I’ve always had a lot of respect for engineers and have been actively trying to convince one my kids to consider the profession. A well-engineered tool can mean the difference between anything from being hungry or full to being dead or alive.
My father loved watching war movies which meant I watched a lot of war movies as a kid. Obviously, the action is hard to miss but all the thought and planning that went into constructing the massive machines that filled the screen fascinate me. In the movie A Bridge Too Far we see Elliott Gould lead a team constructing a bridge near the Dutch town of Son en Breugel as part of the United States involvement in Operation Market Garden.
The whole story is fascinating, but it blew my young mind that they spent such a large part of the story discussing the construction of and important of bridges. This lead to further reading on the importance of engineering and its impact on the success and failures of both sides of WWII and beyond.
In that scene they constructed a Bailey Bridge designed by Donald Baily a civil servant in the British War Office. He was a model building hobbyist who had heard of the challenges the Allied forcers were facing with getting tanks and other heavy equipment moved across the many rivers of the European theater.
Many of the mobile bridges in use at that time like the Inglis bridge made popular during the first World War either required specialized machinery to construct or could not hold up to the massive weight of the tanks in use at this time like the British Churchill Tank (40 tons) or the American M3 Medium tank (30 Tons). These tanks were heavily armored but agile enough to climb making them very effective in combat but if you couldn’t get them to the battle they were useless.
Bailey sat out to design a bridge the could fit in a single service truck, with pieces that could be lifted by just 6 soldier, be simple enough to be constructed with minimal training and could be deployed without access to the other side of the river or gap. Taking a modular approach and redesigning the supports to have a diamond shaped truss that was both flexible and strong he made a bridge that was better suited to support the increased weight.
As the pieces of the 570 lb. bridge panels were snapped into place and secured with pins they could be pushed across rollers to the other side. Links would be added to the first segment to make it tilt upwards in the front as it approached the opposite bank and extra panels would be added to the back to prevent it from tipping over.
These bridges quickly became an indispensable tactical trend and by 1945 helpful facts about building Baily bridges were being added to war manuals alongside things like German armament. The Bailey bridge was described by General Eisenhower as one of the three most important engineering and technological achievements of WWII, along with radar and the heavy bomber.