The historical Ouachita River Bridge, built around 1906, is located in the City of Monroe, Morehouse Parish, Louisiana, at Milepost VD 72.0. The bridge carries one railway track over the Ouachita River and is currently owned and operated by the Kansas City Southern Railway Company.
The structure consists of a 242-foot riveted steel through truss east approach span, a 294-foot riveted steel through truss movable swing span and 242-foot and 120-foot riveted steel through truss west approach spans with a total length of 899-foot. The swing span bridge is a rim-bearing design, symmetrical about a pivot pier with a structure width of 19-foot center to center of trusses. The operation of the swing span is totally manual with the use of hydraulic levers and operator skill.
There have been numerous structural, mechanical and electrical repairs/replacements over the years on the 100-year-old historic bridge as would be expected. Recently the pivot pier has settled resulting in a shift to the north which seriously affected the operation of the bridge and resulted in corrective measures being undertaken to compensate for this movement. The existing pivot pier is a masonry pier on timber piles.
H&H’s extensive and renowned movable bridge expertise was utilized on the movable structure. The first phase of the project was to carry out detailed structural, mechanical and electrical inspections and evaluations of the swing span portion of the Ouachita River Bridge.
These evaluations would assess the current condition and load rating and to provide recommendations for remedial work to extend its service life for at least another 10-15 years. The chosen option was to repair the center pier machinery, replace the pinion shaft bushings and the center pivot pin and to fully automate the operation of the bridge with provisions to operate the bridge remotely. The existing manual operation will be maintained for redundancy.