The truck-mounted CPT rig arrives with a 20-tonne reaction mass and a cylindrical steel cone just 35.7 mm across. That slim probe is the heart of the operation. In Swansea, where glacial till and weathered Coal Measures alternate inside a few hundred metres, you need a machine that reads the ground in real time. The cone pushes down at a steady 20 mm per second while sensors measure tip resistance, sleeve friction, and dynamic pore pressure. Every centimetre produces a data point. No drilling, no cuttings, no delay. For builders working the SA1 waterfront or the upland clays near Killay, this means one thing: you know what is under the slab before the concrete truck arrives. The information feeds directly into Eurocode 7 designs and helps avoid the kind of over-excavation that kills budgets on brownfield sites. When we combine CPT data with lab-based triaxial testing, clients get drained and undrained strength parameters that let them trim foundation sizes confidently.
In Swansea's glacial till, a CPT rig can identify a 100 mm sand lens at 6 metres — the kind of detail that changes an entire dewatering plan.
