Bledisloe Wharf

In 1971, a young couple embraced at Bledisloe Wharf. Their love story unfolded against the backdrop of a bustling port. This is just one snapshot in time from Bledisloe Wharf’s rich history. Bledisloe Wharf stands as a testament to Auckland’s maritime heritage. It has witnessed countless ships come and go, carrying goods and people from all corners of the globe. Constructed in the late 1970s, Bledisloe Wharf was an innovative feat of engineering. It utilized precast and prestressed I-beams and panels. These formed the base for the deck slab overlay. Piles, headstocks, and quayside beams were poured in situ. This created a strong and durable structure ready to handle the demands of a busy port. However, the harsh marine environment took its toll. By the late 1990s, routine inspections revealed a severe chloride contamination. Corrosion was evident in many areas. The problem was compounded by two key factors. Bilge water discharge from a ship had created a varnish-like coating on the lower surfaces of the I-beams. This trapped moisture and chlorides within the concrete. Secondly, tidal washing, splashing, and salt-contaminated rainwater seeped through the deck. This further exacerbated the corrosion issue. Initially, a cathodic protection system was installed on the most affected beams. However, it soon became apparent that the entire structure was at risk. The cost of extending cathodic protection was prohibitive. In 1999, a solution arrived: the AQURON 7000 System. This involved high-pressure water blasting and sandblasting to clean the affected areas. Then, AQURON solutions were applied to every exposed surface. Specialized boom equipment was used to apply the treatment even to the underside of the deck. The treatment proved successful. Tests conducted in 2008 showed that the corrosion had been arrested. Bledisloe Wharf stood strong once more. Bledisloe Wharf continues to play a vital role in Auckland’s port operations. It stands as a symbol of resilience and innovation in the face of environmental challenges.