History

Drawbridge history goes back to the ancient Egyptians who are believed to have built and used a drawbridge around 4,000 years ago at the fortress of Quban. But it wasn’t until the middle ages that drawbridges became relatively common.

Drawbridges allowed castles and even towns to encircle themselves with moats or ditches and then limit access across these by lifting one side of a lowered plank span when unwanted visitors approached.

One of the most common types of drawbridges is called the bascule bridge which comes from the French word for rocker or see saw. It allows for the lifting of a span with greatly reduced effort due to counterbalancing.

With the advent of modern steel manufacturing, drawbridges became a cost effective way to build across navigable waters and the number of bridge installations grew tremendously. Also, the use of the electric motor allowed for the easy operation of drawbridges and they became an integral part of the transportation infrastructure across the country and across the world.

Today, many of the basic principles involved in drawbridge design and function remain much the same as they did more than a century ago. While the control methods have evolved and computers enter the norm in bridge control rooms everywhere, many modern drawbridges operate almost exactly as they would have when Theodore Roosevelt was being sworn into office.