Hello,

Wondering if this topic has been broached before or if anyone knows the correct equations for this problem.

I'm designing a transmission line pulling unit and looking to fabricate a drum that will hold the wire rope that will pull the transmission line through the towers.

Curious on the stresses that will be incurred on the drum, drum barrel, and drum flanges as the number of wraps increase and the line tension increases during the pulling operation.

I found this equation, but wanted to ask around and see if anybody had some expertise in this field.

Radial pressure on the core P=2T/Dd. "T" is line tension, "D" is the diameter of the drum and "d" is the wire rope diameter

The equation is layer sensitive; the next successive layer would change the diameter of the drum core by D'=D+2d.

laying a layer of wire rope of diameter "d" on the nude drum core of diameter "D" would increase the second layer pressure to P'=2T/[(D+2d)d]

Also found this equation:
Minimum Thickness of Drum Required as per DNV Standard = Rope Factor x (Ultimate Pulling Force x 1.1)/ (0.85x Yield Strength of Drum)x Pitch of the groove on drum.


Considering rope factor = 1.75 for more than one layers.