North basin ran on a whiteboard and two radios for eleven years. It worked, in the sense that the ships left. What it cost was the first ninety minutes of every morning, which went to establishing what had actually happened overnight before anyone could decide what to do about it.

The first thing that changed was not the planning. It was that the overnight events — a late barge, a crane held for inspection, a crew short — arrived as rows instead of as rumours. By the time the gate opened, the argument about what was true had already been settled by the record.

The planning changed second, and more slowly. Crews trusted the board about six weeks in, which is roughly when the third or fourth reshuffle propagated correctly without anyone re-keying it. After that the whiteboard stayed up for a month out of superstition, then came down.