Via http://haylepump.org.uk/documents/haylepump117final.pdf

Sluicing returns

New sluice gates have been fitted to Carnsew Basin in Hayle as part of the plans to resume a sluicing regime, part of the South Quay development by ING.

The sluice pools and sluice gates in Hayle traditionally played a major part in deepening and straightening the navigation channel from the bay into the port of Hayle, and maintained that depth to allow bigger ships and more commerce for the port. This in turn increased the success and wealth of the rival Cornish Copper Company and Harveys of Hayle, which led to greater investment and development of technology and business which helped Hayle play its part in the Industrial Revolution.

The waterways and sluice pools and systems are a large part of the “Overall Universal Value” of Hayle to the World Heritage Area status. It is hoped that sluicing will reduce or replace any need to dredge and sell sand from Hayle.

The idea is that the gates open freely with the pressure of the incoming tide, then swing shut as the tide turns to go out, keeping the water in. Then at the correct time, the smallergates are winched open to allow a strong force of water to sweep sand and sediment out into the bay. Originally hand winched by local harbour employees, the new gates with have the facility to attach a hydraulic device.

Graham Coad