How do we manage night shifts on automatic machines?

Half past three on a Tuesday morning. A multi-station bolt former is still thumping away, along with two thread rollers, a row of cam automats and a centreless grinder. Four operators cover all of it. One notices head height creeping on the former. He is unsure whether he may touch the set-up. The setter went home at ten and the supervisor's phone rings out. So he lets it run. When the day inspector reaches the bin, the whole night's output is suspect.

Most night trouble in component plants has that shape. The machines are automatic; the decisions are not. The fix is to settle in daylight what the night crew may decide, say who holds authority, and make the morning read what happened. Units on our group page for component plants run headers, rollers, sliding-head lathes and grinders around the clock, so one routine fits most of them.

Every night needs one person running the floor. Usually the role goes to a senior operator or setter on a lead allowance rather than a supervisor. Write down the lead's powers: stop any machine, quarantine a bin, ring the on-call setter, and move an operator between machines. Chalk the lead's name up at clock-in. If the lead is absent, the board names a stand-in before the day office empties.

The authority has to be real. If a lead halts a header and the production head grumbles about lost pieces next morning, no lead will halt one again. Thank the stop in the meeting first. Only then discuss whether it was needed.

Machine group and the machine numbers it covers.
Operator may adjust: feed length inside the marked range, coolant flow, a coil or bar change, a worn insert swapped from the labelled tray.
Call the night lead: a dimension creeping towards its limit on two patrol readings running, an odd knock or squeal, a broken punch, a gauge that will not zero.
Stop and quarantine the bin: any part outside limits, a mixed part in the chute, a lap or crack on a head, a guard or interlock fault.
Lead rings the on-call setter: whenever a restart needs a set-up change above the operator's grade.
Phone list: night lead, on-call setter, maintenance fitter, and whoever can authorise scrapping a lot.
Patrol interval, the gauges to use, and the sheet where readings go.

Draft each card with the day setter who knows that group. Keep it to one laminated side, in the language the night crew reads, and fix it to the machine guard. The card does two jobs. It replaces guessing with a rule. It also shields the operator who stops a machine from being blamed for the lost count.

1. 1

   Overlap the shifts briefly

   Outgoing and relieving operators meet at the machine. A short overlap beats a note left on a desk.

2. 2

   Fill a one-page handover note

   Part and lot running, last patrol reading, tool life left, any offset made, anything waiting for a setter.

3. 3

   Tag every bin

   Good, suspect and rework bins are labelled at the change of crew, so nothing travels forward untagged.

4. 4

   Read the night log each morning

   Production, quality and the day setters go through stops, calls and rejects from the night. Each repeat fault gets a name beside it and a target day.

Our shift changeover note guide covers the note for any plant. On automatic machines the line that matters most is tool life. A punch, rolling die or grinding wheel with little life left should never pass to the night crew without a decision about who changes it, and when.

Night rejects hide inside monthly totals. Split rejects and rework by shift and section every week. If nights on the thread rollers reject more than days, the cause may be a lapsed gauge routine, a missing setter, or a part only the day setter runs well. Read the patrol sheets before blaming anyone. Blank rows between three and five often show when alertness sagged.

Nights turn sour when they become the dumping ground for newcomers, latecomers and the out-of-favour. Capable operators then dodge them, and the weakest hands run the machines at the hardest hour. Publish the rota weeks ahead and rotate on a fixed pattern. Add a night allowance and explain plainly what it covers. Keep at least one Grade C operator or setter on every night. Count time as night lead towards promotion to setter, as the operator grading ladder suggests.

• Do we need a setter on every night? Not always. A strong lead plus an on-call setter who picks up covers most units. Frequent calls are the sign to roster one.
• How many machines can one operator mind? As many as a full patrol round allows. Time one round of gauging and plan from that, not from a machine count.
• What about the hours before dawn? Alertness dips then. Schedule a patrol round, a short break and a walk by the lead in that window.
• Can a fresh recruit begin on nights? Not during the first weeks. Let recruits learn on days, with setters and quality nearby, before any night rota.

Pick one machine group, write its card this week, make someone the lead for each night, and read the log on Monday. The deeper note on thin senior cover after dark sets out what an unmanaged night costs in rework and returns.