Alltech Engineering recently entered new territory for the company by being awarded the precision equipment installation on the Cow Bayou swing bridge project near Orange, Texas. This is Alltech Engineering’s first swing bridge rehabilitation project. This center pier swing bridge opened to traffic on June 1, 1963. The bridge opens by pivoting in the middle to allow ship navigation for personal as well as commercial boat and barge traffic. Ragle Construction and Texas DOT were confident Alltech Engineering had the experience and reputation to complete the job.
This 300,000-pound bridge has tolerances as tight as 1/16 of an inch over the 180-foot and bridge span. To ensure this tolerance could be met the center bearing and balance support wheels need to be at a perfect elevation. Alltech’s precision Millwrights exceeded customer expectations by achieving final elevation numbers within .027, where the specifications are a maximum .0625. This number may seem small but when magnified over the 90 feet in either direction this number grows substantially. Alltech Millwrights also used their extensive rigging skills to install the equipment. The wheels below the bridge are 2800 pounds per wheel and the machinery below the deck at the end of the bridge is in excess of 4000 pounds per corner, all of which needs to be installed to precise numbers. When this project is complete the entire bridge will need to balance on the center bearing alone when in the open position. This work would be challenging enough on land, but it is all being done over water from a floating work platform. Alltech has had to overcome some unique challenges on this project. This is one of a few remaining operational swing bridges left, and we are proud to be a part of making it operational again.