Canwick Hall, 07. Tipper Device
A horizontal metal channel was balanced over the centre of the filter bed cover on two bearings or tipper devices (shown here).
The horizontal channel was divided longitudinally in two.
When the liquid effluent from the tank had filled one half of the channel its weight caused the channel to tip to one side and drop the liquid on that side of the cover.
The action of tipping brought the other half of the channel into position to be filled, and so, in due course, sewage was tipped over the other side of the filter bed cover.
The cover, made of corrugated iron, had regular perforations to distribute the liquid sewage across the filter bed.
Only very small fragments of the cover have survived.