This is the new system for emergency communications? TfL just finished up an upgrade on that in 2021. That upgrade was built by Thales.[1] That system is purely for operational use, and is not cell phone compatible. It's compatible with the gear cops and fire brigades use. Is it being replaced?

As late as 2018, the classic century-old system, with two bare wires on insulators on the tunnel walls, was still maintained.[2] Clipping a telephone handset to the two wires would connect to a dispatcher, and the wires were placed so that reaching out of the driver's cab to do this was possible. In addition, squeezing the wires together by hand would trip a relay and cut traction power. Is that still operational? The 2011 replacement was ISDN.

[1] https://www.thalesgroup.com/en/news-centre/press-releases/th...

[2] https://www.railengineer.co.uk/communications-on-the-central...