I think this might be something that
@Paul AC would have some information on?
We’ve actually had a thread related to this kind of thing fairly recently:
I particularly remember reading a comment from a senior BR engineer involved in the cl. 74 project, along the lines of 'never again' as far as doing that sort of major conversion. mods note - split from here I seem to remember reading that a contributing factor in the lack of reliability was...
www.railforums.co.uk
Thankyou for that, it’s always interesting to to find things out around the time class 89 was being designed and built.
The microprocessor rack was on PCB’s I believe but I was not involved with that side so much.
The Electronics control system was what I was involved in.
It was always going to be a prototype and a one off. No PCB’s were made for the electronics control system system and I had to hand build and wire wrap every single connection on all the boards ( I can’t recall how many there were). I used Vero boards and soldered integrated circuit wire wrap pin mounts for the chips.. and single pins for the resistors and capacitor and diodes etc. I made layout drawings for each board so locating each component would be possible for fault finding.. the wiring diagram drawings I used to mark off what connections I had done one by one.
The comments about the environment these boards were expected to operate in has always crossed my mind, and if any were made into proper PCB’s (which I doubt because of complexity and cost)… hence my interest in going to see for myself, as it’s over 40 years since I made the control system electronics.
Thankyou in advance if anyone knows anything more.