Next time you are standing on a station, waiting for a train, look down. Not at your feet – past those. What’s down there? On an older station it may be paving slabs, or tarmac. If it’s a newer platform, or a recent extension, it could be a fibreglass panel, or a concrete slab.
But what’s under that? Rubble fill retained by a brick wall under the platform coping stones? A complex arrangement of piled steel sections and cross braces with a glass-reinforced polymer (GRP) deck on top? If it was built in the last ten years, it could even be a block of expanded polystyrene. You know, the stuff that TVs come packed in when they are delivered in a box.
It seems an unlikely material to use for station platforms, but, actually, it’s a good choice – easy to install and simple to modify.
It all started over ten years ago. A chartered surveyor named George Rowe saw expanded polystyrene being used to fill voids under platforms in the Netherlands, and thought it was a great idea.