Case Study: Midwest Energy Terminal Pile Remediation

The Simpson Strong-Tie® FX-70® structural pile repair and protection system was used to restore and protect 267 seriously corroded steel pileswith a corrosion-resistant protective shell.

Category: Concrete
Market: Bridge and Marine
Application: Steel pile remediation and protection
Simpson Strong-Tie Products Used: FX-70 pile repair and protection system, FX-70-6MP epoxy grout


The Superior Midwest Energy Terminal (SMET) of Duluth-Superior Harbor was commissioned in 1976 to help accommodate the low-sulfur western coal needs of the DTE Electric power plants around the Great Lakes. The terminal is owned and operated by the Midwest Energy Resource Company (MERC) and includes a wharf structure elevated on steel H-shaped piles.


The Challenge

In 1998, it was noticed that micro-organisms were accelerating the corrosion of infrastructure piles in the harbor. From 2004–2006, AMI and MERC identified the need to repair and mitigate numerous seriously corroded H piles on the SMET pier.  A major challenge of the project was providing a corrosion protection system that would hold up to the extreme winter environment and ice impacts from ships pushing ice into the piling.

The Solution

On the advice of AMI Consulting Engineers, dive inspections were conducted to ascertain the location and extent of the corrosion damage. AMI tested many different pile repair products over a period of 5 years.  The contractor, Nordic Underwater Services, along with AMI Consulting Engineers, determined that an FRP jacket product similar to the Simpson Strong-Tie® FX-70® pile repair and protection system would be the most cost-effective solution for repair and long-lasting protection of the piles. It was also agreed that the epoxy grout should be pumped into the jacket rather than poured, to mitigate the formation of air pockets in the material.


The total repair took approximately 5½ months to complete. The key to the timely execution was excellent communication throughout every stage of the project from pre-construction and manufacturing through to mobilization and installation. Simpson Strong-Tie’s RPS specialists, RPS logistics coordination team, along with manufacturing and product management in West Chicago worked closely with the contractor to insure a seamless process and successful project installation. Before the cold winter weather could intrude, the pier was fully operational and protected from the corrosive elements of the harbor.

Simpson Strong-Tie Can Help

For complete information regarding specific products suitable to your unique situation or condition, please visit or call your local Simpson Strong-Tie RPS Specialist at (800) 999-5099.



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