In the early part of my career I worked for Daval in Perivale , Middx. They made wire recorders for aircraft . One was featured on Tomorrow's World and nick named the Red Egg, it was used on Concorde. An early version had 2 spools and the wire was transferred between the two, that auto reversed. It had a very neat double helix wire guide to ensure the wire was laid out on the receiving spool in an orderly manner , this also that reversed at the end of each travel without snatching. It was nightmare reading the data back when the wire broke. It was also getting difficult to source the special wire in the late 70s.
Later on worked on recorders used to record maintainence and trials data on Torpedoes, PIGs (pipeline inspection gear) and the F18 for the US Navy aircraft . The real challenge was to compress the data enough to fit on these recorders as they had limited storage capabilities. The crash recorders were nicknamed the "on sh@t recorder" as it was normally the last words that were recorded in the event of an accident. I visited AAIB and US equivalent a number of times, it used to send shivers down my spine when i saw the wreckage reassembled.