Apologies for being late with the teaser answer tonight, I've had a wee problem with the old 'puter. ![]()
So anyway let's cut right to the chase...
Having shown you this

Then this

And this

Coupled to various references to water, boats, wind-ups, etc.... I kind of thought maybe I'd pushed you all in the right direction.
Happy was on the right track when she said a lock gate... and Spicy was also on track with canal lock... a prize to both these lovely ladies. 
It's a sluice gate mechanism... a wind-up thing! 
For letting water through a dock gate... a lock gate... 
Congratulations girls... prize draw is open. ![]()
![]()













