…looking down on the trains running in and out of Shrewsbury station, from three of its now-famous signal boxes. Shrewsbury is an island of mechanical signalling, a survivor because of its complexity, among other things. It came within a hair’s breadth of resignalling perhaps 30 years ago (what would we have been left with? Fewer platforms and less track, I suspect – and insufficient capacity for today’s intensive services). Its fame? Primarily because, for the last few years, Severn Bridge Junction, with its 180-lever frame, has been the biggest mechanical signalbox in the world. Wow! More photos will follow in a day or two, on Geoff’s Rail Diaries; in the meantime, a taster…