This 1944 cover image is one of the first photos to be published of a Bailey Bridge, a piece of equipment that proved invaluable to the Allies in World War II, and has since gone into wide use globally.

Invented by Donald Bailey, a British civil servant, in 1940, it first saw service in the North Africa campaign in 1942. A portable, prefabricated truss bridge, each of its 10-ft-long, 5-ft-tall sections consisted of 17 parts.

Each cross-braced rectangular unit weighed 570 lb and could be carried by four soldiers. No special tools or heavy equipment were needed to assemble them. The modular units could be bolted together to form spans of over 200 ft, and were strong enough to support tanks.

Thousands of Bailey Bridges were erected by Allied forces across the European and Pacific theaters, enabling units to advance across rivers or ravines in areas where retreating enemy forces had destroyed bridges.

British Field Marshal Bernard Montgomery paid this tribute: “As far as my own operations were concerned, with the Eighth Army in Italy and with the 21 Army Group in North West Europe, I could never have maintained the speed and tempo of forward movement without large supplies of Bailey Bridging.”