Theoretical RADS Ratio

RADS Theoretical Ratio:

 

RADS is actually a 'Gun Tackle' where the climber is both the weight AND the pulling power on the lift line.

 

So, by the weight balance method (ignoring friction); the climber only has to pull 1/3 the weight which results in a theoretical {frictionless} 3:1 mechanical advantage.

 

By the line measurement method; Line pulled passed the climber is 3 times the lift of the climber. Therefore, the climber experiences 1/3 the movement relative to the line moved by the climber - again, a 3:1 mechanical advantage.

 

Of course, actual {real world} mechanical advantage has to include friction which can be quite significant and greatly reduce the theoretical numbers we are discussing here.

 

Done