of fire-retardant lumber.

(Excerpt from John Koning’s book Forest Products Laboratory 1910-2010: Celebrating a Century of Accomplishments.)