How do we protect knowledge held by our senior winders and wirers?

Short answer: pick out the few jobs only your veterans do well. Team each veteran with one understudy for a set period. Record the method in photos and brief cards while the understudy learns. Then credit the veteran for how well the understudy does. Carried out at the bench over months, this keeps far more than a one-off documentation drive.

The fuller answer follows, then the questions owners usually raise next. It builds on the knowledge pattern set out on the electrical makers' hub.

Very little of it is secret. It is a pile of small judgements gathered over decades. None of it appears on the drawing, and most of it the veteran no longer notices he knows.

• In the winding hall: how hard to pull conductor round a former's corner, when interlayer paper wants an extra wrap and where duct spacers sit. Also how to bring out tap leads without kinking them, and how a finished coil should feel under the thumb.
• At the wiring bench: the order for wiring a packed cubicle so the last terminations are not boxed in, and how to dress a loom across the door hinge. Also which way ferrules should read, and where a shield's drain wire is earthed.
• On the motor line: how much to tap an end-turn down before it fouls the cover, how tight to lace, and which slot wedges split if forced.
• In memory: which buyer always wants spare terminals left on the strip, and which consultant rejects any loom tied with nylon instead of lacing cord.

Ask every veteran which jobs juniors keep handing back. Put the identical question to the foreman and set the two answers side by side. Then scan the rework tags and the overtime ledger. Jobs that crop up in all three sources make your shortlist. Keep it lean. Three or four jobs per veteran is ample for a start.

Choose one understudy per veteran, preferably someone likely to stay who already pesters people with questions. Set the spell, a quarter for instance, and the jobs covered. Write the pairing onto the shift plan, so a foreman chasing a truck does not break it up.

• Laminated photo cards. The understudy snaps every stage; the veteran rings what matters in marker. One card per job hangs on a hook at the bench.
• Half-minute clips. Footage of the veteran shaping an end-turn or dressing a loom conveys what prose cannot.
• Voice notes in his mother tongue. Some veterans explain far better aloud. The understudy transcribes the gist onto the card.
• Teach-back. The understudy talks the job through for the veteran, who plugs the gaps. That is the true test of a card.
• A slip diary. Every time the veteran corrects the understudy, one line notes what and why. Within weeks it becomes the card's watch-out panel.

Let part of the veteran's recognition ride on the understudy's progress. When somebody other than the veteran signs the understudy off on a job, it counts in the veteran's appraisal and grade. Say so aloud at the Monday huddle. Veterans open up once passing on a knack enlarges their standing instead of shrinking it.

1. 1

   What if the veteran refuses to cooperate?

   Find out what unsettles him. Close to retirement, or straight after a salary row, sharing may feel like giving away his worth. Let him pick the understudy, leave the thorniest job with him and write coaching into his grade.

2. 2

   How many production hours does it swallow?

   A modest daily slot plus ordinary work done shoulder to shoulder. The pair stays on live jobs; the extra minutes go on checking and cards.

3. 3

   Would a thick manual serve better?

   Seldom. Manuals are compiled once and gather dust. Cards hanging at the bench get handled daily and corrected as the shop learns.

4. 4

   What if the understudy quits once trained?

   It does happen. Lower the odds by choosing carefully, tying the understudy's grade to each sign-off and keeping a second understudy in view. The cards remain even if the person goes.

5. 5

   How will we know it has worked?

   See whether the understudy performs the job alone, whether rework on it drops and whether the veteran's overtime eases.

The deep-dive on craft concentrated in a few hands covers the plant-wide fix. For veterans nearing retirement, planning who takes over comes next. The staged winder ladder at transformer works shows how sign-offs can be spaced out.