Comment by Sesse__

You can build fiber basically arbitrarily solid. A normal patch cable won't be that solid, but the more rugged trunk cables is something like (just pulling out of a data sheet for something I used a while back):

  * Outer diameter: 6mm
  * Max tensile load: 900 N
  * Crush resistance: 750 N / 10 cm
  * Max proof stress: >= 0,69 GPa

To be clear, this is not specially rugged cable by any means. This is just a normal G12 cable for general use. You can get stuff that's much more solid. It's certainly much lighter than the equivalent SDI copper cable.