This cover photo shows Chinese engineers constructing a hand-made wooden bridge across the Tanai Hka River in Myanmar, then known as Burma.

During the 1950s and 60s, engineers and scientists sought ways to use nuclear weapons for major construction projects such as harbors, roads and even alternative routes for the Panama Canal.

This ominous-looking machine partially immersed in the Missouri River was the world’s largest suction dredge when it was introduced.

A 1972 ENR cover story said of Wiss Janney Elstner Associates in Northbrook, Ill., “It exists largely by looking for trouble, both before and after the fact of structural distress and failure.”

The Center for Oral History at Columbia University, founded in 1948, is an archive of thousands of recordings of interviews with a wide range of public figures.

This 1941 cover image shows Chrysler engineers planning the layout of the first factory for the mass production of tanks in the U.S.

On a Saturday morning in the summer of 1966, Vinton Bacon, general superintendent of the Metropolitan Sanitary District of Chicago, pulled his car into a service station near his suburban home for gas and an oil check. The attendant found four sticks of dynamite wired to the car’s engine. Only a faulty connection prevented them from exploding.

This 1940 cover photo shows a streamlined crane lowering the first rotor into position at the Hiwassee Dam in North Carolina.

As reported by ENR at the time, while the Depression deepened in the early 1930s, none of the initiatives taken by President Herbert Hoover or Congress did much to help, and some, such as the Smoot-Hawley Tariff Act, which led to higher prices, were counterproductive.

This 1935 cover shows three workers in a sewer tunnel in Chicago that is being driven through blue clay.