Water authorities in Gothenburg, Sweden, chose Outokumpu's duplex stainless steel grade LDX 2404 as the optimal material for their new waterway sluice gates installed at Gårda Dämme in October 2013.
"The authorities wanted to replace the old wooden sluice gates, which were starting to rot, as the area is vulnerable to flooding," explains Outokumpu's segment manager Anders Finnås. "Our LDX 2404 grade has crucial advantages over alternative materials such as wood or carbon steel. This is especially true now as customers require modern permanent solutions amid increasing concern about flood risks related to climate change."
High strength is obviously a prime consideration for floodgates, but the reduced need for maintenance is also a key factor. "The new sluice gates have a design life of 120 years, but in practice they will last for centuries as long as their rubber sealing is duly checked," says Finnås.
The enhanced corrosion resistance of LDX 2404 is also a plus, since the waterways at Gårda Dämme receive occasional inflows of salty sea water.
Working together from the start
"We were pleased to provide guidance for our customers and engineering partners right from the start on the optimal steel grade in terms of cost-effectiveness and sustainability," says Finnås.
Each of the five 3.1 X 2.2-meter sluice gates weighs about 7 tonnes. More than 400 tailor-made components including individually rolled plates were produced at Outokumpu's Degerfors mill and cut to shape and profiled at Outokumpu PSC Nordic for preassembly.
"The sluice gates have been in place for a year now, and the people in Gothenburg are very happy with the results. They look very attractive, though durability and functionality were the primary qualities behind the choice of material," emphasizes Finnås.
"We expect demand for stainless steel sluice gate applications to increase as water authorities in Scandinavia and elsewhere in Europe seek to upgrade their flood defenses and replace ageing gates," adds Finnås.