Bridge Utilities Infrastructure News


Bridge Utilities Piping for Drawbridges 101

Posted by Edward Dill on Apr 18, 2018 9:08:00 AM



Drawbridges are special.

There are hundreds of drawbridges in the United States spanning canals, rivers, bays, and other bodies of water. Many are fifty years old or older. As these bridges age, cities must make difficult choices about whether to invest in the significant repair work required to keep them operational. Chicago, for example, one of the drawbridge capitals of the world, has over 60 drawbridges, only 43 of which remain operational today.



How Do Drawbridges Work?

Most modern drawbridges work through counterbalance. Underneath the bridge piers, a heavy counterbalancing material – usually concrete – is lowered in order to raise the moveable sections of the bridge. These sections are almost always raised in order for high-rising boats or ships to pass through the water below. When it’s time for those bridge sections to be lowered, the raised portions are slowly drawn back into place, usually by motors. Although historical drawbridges were one-sided, also known as “one-leaf,” most of today’s drawbridges are two-leaf, opening in the middle.

Because of their opening mechanisms, drawbridges require significant traffic infrastructure that alerts, stops, and directs moving vehicles and pedestrians on either side of the bridge.


Drawbridges are Inherently Complex

Drawbridges have, quite literally, a lot of moving parts. The nature of drawbridge structures makes the process of attaching and maintaining bridge-supported utility pipes especially complicated. On most drawbridges, utilities typically run along the portions of the bridge that are stationary, then run underwater beneath the section of the bridge that moves. This makes maintaining these utilities a highly specialized endeavor, requiring expert technicians and several types of equipment.

In some cases, drawbridges past the age of their functional lifespan can readily be converted into traditional stationary bridges. In these situations, utility pipes can be retrofitted to span the length of the bridge itself (entirely above water) to avoid some of the common maintenance pitfalls of underwater piping. Converting a drawbridge and its attached utilities is a serious undertaking and requires all contractors to work together to ensure a minimally disruptive transition.


Aptus: The Under-Bridge Utilities Expert

The Aptus team has extensive experience maintaining and installing bridge-attached utilities on all kinds of bridges, including drawbridges. We’ve worked on over 2,300 bridges in more than 40 different states; the older America’s bridges get, the more complex their utility projects become.

People across the country rely on the utility connections supported by hundreds of thousands of bridges in the U.S. From natural gas to fiber optic cable, bridges – even drawbridges – are an incredibly important factor in keeping Americans connected to the utilities they rely on.



For more information on how Aptus’ team of experienced professionals can lend a hand on your next bridge utilities project, reach out to one of our regional representatives right now.


Topics: Bridge Utilities, Bridge Piping, Drawbridges