Wendle Navigation · nine locks up a hillside · three keepers · forty boats · two days
In one breath: boats climb a hillside canal through nine locks — water-filled chambers that lift or lower a boat between two level stretches of canal (pools). Every lift uses water and needs a keeper at the lock; nothing works at night. Press ▶ Play to watch the schedule, then scroll for the timeline, why each boat waited, and a what-if planner.
New to canals? What am I looking at? (30 seconds)
1. Enter. A boat sails into the lock chamber while it is level with the lower pool. Gates close behind it.2. Lift. Water is let into the chamber — here it is taken from the pool above — and the boat rises to the upper level.3. Leave. The upper gate opens and the boat sails on. Going down is the same in reverse: the chamber empties into the pool below.
Pools
are the level stretches of canal (P0 the river at the bottom, P9 the summit). A lock joins two neighbours.
Water
is the scarce thing: every lift takes a chamberful from the pool above and a pool may never drop below its minimum. Only a small stream feeds the summit, so water trickles down as chambers are emptied. Carrying two narrowboats at once halves the water and time used.
Keepers
work the locks by hand: one keeper per operation, present the whole time, and they need time to walk the towpath between locks.
Closed
at night (22:00–06:00) and during maintenance. Boats can still glide across a pool at night.
Late
means finishing after the boat's deadline. Each minute of lateness costs the boat's priority (a doctor's launch = 3, a holiday boat = 1).
The canal, animated
Day 1 06:00
Gantt chart — every operation
Why boats were delayed
Every waiting time below is worked out by replaying the schedule minute by minute and asking what physically stopped the lock from working sooner. Nothing here is hand-written.
Click a row to see where and why that boat waited; “Watch” jumps the animation there.
Disruption mode — what if?
Close a lock for a while, or hold a boat back, then re-plan. The page re-solves in your browser with the same solver code that produced the schedule (a shorter search) and shows what changed.