FEATURED PROJECT: Poe Dam Bulkhead

As part of a large retrofit project at Poe Dam, Thompson Metal Fab was contracted to manufacture a new Floating Bulkhead and (5) Pier Nose Weldments.

The Floating Bulkhead is a proprietary product which allows for typically submerged areas to become ‘dewatered’ for maintenance purposes. The Floating Bulkhead is made of two basic components: the Support Beam and the Needles. Each independent ‘Needle’ is deployed in the water and floats to the horizontal Support Beam where it is eventually anchored. The Needles are then released of their air and become partially submerged and now run vertically. Once all Needles have been deployed/installed in the proper orientation, water can be successfully blocked thanks to the overlapping seals which are bolted onto the Needles. This particular unit, when completed, was approximately 49’ wide x 54’ tall and required (7) individual Needles along with the single Support Beam. The Needles were manufactured from (2) custom fabricated HSS pontoons, capped, and then sheeted with a skin plate on both sides. Because these structures are intended to float, all weld had to be ‘air tight’ and were inspected for leakage. This project also included the use of Fracture Critical Materials.

In efforts to mitigate final tolerance risks, TMF pre-planned the way we processed our materials, our fit-up plan and our weld-sequencing due to unavoidable shrinkage and distortion due to the basic design. Additionally, TMF worked with the engineer to add ‘structure’ to the design to reinforce specific areas of risk with no additional impact to cost and/or schedule.