After a quick look around I headed back to the main line and walked up the locks. The BWB mainatance boats Cornwall, Yarrow and Clitheroe II were at the locks fitting new gates.
By the small toll house at 4th Lock Bridge I tried to work out how the system worked for towing boats with no towpath under the bridge. There is a metal hook on the bridge which was obviously used and the bollards were well worn as were the stone work a the top of the bridge. The horse could cross the road and pull the boat out of the lock. The rope would go from the boat, around the hook, back to the bollard and then to the horse. At some point the rope would have to be detatched from the boat.
The buildings of Lock Farm are dated 1727, that is before the canal was started in the 1770s