From The Underground – tiles for tube stations using the system’s own waste

Designer Jeffrey Miller crafts From the Underground – tiles for the London Underground utilizing the transit system’s own waste. Intrigued? Tiles are a defining feature of the London Underground – yet their material origins are often unknown. 

Typically, virgin resources extracted through open-pit mining are used in production. 

To address this issue, From the Underground tiles are seamlessly created utilizing waste materials produced either from the construction or operation of the tube – London clay and iron oxide-rich dust.

Naturally forming London clay is the soil on which most of the city is built and is excavated during tunnel boring. On the other hand – iron oxide dust is formed by train wheels as they grind against steel tracks every day.

A spark for this innovative idea came when he was sitting on the Central line, listening to the loud screeching as the train hurtled through one of the oldest sections of the railway.

Curious about the byproduct of all that friction, he began his research and found a study that identified the main component of the dust as iron oxide – a chemical compound that Miller, a practiced ceramicist, knew could be used to pigment glaze.

The dust is visible as a black substance on the train tracks and other nearby areas.

However, obtaining the dust proved tricky and Without a collaborator at Transport for London (TfL) – the local government body that runs the network – he had to collect it himself, going from station to station with a vacuum cleaner.

“I didn’t vacuum the actual tracks because that was maybe a little bit too risky – but I vacuumed the grooves on the platform right before you step onto or off the train and a lot of dust had collected in there!” shares Miller.

Although the dust was mixed with contaminants, he embraced the slight imperfections that this brought to the glaze.

Additionally, the idea to utilize London clay, meanwhile, arose through conversations Miller had with a geologist, who gave him a contact who worked on tunneling projects in London and could provide waste-borehole samples full of the clay.

But the challenge with using the clay was that it took a lot of processing and testing to get it to a stage where it could be used to make objects.

The process behind ‘From The Underground’ involved – drying out the clay, crushing it, reconstituting it with water and then filtering out the non-clay particles before mixing it together again and testing how it behaved when fired in the kiln.

“Working with wild clays is rewarding – usually in ceramics, you don’t really get access to this process and it’s quite nice to be almost filling in all the gaps along the route of the creation of something!” he adds. 

Lastly, Miller’s clay tiles are further cast in an art nouveau design that was already utilized in some of the network’s older stations. 

Tiles are cast from molds provided by H&E Smith – a tile manufacturer which refurbishes tiles for the London Underground – and was originally designed by Leslie Green, the architect behind many iconic London Underground stations in the early 20th century.

“The whole crux of this project was seeing how the underground – which is this very uncommon place for resource extraction – could be used for resource extraction. I didn’t think when I started that it would be something that could be scaled up until I started working on it and realized the scale of the materials that are involved.

For the clay, you’re dealing with hundreds and hundreds of metric tonnes for an excavation of usable material and for the iron oxide, there’s 400 kilometers of track along the underground and it gets covered in this black stuff that they have to dispose of quite regularly!” concludes Miller.