Lifts without a tensioning device

Abstract

In Barcelona I spoke about the work I had been doing with the Polytechnic di Torino on the tensioning devices; afterwards, the theoretical work was developed and we made a series of tests with a device able to measure the tension of the rope in the drive station of a moving 12-passenger gondola lift. As further development, I am proposing now a series of cases where a circulating lift can work in a simpler and safer way without a tensioning device, often without any increase in the rope diameter. One of the reasons why the classic circulating-multi-tower lifts had a tensioning device was the line calculation: years ago it was quite impossible to perform such a calculation by hand! Now we have good and affordable computer programs that can solve this problem: these programs make possible to build lifts without tensioning device when it can be useful, or to use an intelligent variable-tension device, if this solution offers advantages. We need some norms for these new designs, so I suggest some issues emerging from the test calculations, which I did on lift lines with no tensioning device. In many countries, the approval of new concepts lift design by the Surveying Authorities needs Norms. A big obstacle in developing Norms and methods of calculation is the lack of experiments and the high cost of them; I propose a new approach to the experiments on the rope configuration, using a mixture of model testing and computer simulation. The computer simulation is calibrated using a model of lift that can be configured in many different ways; this low-cost model is built using standard materials and it is really easy to take measures and data.