Highland Galvanizers' story
Motorway barriers perform a vital role, but most of us never give them a passing thought. Made of steel beams, the barriers, or the 'vehicle restraint system' (VRS), as they are officially known, begin life with a protective galvanized coating of zinc alloy to prevent rust. This coating lasts between 25 and 30 years at the roadside, where it slowly oxidizes until all the zinc disappears, exposing the steel – at which point the beam needs to be replaced. This creates a huge amount of waste and cost to the public purse.
Highland Galvanizers is pioneering a new way of extending the lifespan of these essential, yet often invisible, pieces of infrastructure, by re-coating beams before the rust sets in, so that the steel is preserved and can remain in use for at least another 25 years. Extending the lifespan of the VRS through reuse and refurbishment embodies a key circular economy principle: the need to keep the things we need in productive use for as long as possible.
Galvanizing is the most cost-effective corrosion protection for steel, with corrosion currently costing the UK 4% of GDP - as old beams are scrapped and new ones are made. There is also an 89% reduction in CO2 emissions by re-coating the steel rather than scrapping and replacing it.
The re-coated steel has the same strength and safety properties as a new beam. During 2018, a series of re-galvanizing trials were conducted within the South East Trunk Road Network, proving that the re-galvanising process can be considered an option for safety fence rehabilitation schemes for maintaining overall public perception of safety as well as existing standards.
Since those trials, Transport Scotland agreed to undertake a large-scale rehabilitation scheme on the M9 Edinburgh to Stirling Trunk Road that involved 1500m of central reservation safety fence.
Following beam identification, an accurate representation of the cost of the re-galvanisation process, plus the cost of any purchase of new beams could be accurately calculated. Of the 219 beams suitable for re-galvanizing, a CO2 saving of 89% was realised, which equates to 13.76/tonnes compared to the purchase of new steel. The associated cost saving of 46% was also achieved.
There are 284,369m of beams across South East Scotland, making up 58% of the barrier on the network. Assuming a 25 years life expectancy, this represents a potential 3,555 beams per year requiring re-galvanising, and a saving of 224 tonnes of CO2 per year. In practice though, there is some catching up to do, and it has been estimated that some 20% of the network should be treated now. That means in the short term, 17,746 beams and some 1,119 tonnes of CO2 saved when this project is implemented.
Useful learnings from Highland Galvanizers
Perseverance is one of the more important things to keep in mind when trying to introduce a circular concept that is new and unfamiliar.
Find an internal champion: identify someone who is receptive to the new idea in the organisation you need to reach. Highland Galvanizers found their champion as a key contractor to Transport Scotland, who was able to give them an insight into how best to approach decision-makers.
Consider the key benefits of the new idea from the other organisation's perspective. For example, while financial savings are always important, other benefits such as CO2 emission reductions could be the aspect that drives their motivation and willingness to change.
Highland Galvanizers' metrics
We are measuring how many tonnes of steel are re-galvanized.
