Maths challenge…..

[RunAgroundHard]

... assumptions about how the line will stack on the drum. ...

This is why Lebus grooving was developed on drums, it makes the calculation of wraps precise because the wrap geometry gets controlled, including subsequent layers. Furling drums are quite simple and Lebus grooving would be an additional expense in the manufacture. It doesn't prevent line jamming / jumping from high velocity subject to high negative acceleration, but it does make the wrap predictable at controlled velocities. The main feature is that it does away with line spoolers e.g. on crane drums and drawworks.

On my own furler, after the seasons first good blow, I have to readjust the line wraps to get the 3 wraps when fully furled. A pain but doable.

 

[AntarcticPilot]

This is why Lebus grooving was developed on drums, it makes the calculation of wraps precise because the wrap geometry gets controlled, including subsequent layers. Furling drums are quite simple and Lebus grooving would be an additional expense in the manufacture. It doesn't prevent line jamming / jumping from high velocity subject to high negative acceleration, but it does make the wrap predictable at controlled velocities. The main feature is that it does away with line spoolers e.g. on crane drums and drawworks.

On my own furler, after the seasons first good blow, I have to readjust the line wraps to get the 3 wraps when fully furled. A pain but doable.

Also, what works for wire rope may not work so well on deformable fibre ropes.