Desiccation about all part of spiral escalator

2. Outer tube

   Fig (iii): SolidWorks® view of the a outer tubing cylinder
   
   In our design we have to cylinder. Outer cylinder it is a fix cylinder whish have opposite helixes than the inner cylinder. The outer cylinder made form ductile iron because its mush safer than cast iron. And also it’s 5.6 meters. This is the distant between to floor.