Wow, where to start.
I'd chosen the technical forum for a technical discussion. Instead every participant bar one has commented on terminology. Thank you OK465, you are correct. I should have referred to them as leading edge devices.
MarkerInbound, thank you for your contribution. 3000 psi is a measure of pressure not force. Additionally, the leading edge devices are generally powered by a torque tube running behind the fixed leading edge. This can be powered by a hydraulic motor, usually in the left wing root, which will have 3000 psi powering it. But how much power does the hydraulic motor put out?
There are publications out there that refer to Handley Page Slats as being unpowered leading edge devices. This is what I have learnt. I am confronted with Boeing SRM's that refer to beams as chords, straps as chords, stringers as chords. Yet I learnt a chord is a measurement of distance between the leading and trailing edges of a wing. I suppose this is another example of the golden rule, he that hath the gold maketh the rules.
I think that Lachmann also referred to his leading edge devices as slats, (quick Jeeves look up Lachmann).
My comment "long live Fredrick Handley Page" should have read "long live the memory of Frederick Handley Page". An independant thinker ostracised from British aerospace.
After all that, does anyone know the sort of forces invovled in extending the leading edge devices at say 160 knots?