A public artwork built on the geometry of a record groove, machined at the scale of a railway underpass — 28 backlit translucent HI-MACS panels, 154 lines a side.
The underpass beside Hayes & Harlington station sits on the site of the old EMI factory, where Alan Blumlein invented stereo recording. The Decorators' design turns the passage into a record: two walls, 154 lines a side, radiating from a focal point on each.
The detail is where the idea lives. Every line is drawn as two lines of slightly different shape running together — the way the two walls of a stereo groove carry different channels — so the grooves read as irregular rather than mechanical.
That leaves nothing to interpret on the shop floor. The geometry arrived as data and had to come back as 28 panels of translucent solid surface, 14 to a wall, each carrying a different slice of the arc. The walls taper, so no two panels are the same. Every one of the 154 lines has to meet its neighbour across every joint — miss by a millimetre at a panel edge and the eye finds it instantly. The panels also had to come off the wall again, because the LED lighting behind them has to stay reachable.
The artwork geometry was supplied to us. Our job was to turn it into parts. Every panel was machined individually on our 5-axis CNC at Finchampstead, in 12mm HI-MACS Opal from the translucent Lucent range. Because the pattern radiates from a single origin, each panel is its own program — cut to hold the line spacing and the arc across its own width, and to register exactly with the panels either side of it.
The grooves are cut with a 3mm router bit to a depth of 2mm, each line taken in two passes, then filled with resin. Filling a groove distorts an edge, so panels were machined oversize at 1240mm for a finished 1200, filled, sanded back and only then trimmed to size. Fixing is by slotted bolt holes with counter-bored recesses, so any panel can be lifted off without disturbing its neighbours.
Backlighting sets the tolerance. Light passing through the sheet turns any variation in groove depth into a variation in brightness, so sample panels were lit and reviewed in the workshop before the run went ahead.
Supplied artwork geometry resolved into 28 individual cut files, each panel unique.
5-axis CNC at Finchampstead. Through-cut, counter-bore, slotted fixings and engraving in one setup.
Grooves resin infilled, panels sanded back, then trimmed from oversize to finished dimension.
A 700mm engraved disc telling Blumlein's story, cut with a fine cutter and infilled to match.
A dark subway is now a lit one, and the thing lighting it is a piece of local history made physical. The lines hold true the full length of both walls, across every joint. The lighting stays serviceable. The artwork reads as one continuous surface rather than a row of panels — which is the whole point of it.
Machined in 2022. Designed by The Decorators for Hillingdon Council as part of the £8.5m Hayes town centre improvements, with sound design by Julian Brown and Richard Green, supported by the EMI Archive Trust and the Blumlein family.
Send us the drawings — we'll tell you how we'd make it buildable.