The Lockkeeper’s Ledger

A two-day timetable for the Wendle Navigation
Showing:
Day 1 13:00
Boats climb this hillside canal through locks — water lifts with gates at both ends — and three keepers must be at a lock for every operation. Press Play to watch the plan run.

Timetable (Gantt chart)

Click the chart to jump to a time. Click a bar to follow that boat; click empty space to clear.

Something went wrong on the canal?

Close a lock for a while, or hold a boat back at its start, then re-plan. The page re-solves the schedule right here, in your browser, using the same solver as the command line (with a shorter search), and shows what changed.

Close a lock
Delay a boat’s release

    How a canal lock works

    The rules of this canal, briefly

    • A boat going up passes locks from+1 … to, each with an up operation (chamber fills from the pool above). Going down: down operations (chamber empties into the pool below).
    • A chamber holds two slots: two narrowboats or one barge. All boats in one operation go the same way.
    • An operation takes fill/empty time, plus time to enter and leave if any boat is aboard. It must sit inside opening hours and clear of maintenance closures.
    • A keeper must stand at the lock for the whole operation; walking takes time.
    • Each fill takes water out of the pool above at its start; a pool may never fall below its minimum. A feeder stream tops up the summit.

    How the plan is scored

    Lateness of a boat = minutes after its deadline when it leaves its last lock. Weighted lateness = ∑ priority × lateness (priority 3 is the doctor’s launch, 1 a holiday boat). Lower is better; ties are broken by total water drawn. An invalid schedule scores nothing, so the solver and the page both re-check every rule.

    Where the numbers come from

    Scores, water levels, waiting reasons and the disruption re-plans are all computed in this page by the same engine (solve.js) that wrote the schedule — nothing about the delays is typed in by hand.