Lay length of Mooring line

Wind & Water General
1

Hi everyone

I would like to know the lay length of the moorning line from FAST . Could anyone kindly help me in locating it.

Thanks
Krishnaveni

2

Hi Krishnaveni,

Which mooring module are you using?

Best regards,

3

Am using Moordyn , So can I take the node positions and look at the point till z starts picking up . After which resultant of x and y coordinates till that pick up (typically am assuming it as touchdown) , can this give me lay length of an individual line?

4

Dear Krishnaveni,

Yes, that makes sense to me. Perhaps Matt Hall–the developer of MoorDyn–will comment further.

Best regards,

5

Hi Krishnaveni,

I agree with Jason that your proposed approach is a good solution.

Because MoorDyn is a lumped-mass model, the calculated touchdown length will change abruptly as a node touches down or lifts off. However, if you have enough nodes (short enough segments) the jumps in touchdown length can be made relatively small.

Best,
Matt

6

Thank you Jason and Matt, Your guidance helped a lot . I have a general question related to that . Say for a given Spar (say OC3) with three mooring lines. Does the initial lay length at 0 time step should be same or it does vary depending on the discretization of nodes. Kindly throw some light on this…

7

Dear Krishnaveni,

I’m sorry, but I don’t really understand your question. As Matt pointed out, the lay length will converge with an increasing level of discretization.

Best regards,