topically scaffolding are in bucks of 6 feet toprails are at 42 inches off the platformon of each leval which also has a toerail at platform leval to pervent something from slideing off a midrail between the two.This system of 3 rails continues on every leval regardless of how high the scaffelding is bult. First platform is at 6 ft. first toprail is 9ft 6 in. Workers must be tied off anytime there over 6 feet.
safety reasons...to work platform...if your curious about fall protection issues and requirements...the lowest part of your body is your fall height...