Grand Bayou Floodgate – Morganza-to-the Gulf Hurricane Protection System


By Supreme Integrated Technology December 28, 2021

Supreme Integrated Technology (SIT) is proud to announce the substantial completion of commissioning of the Grand Bayou floodgate as one of the final portions of the Morganza-to-the Gulf hurricane protection system.  Per the Morganza Action Coalition, “the Morganza-to-the-Gulf Hurricane Protection System is a levee, lock, and floodgate system designed to provide 100-year, Category 3 storm surge protection to more than 150,000 Americans living in coastal Terrebonne and Lafourche Parishes (60 miles southwest of New Orleans) as well as over 1,700 square miles of fresh and saltwater marsh.”  The Grand Bayou Floodgate is the most recent floodgate to be added to the protection system which consists of a 147-foot-long steel fabricated barge structure pinned to a jacketed receiving structure and approximately 268 feet of new steel floodwall, all installed in Lafourche Parish.

The barge is designed with natural buoyancy allowing it to float within the confines of the Grand Bayou Canal.  Under normal conditions, that barge structure is held in the open position by a hydraulically operated winch, allowing marine traffic to pass freely within the canal.  During adverse conditions, the barge is pulled into the closed position by a second hydraulically operated winch and then ballasted down to create a barrier to protect the area north of the structure from storm surge created by the many tropical storms and hurricanes that affect South Louisiana yearly.  When tropical storms and hurricanes develop, strong winds typically push water from the Gulf of Mexico northward which can cause severe flooding in unprotected areas in the form of storm surge.  With the installation of the floodwall on either side of the gate structure there will now be over 400 ft of new storm surge protection when the barge is moved to the closed position. 

The comprehensive civil site works, including installation of the receiving structure and installation of the 268 fof new floodwall, were completed by Sealevel Construction Inc. based in Thibodeaux, Louisiana.  The barge structure fabrication and outfitting were completed by Conrad Industries in Morgan City, Louisiana.  For SIT, the scope of work was substantial, as we were responsible for providing a turnkey integrated solution for controlling all operational aspects of the barge. This included a custom diesel engine pump skid assembly equipped with a 375-horsepower diesel engine, an auxiliary and direct PTO, hydraulically actuated pump drive assembly, integral hydrostatic transmission, and a centrifugal pump capable of 11,000 gallons per minute of output flow of water.  The skid assembly also included an integral 300-gallon fuel tank and fuel polishing circuit along with several hydraulic pumps to supply pressure and flow to the various hydraulic systems onboard the vessel. 

Next, SIT provided a hydraulic reservoir assembly with capacity for 250 gallons of hydraulic fluid and equipped with filtration for all fluid leaving and returning to the reservoir to ensure high quality hydraulic oil throughout the system. To conduct ballasting operations, which consists of sinking or raising the height of the barge in the water by pumping water into and out of segregated hull compartments, SIT provided custom hydraulically controlled actuators and fabricated connection assemblies for valve actuation.  Each of the actuator types were specifically sized and designed for the application and were equipped with electrical position feedback to be incorporated into the master control system also provided by SIT.  In total, there are twelve complete actuator assemblies onboard the vessel.

The hydraulically operated winches are powered by a custom-designed closed-loop hydraulic system provided by SIT which can be controlled locally from a hydraulically operated control station and remotely from the master control console.  Each winch is spooled with 1-3/8” wire rope and rated for over 80,000 lbs of line pull.  To meet designed fleeting angles for operation, SIT provided custom-designed swivel fairleads and vertical and horizontal sheaves to accommodate the changes in elevation and direction of the wire rope.  The sheaves were equipped with load cells integrated into the center pins to provide load feedback to the master control system while pulse pickups provide rotational speed and direction allowing SIT to display real time load, position, and speed for each winch assembly during open and close operations. 

In the control house overlooking the barge structure, SIT provided an integrated master control station with a 19” HMI screen for soft button operation and for display of all operating conditions.  The enclosure is Nema 4X rated and houses all of the PLC components and operational devices including joysticks for barge open/close operations and pushbuttons for emergency stop and other functions.  Within the PLC, SIT provided a fully automated mode of operation for conducting ballasting operations.  In this mode, the PLC monitors the longitudinal and transverse level of the barge using inclinometers provided by SIT and opens/closes valves within each hull compartment, as required, to maintain a truly level condition for the ballast operation.  At the control station, the operator chooses whether to take on water or dispel water for ballast/deballast operations by selecting soft buttons on the HMI screen.  From there, the automated system utilizes feedback from the position indicators on each assembly to determine the open/closed condition of the device.  SIT set limits of inclination within the control system and the PLC opens and closes valves accordingly to stay within those operational limits.  This was the first time that the ballast system was provided with a fully automated mode of operation, removing the need for constant operator interaction and streamlining the ballasting operations to improve efficiency and equipment performance.

Value-add Proposition.  While this is not the first floodgate to be installed in the area, this was the first time that the majority of the operational equipment and systems were furnished by one system integrator.  This brought great value to the overall integration of the various systems and mitigated unforeseen issues between multiple scopes of work.  By working with all aspects of operation, SIT took advantage of multiple synergies to combine what are typically independent systems into one wholistic operational architecture as shown in the integrated control station in the operator house.  With all components sized for their specific application and with careful consideration of the requests and concerns of the team responsible for operating and maintaining the system once installed, SIT was able to provide a system meeting the highest quality and safest functional characteristics for this truly integrated scope of supply.  SIT is always proud to provide systems that have a such a critical and positive impact on communities throughout the Gulf Coast, the United States, and abroad.  As a sole source system integrator, SIT continues to provide the most innovative systems for movable structures to the civil, marine, defense, offshore, and industrial market segments.

What Is Morganza to the Gulf? Morganza Action Coalition. (n.d.). Retrieved October 28, 2021, from

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