The autumn rope scan, and why we close for eight weeks
Every October the line shuts and a magnetic head runs the whole 4,180 metres of haul rope looking for broken wires you cannot see from outside.
The line closes on 01 October and does not carry a passenger again until 01 December. Two months is a long closure for a cableway and people ask about it every year, so: this is what happens in it.
The scan
A magnetic head is clamped around the haul rope and the rope is driven through it at walking pace, end to end, both directions. The head reads the rope’s magnetic flux; a broken wire inside the strand — which nothing on the outside would show you — changes that flux and appears on the trace as a spike.
The rope is 46 mm, six-strand, full-locked, and it is 4,180 metres long. A full scan takes four days and produces a chart the length of a corridor. It is read by an inspector who does not work for us, which is the only arrangement worth having.
The rest of the overhaul
The sheave train comes apart tower by tower — every wheel off, every liner gauged, every bearing spun by hand. The grips are pull-tested to destruction on a rolling sample, and the two that fail earliest set the replacement schedule for the following season.
None of that can be done at night between hauls. It is the reason the autumn column of the timetable says “Closed” instead of “Reduced”.