The Deep – a challenge for corrosion control

The Deep – a challenge for corrosion control

The Deep – a challenge for corrosion control

Keywords: International Protective Coatings, Corrosion, Coatings

Steelwork in one of the UK’s most challenging construction projects, The Deep at Hull, the world’s first submarium, is protected with products from International Protective Coatings.

This major new 70 m (£45.5 m) tourist attraction was a Millennium Commission Lottery Project implemented as a partnership between Kingston upon Hull City Council and the University of Hull. Managed on a day to day basis by the company Running Deep, it has already attracted over 375,000 visitors since it opened in the spring, well in excess of even the most optimistic annual projection.

The Deep is made up of four elements – a visitor attraction, a business centre, a lifelong learning centre and a research facility. Its aim is to create a greater understanding of the oceans and their secrets in a fun and entertaining way and to promote an understanding of the need to protect them for future generations.

The submarium tells the story of the world’s oceans through time, latitude and depth and incorporates stunning aquaria and the latest hands-on interactive displays. The main tank, 10 m deep and containing 2.3 million litres, was at the time of building the deepest in Europe with the world’s longest acrylic lift ride, bringing visitors face to face with the sea life it contains. The Deep research facility, equipped and managed by the University of Hull, will be of international importance and aims to become a centre of excellence in the field.

Sited on the banks of the Humber at its confluence with the River Hull, the whole project presented unique design and construction challenges. Part of the ongoing regeneration of the port, the disused brown field site chosen for the ambitious project was known as Sammy’s Point, after Martin Samuelson who created a shipyard there in the middle of the 19th century.

The barrenness of the site and its dramatic seascapes led architect Sir Terry Farrell to design a building which evokes a geological monolith, with fractures and fault lines patterning its surface. The building rises dramatically out of the ground and culminates in an observation point 24m up leaning over the sea, with stunning views of the Humber estuary and the Humber Bridge. “I genuinely consider that this project has the potential to be regarded as one of the most characterful and unique public buildings in Britain”, he commented.

For structural engineers Jubb and Partners and Steel Fabricators Wescol Steel Ltd, it meant creating extremely complicated steelwork to build the sloping triangular shape required, with not a square member in the job – the outer walls are inclined at 8 and 15 degrees. In addition, the 800 tons of structural steel, both inside and outside, had to stand up to some of the most corrosive environments possible.

“Coatings had to be compatible with a salt water environment, and there’s very high humidity in the building anyway – any paint coating had to take on board the humidity issues”, explained the project architect for Sir Terry Farrell and Partners, Darren Cartlidge. “The sea water is mixed in the building, using bags of artificial sea salt and fresh water. Any areas coming into contact with the salt bags also required a very high level of specification.”

The architects laid down strict criteria for the coatings to meet, requiring performance guarantees to cover all eventualities and requesting written proof and test evidence that any proposed coating systems would meet these standards. “This had to cover the coatings’ visual characteristics as well as achieving the lasting protection expected”, Darren added.

Having worked with International Protective Coatings on an earlier project – the Newcastle Centre for Life – the architects were aware of the company’s products and the technical backup available, and following discussions with International’s field personnel decided to specify solely International.

For the external exposed steel envelope, Interzone 505 epoxy glass flake coating was selected, overcoated with Interthane 990 acrylic polyurethane topcoat colour matched to a specific shade of light grey. Interzone 505 is a long-life coating, for use in the most aggressive environments, including offshore. A glass flake epoxy product, it provides very high abrasion resistance and long life performance. Similar competitive products usually use micronised glass flake, made from ground up glass. A high solid, low VOC, high-build product, it contains lamellar glass flakes, which provide a better barrier to water vapour. It can be applied direct onto blasted steel or as an intermediate or a finish coat.

Steelwork on the aquaria and other exposed areas was coated in Interzone 954, an epoxy immersible barrier coating. Ideal for highly corrosive splash zones, this product will even continue to cure underwater.

On the internal structure, where there was no stainless steel, Intercure 200HS zinc phosphate primer – a high build, fast cure coating, and Intercure 384, a micaceous iron oxide, were chosen.

Internal fire protection, where required, was supplied with a three coat system – Intercure 200 epoxy zinc phosphate primer, Interbond FP intumescent fire coating and Intersheen 54 modified vinyl sealer coating.

Ian Baldry, UK Business Development Manager for International Protective Coatings, and Regional Manager John Gilson secured the business for the company, while Technical Inspection Engineers Paul Almond and Granville Winstanley carried out regular coating checks at coatings contractors Intublast and on site, providing written inspection reports to both the project architects and engineers.

For more information on heavy duty coatings, please contact: Alison Hutchison International Coatings Limited, Stoneygate Lane, Felling, Gateshead, Tyne and Wear, NE10 OJY. Tel: +44 (0) 191 402 2661; Fax: +44 (0) 191 402 2630; E-mail: comm.enquiries@uk.akzonobel.com; Web site: www.international-pc.com