Image credit: Renee Del Missier, The dramatic lozenge roof of Vienna Central railway station allows natural light to flood the building

Galvanized steel has contributed significantly to UK rail infrastructure for decades and is used abundantly in infrastructure

The Department for Transport’s 2021 plan, Decarbonising Transport: A Better, Greener Britain envisages ‘a net zero rail network by 2050, with sustained carbon reductions in rail along the way.’ Alongside the removal of all diesel-only trains from the network by 2040, extensive, ongoing electrification works and the introduction of new battery and hydrogen trains will form part of a layered strategy to create a shift towards cleaner travel.

Whilst the uptake of new technology, better transport integration and new ways of operating are seen as key to encouraging an increase in annual rail mileage, the construction of new rail lines and the material improvements to existing networks are also important. The way we build and design these projects will significantly impact how better and greener the new vision can be, including the materials we choose, the local nature of the supply chain and the maintenance schedules that we build into the infrastructure.

Embracing circular principles will be key
Choosing adaptable materials that can be kept in a constant loop of use and which eradicate end of life scenarios is central to circular construction. But building for tomorrow does not mean overlooking the materials of today. Galvanized steel has contributed significantly to UK rail infrastructure for decades and is used abundantly in infrastructure, overhead line support steelwork, concourse structures and as a reliable solution for station construction and platform architecture. Going forward, the role of galvanised steel need not diminish as galvanized steel is ideally aligned with key principles central to circular design and construction:

Lasting many lifetimes
Galvanized steel offers the highest levels of durability, delivering once-only solutions that last the lifetime of a building, component or structure. This allows for an emphasis on avoiding the environmental impact of further unnecessary construction.

Image credit: David Hopkinson, AHR, Mott Macdonald

Reducing maintenance burdens
Data on the corrosion protection offered by a galvanized coating shows how the process of galvanizing steel components offers lifetime protection and reduces maintenance burdens over the lifetime of a project.

A modular material
Galvanized steel is an ideal material for reuse, as it is robust and does not damage easily. It is suited to modular design, is easily disassembled for reuse and can provide multiple life cycles of a building or structure. If a building is designed with reuse in mind, entire structures can be repurposed or individual components can be put to diverse use.

Perfect for remaking
When the limits of reuse of an existing component or structure have been exhausted, galvanized steel presents an excellent choice for remaking, as the coating  stays with the steel and no additional coating is needed in any subsequent use. Galvanized steel components can be easily adapted, re-galvanized and put back into service – avoiding the environmental burden of new steel production.

Endless no-waste recycling
Galvanizers Association, the voice of the UK and Ireland galvanizing industry, gives clear end of life information on how steel and zinc are recycled together – without loss of properties – to produce new galvanized steel. As zinc self-sacrifices at a very slow rate, recycling will not happen for many decades and dependent on location, a galvanized coating can provide over a century of use.

Recent landmark projects in the UK and Europe highlight how galvanized steel is already contributing to ambitious infrastructure design that can last multiple lifetimes. The lozenge roof of the new Vienna Central railway station is a case in point. One of the most complicated steel construction projects in Austria and winner of the Austrian Steel Construction Prize, it incorporates approximately 7,000 tonnes of steel and is six times the size of a football pitch. It can be seen for miles around and is a prime example of what can be achieved when galvanized steel is selected as material of choice from the outset. As a public transport solution, it meets both a 100-year design specification and the need for zero maintenance. In addition, the use of bolted connections for the roof structure means that the steelwork can be readapted or reused for other infrastructure projects needs should requirements change.

Projects closer to home also show what can be achieved when future thinking our station architecture and how we can adapt existing station design to cope with the projected increase in rail capacity. Many of the innovative solutions for Leeds Station Southern Entrance, situated alongside the River Aire, lie unseen below the new building, including the foundations and galvanized steel that form the ground floor concourse. The foundations comprise two concrete piers supported on piles socketed into bedrock below the riverbed. A concourse deck formed from a grillage of deep steel beams, supports the superstructure. A sizeable fifty percent of this concourse is constructed below the existing viaduct, in inclement conditions directly above the river. Hot dip galvanizing was chosen as the only method of corrosion protection with enough proven reliability for the complexities of the environment. All steelwork located above the river forming the ground floor concourse, as well as the bridges linking the concourse to the riverbanks is galvanized, offering unbeatable corrosion protection where trusted, proven performance is critical.

These and many other infrastructure projects make visible what is possible when we use materials where their strengths lie. They emphasize that a final solution for UK Rail infrastructure will be about taking a mixed approach and prioritising the efficient use of durable materials that complement each other. Viewed over the long-term, hot dip galvanizing has a long list of systematic benefits that are both reliable and quantifiable. It is a material we have prioritised for many decades already, it is suited for use for many decades to come.

 

Tel: 0121 355 8838
Email: i.johal@hdg.org.uk
Visit: www.galvanizing.org.uk