August 11th – This is something I knew about, but had never seen in use. It’s a bit geeky, but I find it a fascinating demonstration of simple solutions being best.

As New Street Station is gradually turd-polished and sprinkled with cheap glitter, platforms are periodically closed to the public. At the moment it’s the turn of platform 3.

When the platform is closed, so is the adjacent track so that work can be undertaken in safety. The track is blocked, the overhead wires are grounded and these detonators are placed on the line.

Should a train get down here, the yellow disc, which contains a small but effective explosive charge, will be crushed by the wheels, activating the explosive. This makes a sound like a gunshot, alerting nearby workers and the driver.

This technology has been in use for decades, but I didn’t know it was still employed today.