Calculation of the required rope tensile force

When loads are pulled along a horizontal surface or moved along an inclined surface, the necessary cable force F_S is dependent upon the possible angle of inclination, the weight of the load and the coefficient of friction in relation to the surface. At the same time, one must make a distinction concerning the direction of speed, i.e. whether the load is to be moved upwards (against the incline , +v) or downwards (in the direction of the slope, -v).
A graphic representation of the necessary cable force F_S versus the force due to weight F_G illustrates some fundamental relationships.

Input: Output: α Grad   Rope tensile force at +v m kg   FS = N μ   Rope tensile force at -v     FS = N

When the angle of inclination, the weight and the coefficient of friction (for static, sliding or rolling friction) are pre-defined, the necessary cable force can be calculated for an upward movement (+v) or a downward movement (-v). Example graphics Download » Drawing geometry PDF » Diagram PDF

Calculation of the required rope tensile force for pulling of loads and moving of loads on inclined planes

Drawing geometry upwards

Drawing geometry downwards