Case Studies

Port Allen Lock guide wall

In August of 1997, officials of the Port Allen Lock decided to put Seaward’s SEATIMBER Composite Marine Timber to the test on the Intracoastal side guidewall of the lock. Last February, six months after the first successful installation, Seaward delivered a second shipment for the Mississippi River side of the lock.

Located on the west bank of the Mississippi River in Port Allen, Louisiana, the lock affords vessel and barge traffic access between the Mississippi River and the Morgan City-to-Port Allen stretch of the Gulf Intracoastal Waterway. The 84-foot wide (26m) structure has 1,202 useable feet (366m) of gate bay, with approach bays and guidewalls to combat the effects of river currents on entering and exiting vessels.

The Mississippi River side of the lock, where the second shipment of SEATIMBER product was installed, takes the hardest abuse from entering vessels and is where maintenance crews were replacing broken wooden wale beams as much as ten times per year. Occasionally surprised by the force of the currents, vessels contact the guidewalls harder than expected. Before the SEATIMBER installation, the results were recurrent expenses and another day’s work for the maintenance crews.

Close-up of the SEATIMBER guide wall used at Port Allen Lock

After replacing a 235-foot (72m) section of guidewall wale beams, installation crews noted the ease of installing the 12 x 12-inch (300 x 300mm) SEATIMBER Composite Marine Timber and reveled in the fact that they did not have to wear protective clothing or use wood preservatives to work with the SEATIMBER material.

Asked about the performance, Tim Connell, Assistant Operations Manager of the Army Corps of Engineers' Gulf Intracoastal Waterway Project, said: “SEATIMBER has shown itself to stand up to serious impacts that would have surely broken timber. We have video footage that shows a tug and barge striking the wall with enough force to break the 1-1/2 inch (38mm) tow cables, but the guidewall sustained no damage and remains intact today.” You can download the video clip here.

Connell further stated he was pleased with the ease of installation because the 80-foot (24m) length of the members reduced by three the number of crane picks and butt joints that would have been required. In addition to the tremendous time savings, the reduction of joints in the guidewall sections allows for greater section stiffness than that of the original wooden members, while the flexural properties of the SEATIMBER material give it the advantage of absorbing impacts without damage. Seaward is proud to be part of the solution at the Port Allen Lock.