PORT MAINTENANCE
Protecting steel sheet piles A galvanic strategy for marine infrastructure preservation By Carla Neal, Vector Corrosion Technologies
S teel sheet piles are a familiar sight along marinas, ports and waterfront developments. They provide an efficient way to retain soil and protect shorelines, but in a marine environment, they face a great chal- lenge: corrosion. The challenge becomes even greater because steel sheet piles experience multiple exposure zones — from bur- ied soil to seawater submerged, plus tidal and splash zones. Protecting the steel across all of these zones requires more than a single solution. The project at Cadet Point Marina, Mississippi, provides a useful case study into how galvanic Cathodic Protection can be incorporated into the rehabilitation of an existing steel sheet pile seawall. Understanding the corrosion cell As discussed in the July 2026 edition of Pacific Ports Magazine, cathodic protection works by controlling the electrochemical process responsible for corrosion. The corrosion cell requires
One of the major advantages of galvanic anodes is their simplicity. Once properly designed and installed, they require no outside power supply and little to no maintenance or monitoring.
properly designed and installed, they require no outside power supply and little to no maintenance or monitoring. That does not mean that monitoring is impossible. In fact, it is very common to connect galvanic anodes through a junction box, so that system perform- ance can be measured over time. For remote or difficult-to-access marine structures, however, the simpli- city of galvanic systems can be particu- larly attractive. There are no rectifiers to maintain, and no electrical infra- structure required to keep the system functioning. Why sheet piles present a unique challenge Steel sheet piles in marine environ- ments are particularly vulnerable to cor- rosion. They often pass through several distinct exposure conditions, each with its own corrosion characteristics. The piling is exposed to different environ- mental conditions on each side: one side is in contact with buried soil, while the other is exposed to atmospheric, splash, tidal, and submerged water zones. The tidal and splash zones can be especially aggressive due to chloride deposits and regular oxygen exposure. The soil side presents another chal- lenge, as there as the backfill is typ- ically chloride contaminated due to the environment.
four components: Anode, Cathode, Metallic Path, and Electrolyte. The electrolyte can be seawater, soil or concrete depending on the environ- ment surrounding the steel. Cathodic protection interrupts the corrosion process by making the steel in the structure the cathode. This can be accomplished in two primary ways. Impressed current systems use an out- side power source, while galvanic — or sacrificial — anodes rely on the natural electrochemical reaction between dis- similar metals. This article focuses on the latter. The appeal of a “Set It and Forget It” system One of the major advantages of gal- vanic anodes is their simplicity. Once
The above photograph illustrates the consequences of failed coatings and prolonged exposure to a harsh marine environment, with substantial section loss visible.
32 — PACIFIC PORTS — October 2026
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