Measuring 60x20x10m, the 1,700-tonne gate provides access to Germany’s only deep-water port for naval vessels, commercial ships, and energy carriers. The completion of the main coating work marks a key advance in a challenging project that began in 2018.
Steelpaint
has achieved a significant milestone in the renewal of Wilhelmshaven’s Great Sea Lock, applying corrosion protection to approximately 26,000 m² of steel on one of the world’s largest sluice gates.
Steelpaint’s Stelpant coating system was chosen after a two-component epoxy system from another supplier proved incompatible with autumn and winter conditions, when freezing temperatures and near-saturated humidity can render epoxy coatings unusable.
Muehlhan Germany GmbH, working alongside Hermann Maschinenbau GmbH in a joint effort for port authority WNA Hannover and WSA Weser-Jade-Nordsee, opted for Steelpaint’s single-component polyurethane system, Stelpant. This system can cure at temperatures as low as –5 °C and in relative humidity of up to 98 %, allowing coating work to continue throughout winter. This ensured the gate could be floated back into position and reinstalled for interim use.
The coating package comprised a 75 µm zinc-rich primer, Stelpant-PU-Zinc, followed by two 225 µm coats of Stelpant-PU-Combination 300. Together, these layers provide advanced corrosion protection against saltwater, abrasion, and mechanical stress in one of Europe’s most demanding marine environments.
“The zinc primer provides cathodic protection and excellent adhesion, while the polyurethane intermediate and top coat delivers abrasion resistance, flexibility and durability even under aggressive marine exposure. The system is certified by the Federal Waterways Engineering and Research Institute in Karlsruhe for use in hydraulic steel structures and for environments from Im1 to Im3 under DIN EN ISO 12944-5. This was one of the largest and toughest projects we have been involved in the last few years, but it showed exactly what our technology can do. The schedule slipped again and again and even now some areas remain unfinished, yet our coatings went on when and where they were needed and performed exactly as intended. First the Jade-Weser-Port, now the gate refurbishment and currently in progress is the refurbishment of sluice Hooksiel,” has stated Fynn Baumfalk, Key Account Manager at Steelpaint.
While the main corrosion protection on the refurbished gate is complete, minor rework and some hot work still need to be addressed before recoating. Baumfalk confirmed that the Stelpant coating system will also be used in these areas, with full commissioning of the gate expected in 2026.
The Wilhelmshaven Sea Lock, located at the mouth of the Jade where the river meets the North Sea, is exposed to salt corrosion, tidal erosion, and abrasive silt, demanding the highest level of protection. The lock regulates water levels in Wilhelmshaven’s inner harbour, strengthens flood defences, and provides safe access for both naval and merchant fleets.