Field note · 12 March 2026

When the timestamps on a feeder trip do not agree

A substation clock, a historian, and a rewritten log page can each tell a different minute. The briefing should keep the disagreement, not average it.

A feeder trip looks simple in conversation: the line died, the crew switched, the town came back. On paper it is usually three times. The protection relay stamps one minute. The historian in the control room stamps another. The logbook, written in a calmer hand after dawn, stamps a third.

Averaging those minutes produces a time that nobody actually recorded. It also hides the only interesting fact — that someone changed a clock, or that the historian was still catching up after a restart, or that the log page is a copy.

Name the source on the drawing

When we draw a restoration ladder we print the source next to the time: “relay 51, bay 4”, “historian, Batumi desk”, “logbook p. 18, original”. If the original page is in a locker, we say so. A rewritten page is not a crime; it is a second document.

What operators can do before we arrive

Photograph the log page before anyone copies it neatly. Export the protection flags with their own clock, not a screenshot of a summary. If a clock was changed after maintenance, write that on the maintenance sheet the same week, not during the investigation.

Railway possessions teach the same lesson with kilometre posts: three offices, three descriptions, one stretch of track. Electricity does it with minutes. The cure is the same. Keep the disagreement on the page until a document proves which clock was wrong.