I`m sure the boaters amongst our readers know how a staircase flight works but me and Jaq have many friends and family back home who have no clue. Some of our readers might be new boaters who will enjoy the post. So experienced boaters are excused reading this post; feel free to do the washing up or carry on knitting.
Bunbury staircase locks are the first locks after leaving Nantwich on our journey to Chester. This staircase is made up of two locks and raises/lowers the Shropshire Union canal 15 feet, 7 inches.
The difference in canal levels from the top lock in picture 1 to the bottom lock in picture 2 is as I mentioned, 15 feet, 7 inches and it will take two courses of action for the boats to swap places. With all gates shut the water is released from the top lock (Pic 1) into the bottom lock (pic 2). This will make the water level in both chambers equal.
So now on the left is the top lock (picture 1). The boat has come half way on it`s climb and will now let water in to raise it the rest of the way. The boat on the right is in the bottom lock as in picture 2, and will now let water out, lowering it down.
On the left two boats have come down in the top lock together and one boat has come up on its own. The gates are being opened between the locks. As in picture 3 above, the boats must now swap places so it is time to do the "Bunbury Shuffle". On the right above, one boat going down moves forward and into the vacant space next to the boat going up. The single boat facing us comes into the vacated
space, below left. The last boat then
moves forward, below right. The first boat in has moved across the lock to make this manoeuvre easier for the last boat in. The gates will now close and the two locks will be filled or emptied to take the boats to the upper or lower sections of the canal.