Basingstoke Canal

Which I walked along part of today with my friend Louise. 16532 steps so far today (did not do the circuit in addition!) A little beyond this lock is a boat shed with 2 notices pointing in opposite directions.
Notice 1= Greywell Tunnel via Fleet and Odiham, 23 locks 29 miles
Notice 2: Ripon Yorkshire via Oxford and Leicester. 173 locks, 386 miles

What i would also like to know from you canal boat experts is what the bit of kit shown in my extras was used for. Clearly it turned........ Any clues please?