> Worse, they're on vertical surfaces in the shafts, where maintenance will be difficult. Maybe - but movement on two axes lets you get creative with your tool

> Worse, they're on vertical surfaces in the shafts, where maintenance will be difficult. Maybe - but movement on two axes lets you get creative with your tools. You could for instance store a "maintenance car" with special fittings that expose the shaft mechanisms. The car could be introduced into the system as needed and removed when it would just be in the way.