Tony I'm not trying to hijack this thread but I would be interested as to what additional training for industrial work was done by the guys that have replied.
For me when I joined the railway signalling department I had already done my full apprenticeship in electrical installation gaining C&G 236 parts A, B & C plus the AM2. Then it was basically a second apprenticeship in railway signalling which could last anywhere between 4 & 6 years to make it to Technician Officer grade. Luckily enough I managed it in 4 but it was a tough old slog. This training consisted of 3 months block per year in the railway signalling school in York with the remaining nine months being spent being closely mentored in the field. At the end of each year there was a 5 day written / practical assessment that moved you up a grade if you passed.