The 'boil' explained

THE word 'boil' used in the trust's stoppage notice concerning the Calder & Hebble has created comments, but here's the explanation.

The boil is the effect seen when a top lock gate fails at or near the bottom, or where the cill has failed under the gate so that water 'boils' up from the gap between the gate and the cill.

This probably means the notice has been written by an operative familiar with how gates fail, and would probably be a good sign—if the lock was going to be repaired!

Giles Williams
Inland Waterway Skipper