Cable Carousel

[BEMPE16524]

Hello Everyone,

I'm trying to figure out the acting force on the the wall/fence of a cable carousel as in following image:

I tried to look for a design standard but so far I couldn't find one. So, here is my assumption:

n : vertical number of cable layers
nh : number of cable turns on each layer
M : total cable mass on each turn
Mnh : Mass of cable on each horizontal layer, i.e; M1, M2, M3, etc...
g : gravity

I know that there will be a cable transition between each layer. So, i'm assuming that 'nh' for all layers will be the same (the image above is simplified).

F1 = 0 N
F2 = 1 x (M1+M2+M3+M4+M6+M6)/2 x g
F3 = 2 x (M1+M2+M3+M4+M6+M6)/2 x g
F4 = 3 x (M1+M2+M3+M4+M6+M6)/2 x g
F5 = 4 x (M1+M2+M3+M4+M6+M6)/2 x g
F6 = 5 x (M1+M2+M3+M4+M6+M6)/2 x g

Fn = (n-1) x M/2 x g

Note:
1. I divided total mass, M by 2 as I'm assuming external and internal wall will share the force together.
2. There will be a safety factor to be applied too base on standard offshore structures/machineries.

Is there any other things I have to take into consideration?

R.Efendy

 

[MintJulep]

How have you made the downward force of gravity act horizontally?

I see no basis at all for assuming that the ID and OD would equally share load.

Radial forces will be produced by tension due to winding and the cable's desire to straighten itself.

 

[robyengIT]

are you sure that the cable is in touch with internal/external wall ?? first (and similar layers) of your sketch is/are impossible to me

 

[TugboatEng]

The horizontal force comes from the wire nesting between the pair below it. The force is substantial on the cheek plates of winch drums.

 

[Compositepro]

Force on cheek plates is due to cable tension. In a cable carousel the cable is loaded at low tension. The tensile strength/stiffness of the cable prevents the hoop from expanding after being laid in the carousel. The carousel is mainly bracing to keep the pile stable.

If the carousel tilts, in inside core will carry almost all of the side loads.

Also, you cannot have a closest packing configuration because each layer will alternately be spiraling inward and outward.

 

[BEMPE16524]

TugboatEng, I'm not so worry for a winch drum because I've designed one. Also I can refer to DNV Standard for Lifting Appliances.
What Compositepro said about the winch cheek plate (flange) is correct. Also the loading taken by the center core does make sense. No wonder I see all the outer core of the carousel are designed in such a simple way.

R.Efendy