Outokumpu delivers stainless steel to critical sluice gates

The new Victoria sluice gate in Stockholm, Sweden, must deal with increased flood risks and high-water flows in Lake Mälaren as a result of future climate change. By choosing stainless steel from Outokumpu for the sluice gates, the facility will have the longest possible lifespan and be basically maintenance-free, which is beneficial for the environment and society.


The sluice facility will consist of two so-called unloading channels and a sluice channel for boats. It is the unloading channels that regulate Lake Mälaren's water level by releasing water into the Salt Lake and thereby reducing the risk of flooding in the entire Mälardalen (Mälaren Valley).

“By using high-strength Forta Duplex 2205 many advantages can be achieved; no coating or future maintenance thereof is required. We see many examples of rusty steel infrastructure in need of repainting to a cost that far exceeds the cost of choosing stainless steel to begin with. Duplex stainless steel is also approx. 40% stronger than typical construction steel and that can be utilized to cut weight from the constructions” says Susanne Ingeström, Sales Outokumpu PSC Degerfors.

With stainless steel’s high surface hardness, the gates will stay protected against the wear and tear of use during months of freezing temperatures and against the impact of ice floes. Duplex stainless steel has proven the sustainable choice for the Stockholm sluice and flood gates not only because it is maintenance free but also due to its price stability and recyclability. Even after retaining its integrity throughout its service life, stainless steel is fully recyclable. Furthermore, no future needs for removing rust and consuming chemicals for rust protection can be included in the sustainability analysis.

The new Victoria floodgate was inaugurated by Crown Princess Victoria of Sweden in August 2022. The enormous construction of the sluice gate will continue for a few more years and when it is finished will be able to release 1,400 cubic meters of water per second. The previous gates' capacity was 300 cubic meters per second.



The narrow channel in the middle is the sluice channel. The two larger

The narrow channel in the middle is the sluice channel. The two larger "basins" on either side of the lock channel are unloading channels.


In the fall of 2021, the first gate to be installed on the southern discharge channel, closest to Södermalm, arrived. The first part of the Victoria Lock is estimated to be put into operation in late spring 2022. According to the plan, the second hatch is to be installed in 2023. In 2024, the work on the new regulation of Mälaren is estimated to be completed.

The new sluice facility is the floodgate between Södermalm and Gamla stan. In 1642, the first sluice gate between Södermalm and Gamla stan, Drottning Kristina's lock, was opened. The first three locks were built with shipping needs in mind, the fourth facilitated the increasing vehicle traffic. The Victoria lock, which consists of two unloading channels and a lock channel, has climate adaptation in focus. Victoriaslussen is part of the extensive Slussen project, which spans several years.


Four construction workers on Slussen flood gate.

Forta DX 2205 by Outokumpu is the most popular duplex product on the market. It offers very good resistance to uniform and localized corrosion and stress corrosion cracking in combination with high mechanical strength. Outokumpu has delivered 80 tonnes Forta DX 2205 to the project.


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Water control