The narrow entrance to the inner harbour at Amlwch could be closed by the placing of 13 baulks of timber to create a gate. Ship masters would be asked to provide crewmembers to help lift the baulks into grooves in the quayside. The winches that provided assistance are now all that survive of this vital protection measure from northerly swells.

Sources include:
Amlwch Industrial Heritage Trust, Porth Amlwch Heritage Trail leaflet

RCAHMW, August 2012.