St. Charles Air Line Bridge
Once the longest and heaviest bascule bridge of its kind on Earth.
Key facts
- Built 1919
- A single-leaf bascule (drawbridge)
- Once the longest & heaviest bascule bridge in the world
- Main span about 260 ft long
- Still carries freight trains today
Narration transcript
Look ahead and all around now, because we are passing a piece of engineering history, the St. Charles Air Line Bridge, built in 1919. This is a special kind of drawbridge called a bascule bridge, which comes from a French word meaning seesaw. Just like a seesaw, one end of the bridge tips up into the air to let boats pass while the other end drops down, balanced by a huge counterweight. When it was built, this was the longest and heaviest bascule bridge of its type anywhere in the world, with a massive main span reaching about two hundred and sixty feet. Its name comes from the railroad it was built for, and more than a hundred years later, freight trains still rumble across it today. Building it was a huge challenge, because it had to be strong enough to carry heavy trains yet still able to swing up and out of the way for river traffic. Family tip: this is a great spot to talk about how bridges move. If you are lucky enough to see a bridge lift while you are on the water, it is an unforgettable sight, so keep your cameras ready as we glide beneath.