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Life-Cycle Engineering Services | EXPANDED

Modjeski and Masters is pleased to announce the acquisition of structural engineering firm Summit Engineering Group, Inc. Our combined engineering prowess and respective technical skillsets will enable us to provide streamlined design and construction solutions to best meet client needs.

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Desiard Street Swing Bridge Replacement

| View Projects:USA Monroe, LA

  • Client:

    Louisiana Department of Transportation and Development
  • Service:

    Movable Bridges
  • Status:

  • Overview

    Side view mirrors are a common casualty for narrow two-lane bridges. That’s because they are often sheared off as one motorist attempts to squeak past another. Not only are the sacrificial mirrors at risk, drivers also can become hypertensive due to the fear of impact. Louisiana DOTD needed to take great measures to improve the end user’s experience and safety on the bridge. They also wanted to increase the navigational channel clearance on the Ouachita River. This meant replacing the 100-plus-year-old truss swing bridge. At the same time, LADOTD needed a firm that could perform the necessary tasks while minimizing the bridge outage time for construction. Enter Modjeski and Masters, industry leaders in swing bridge inspection, design and accelerated construction methods.

    The existing equal arm truss swing bridge provided a navigational channel clearance of 130 feet. To increase channel clearance to 150 feet our movable bridge experts designed a new bob-tailed steel girder swing bridge with unequal arms of 112 feet and 185 feet. This meant that construction of a new pivot pier and drilled shaft foundation could take place under the bridge and adjacent to the existing pier, without interrupting traffic. This simple solution reduced bridge outage time for construction by nearly one full year. Modjeski and Masters also proposed an innovative method for accelerating erection of the superstructure. Our design called for floating out the old truss swing on a barge, with the new swing girder bridge floated in immediately afterwards.

    Construction of the new swing bridge was completed in 2003. With a broad 30-ft. roadway, mirrors and motorists need not worry any longer. Trusted by LADOTD, Modjeski and Masters received an emergency call when the bridge was recently struck by lightning. Our immediate responder was able to trouble-shoot and restore order to the swing bridge electrical components. Some may call it just another task order. We prefer to call it Commitment Beyond Completion.
  • Description

    Tasks Performed
    • Replacement Structure – Design (Preliminary & Final)
    • Electrical/Mechanical Design
    • Construction Support & Inspection

    Bridge Geometry
    • Length of Swing Span – 298 feet
    • Total Project Length – 952 feet
    • Lanes on Structure – two lanes
  • Testimonial

    Our innovative design and construction concepts reduced bridge outage time for construction by nearly one full year.
  • Credits

    William B. Conway, PE (Principal In Charge)
    Lance V. Borden, PE (Project Manager)
    Lee R. Letnz, PE (Electrical Engineer)
    Donald L. Miller, PE (Mechanical Engineer)