The Dragon Lock

More commonly know as the Chinese Rings puzzle

The objective is to remove the shuttle from the rings.

It was very popular during the Sung Dynasty ( 960 – 1279 ) were it was used as a lock with almost every Chinese family.

Although it is most often thought of as a disentanglement puzzle, it is probably better classified as a sequential movement puzzle, for this is the key to it’s solution, often classified as very difficult the principle is straight forward

The puzzle can found in many different forms some more elaborate than others and can be expanded in difficulty by adding rings.

Every time an additional ring is added it doubles the number of moves required to complete the puzzle. A simple five ring puzzle, requires sixteen moves, While the seven ring one pictured here would require 64 moves.

The solution :-

The thing that makes this difficult to work out at first is that the first part of the problem is often over looked and that is it works in reverse, by that I mean you have to disassemble it from the back to the front and this is what stumps most people.

The moves are really simple but you must remember the rules

You Can only remove the ring directly behind the first ring.

So to remove the second ring the first ring has to be on the shuttle, to remove the third ring the second one has to be there and so on.

So lets take a five ring lock it goes like this

Remove ring 1 this now makes ring 2 the first ring

Remove ring 3 as it is now in second place

Now you have to replace ring 1 so that ring 2 can now be removed and remove ring 1 again

You now have rings 4 and 5 left on the lock but as 4 is now the first ring 5 can be removed.

Now replace ring 1 this allows for ring 2 to be replaced

Remove ring 1 making ring 2 first place allowing for ring 3 to be replaced.

Replace ring 1 and remove ring 2 so that you are left with ring 3 and 4 in first and second place.

I’m sure by now you get the picture in order to remove the shuttle the rings have to be removed 5,4,3,2,1 and re assembly is the opposite 1,2,3,4,5