ABSTRACT
Screens have to be cleaned. This can be a particularly onerous and timeconsuming task, especially in the late Autumn. It may be advantageous to install an oversize area of screening so that the frequency of cleaning is reduced. For the operator of a small hydro-electric scheme to have to rake out the screen in the middle of the night is no fun! Hand-raking is usual on small schemes. Trash rakes are available, but they require manual supervision; at least one firm produces a relatively inexpensive automatic screen-cleaning device, however.
