This was Brian Young’s Exchange Puzzle at the Gold Coast IPP in 2007 – modelled after the distinctive golden coloured parking meters installed along the Gold Coast in the 1960’s. There’s a lovely story on Brian’s web site about bikini-clad ladies causing a bit of a stir feeding expired meters along the Gold Cost to stop tourists from getting parking fines. For some reason when Brian used a suitably attired young lady as his assistant to hand out puzzles at the exchange, it went down rather well.
As a sequential discovery puzzle, it looks pretty unusual – you don’t generally come across puzzles shaped like parking meters very often for one thing, and for another, the object is to get the money (a 10 cent piece in this case) into the puzzle ... the coin projects out of a slot a bit and it clearly won’t just get pushed in, so you need to explore a bit.
There’s a reasonably obvious place to start: there are a couple of tell-tale signs on the sides of some moving blocks, but they seem stuck pretty solid at first ... so you explore a few more things – and at this point it might be wise to point out to any rather ham-fisted wannabe puzzlers that the base and stand do not come apart and breaking them off will not help you solve the puzzle ... and yes, I’ve had to warn one or two folks – some of my mates can be way more enthusiastic than clever ... and I guess that probably says a bit about me as well!
Right, so the base won’t help, and unless you have enormous fingernails, you’re not going to prise out the pins holding the dial in place (and that wouldn’t be a good idea either) – so you go back to working on the sides – and applying a little brain power will release a couple of blocks – but that coin is still stuck in place and a lot of fiddling, and using what you’ve found will get you past the next hurdle – which will let you put in the coin into the meter and then put it all back together again.
[And then you can reverse the process to reset the puzzle again ... because handing a parking meter to the next person and asking them to take the coin out of it, would just be wrong!]
The mechanism itself isn’t overly complicated, but it’s beautifully disguised and very nicely executed ... and Brian’s added a couple of his favourite little tricks to slow you down along the way. It’s one of those puzzles that puts a smile on your face.