Wednesday 8 May 2013

4 Street Elbows

4 Street Elbows

Saul Bobroff

Saul Bobroff. Puzzle available commercially from Eureka Puzzles for US$85.

Type & Classification
Impossible Object

6.2 cm (Length) x 6.2 cm (Width) x 2.2 cm (Height).

Materials & Construction
All four pieces of plumbing street elbows made of iron. Quality of construction is very good and the puzzle is coated with a sealant to prevent rusting. Wooden display stand included.

The 4 Street Elbows was Saul Bobroff's Exchange Puzzle during IPP28 held in Prague, Czech Republic in August 2008.


The 4 Street Elbows is in reality an "impossible object". I had come by this "puzzle" through a puzzle exchange with Saul; my Ball In Cylinder No.1 for his Street Elbows. Consisting of four standard looking plumbing elbows, they are joined (and held together) by the screw threads of each elbow. Meaning to say that the pieces have not been joined by welding, glueing, force-fitting etc. When it first arrived, I was wondering how to solve it and whether in fact it was meant to be solved.

Like all impossible objects, it looks unsolvable. I did a check with Saul and he informed me that the puzzle is "solved already". I took it to mean that its really not meant to be solved in any way. Personally I am not sure if I want to try to dis-assemble looks like some heavy duty tool might be needed for this task but I won't take the risk. I might just break something in the process.

Difficulty Level
Saul also mentioned that there is only one person who has removed and the elbows and put everything back into the solved state. Now I wonder who that person might be?

Not a puzzle for solving by any means, but something to be admired for its uniqueness and physical incredibility. Definitely worth collecting though.

Also by Saul Bobroff - "Too-Tite"...Impossible Object. Tennis ball in a bottle.
A gift from Saul, thank you very much.


  1. Fascinating object! I would love to see how Saul assembled it. It just melts my mind even thinking about it :P

  2. Yes, me too. I think only one other person (apart from Saul and the guy who solved it) knows the solution...and that's Jeff Chiou. See his blogpost at:-

  3. $85 seems a lot for a puzzle that is "solved already" my guess is that one of the threaded joints only fits inside the pipe by a couple of MM's....maybe!!!!

  4. David, that is the price Eureka Puzzles is charging. Their IPP items are not exactly cheap.

  5. Can be made easily using Klien Bottle Elbows, but these are rather expensive. Using real plumbing elbows is more difficult, but at least does not require 4D components.

  6. Two methods. Screw 2 sets of 2 pipes together, screw one of the sides of the 2 sets together. When it is to tight to move any more, back it off 2 turn or two and heat the male side of the pipes until red hot. Using a wooden mallet and a vice, hammer the last piece into the last piece until it is where you want it. Let it cool down. Have fun.

    Second method: Same as above except on the last part inserted, grind down the threads on that piece about 3/4 the way up from the bottom of the thread. Leave the top 14" or so threaded. One again use you handy vise and beat the last part into the male piece until the first few bottom threads catch hold and lock into place. Abracadabra, you have your very own.

    You can also screw in 2 sets of 2 pipes to each other and then do the same thread grinding job on both male parts and then once again beat the parts into place until they lock together. I can reveal how to make any of the others if you like. Sorry about my displayed name. It is from back when I was into sports. Helped irritate the other team. :-)

  7. Could only guess that you would need to freeze the structure using dry ice to shrink the elbow enough to loosen the hold of the threads maby?