On Wednesday, 27 May 2020 17:13:45 UTC+1, Dave Liquorice wrote:
I think I need a new one - but it got me thinking - is there an optimum
bristle length - and why?
I think this could make a good doctoral thesis subject.


Been done, at least in part.

https://ethos.bl.uk/OrderDetails.do?...l.ethos.442887
Dynamics and performance of oscillatory gutter brushes for street sweeping


http://epubs.surrey.ac.uk/844307/
A general theory for channel brush design for street sweeping.

John Chew at Surrey seems to be the man to go to for brushes and brush seals

Owain