Home News High-strength Lean Duplex for tram shelters

High-strength Lean Duplex for tram shelters

The city of Barcelona’s new tram shelters are made of steel tubes from Lahti

Already before the COVID-19 pandemic, the City of Barcelona decided to invest in public transport and build a new tram line along one of the city’s busiest streets, Gran Via de les Corts Catalanes, also known as Gran Via. Like other large cities, Barcelona encourages its residents to use public transport more instead of their own cars to reduce traffic congestion and air pollution from private car use.

However, the extensive project could only be launched after the COVID-19 pandemic in 2021. When completed, the new tram line will be approximately 5 km long and will connect to the pre-existing tram line network. The project will be carried out in two phases, and the first section of about two kilometers is scheduled to be completed by next spring. There will be a total of 22 tram shelters along the first route, which will be built to a large extent from Finnish stainless steel.

Maintenance-free stainless
Stainless steel is a maintenance-free material that, after installation, does not require any maintenance, painting, or other chemical treatment in order to maintain its resistance to corrosion. Moreover, stainless steel is a visually striking material.

The aim of the design/engineering office chosen by the City of Barcelona was to find a material for the shelters that would not rust and would withstand the challenges posed by the maritime climate. The designer’s initial idea was to use grade 316 austenitic stainless steel in the project.

Khaoula Loukili, Sales Manager at Thyssenkrupp Materials Ibérica, has years of experience working with stainless steel grades. When considering the best possible option for the project in question with her own customer, Khaoula, encouraged by Stalatube Oy’s Export Manager Heidi Simberg, ended up suggesting Stalatube’s high-strength LDX 1.4162 Lean Duplex instead of the 316 austenitic steel mentioned in the invitation for tenders.

Strong, corrosion-resistant, and environmentally friendly

Stalatube’s high-strength steel tubes guarantee that the rectangular hollow sections used in the shelters are first and foremost strong and corrosion-resistant. Being a seaside city, the air in Barcelona has a high salt content, which sets high requirements for the choice of steel grade. As stainless steel is 100% recyclable, it is also the most environmentally friendly option. Almost 80% of Stalatube’s raw materials already consist of recycled material. In addition, the thickness of the high-strength tubes could be reduced thanks to the strength of the material. The size of the tubes could be shrunk from the original 160x80x6 mm to 150x100x5 mm, which also resulted in savings on raw material and transportation costs.

Stalatube’s Account Manager Heidi Simberg is pleased with the seamless cooperation with the customer.

In every project, it’s important to understand not only the customer’s requirements but also what purpose Stalatube’s products will ultimately serve. The designer may not always be familiar with all the options available in stainless steel.”

Taking advantage of expertise in all stages of the project
Using a shared tool proved worthwhile. The project’s design office provided the steel tube manufacturer with an Excel tool that could be utilized to calculate the required tube measurements. With the tool, an optimal outcome that best met the designer’s requirements was found.

We are the best experts of our own products, which is why we encourage customers not to hesitate to take advantage of our expertise and experience. We have a range of different options available and we always want to offer the customer the most optimal alternative for their project. That’s why we’re happy to be involved in the design process from the outset.”

Heidi Simberg

Documentation of the tubes is also an important part of the process. The tubes used for the tram shelters had to be CE marked. A material certificate was also delivered to ensure quality.

Savings with the cut-to-length service
The project required several different lengths of tube that differed from the standard length. The customer is very happy with Stalatube’s cut-to-length service. The tubes delivered to the customer were manufactured in the desired lengths at the Lahti plant. In this way, the customer was spared from having to cut the tubes on site as the products were delivered already cut to the required length. This also resulted in zero material loss in manufacturing. The surfaces of the tubes were polished to a satin finish by a Spanish subcontractor chosen by the customer. The round corners of the tubes were ground by hand.

The cheapest is not always the most cost-effective

Since high-strength Lean Duplex as a raw material is generally more expensive than an austenitic material, did the project end up being more expensive than originally estimated?

In the end, the costs of the project are exactly the same because we achieved a more durable end result with a smaller amount of raw material and saved on transportation costs thanks to the reduced total weight of the tubes. In addition, the cut-to-length service saved the customer one entire work stage, which translates into a smaller amount of material needed and lower labor costs. On top of everything else, this solution is, above, all, the most environmentally friendly one at all stages.”

Khaoula Loukili

The project is a demonstration of cooperation where all parties to the project – designer, wholesaler and tube manufacturer – work together to find the best possible solution for the end customer. All parties are satisfied with the result. And more shelters are in the pipeline, as construction of the second section of the tram line will begin as soon as the first section is completed. A small part of steel tube expertise from Lahti is now a visible feature of the cityscape of Barcelona.

The first tram shelter is already up on Gran Via. Next summer, the Lahti-based Stalatube’s steel tubes will be an eye-catching feature of the cityscape of Barcelona. Grade 316 flat bars welded together with Lean Duplex tubes were used as the roof material.

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Heidi Simberg

Export ManagerHollow sections & profiles, Transport IndustryStalatube Oy (Finland)