An early version of the Petřín ropeway in Prague used to contain tanks in both cars. The upper one would be filled with sewage collected rainwater from the city’s hilltop quarter and the energy of the descent was used to pull the other car up. Additionally, the way up cost twice as much so there was an incentive to ascend on foot, which was about as fast despite the incline.
I know, this one is shorter and has mechanical brakes. Not as great but I imagine the Czech one, one of the largest in Europe, has very few English-language sources that could have pointed it out to him. I don’t know whether the Claughton one cannot be ridden or Tom is just squeamish about safety (see description) but the Černý Důl one definitely can, that’s how they do routine inspections.