I have always wanted to build one of these wonderful spiral layouts but never had anywhere near enough Meccano to make such a thing. The nice feature of course is it is endless so just runs and runs, great for shows.  If someone could come up with enough Meccano I would be happy to help build one for a show. Pictures below are of a MarklinSpiral layout Meccano 2 Spiral layout Meccano 1 Spiral layout Meccano 3 Spiral layout Meccano 4 Spiral layout Meccano set up.