ROV Impact and Snagging Loads

[WanderingEng]

Hi,

I’m looking for some advice. I need to design a subsea pipe and ensure that it can withstand ROV impact and snagging loads.

Can anyone provide some advice as to which equations to use for calculating these loads. I’ve checked the DNV RP’s and they don’t seem to cover snagging loads and ROV impact loading.

Would it be similar to trawl board impacts?

Thank you

 

[LittleInch]

I'm having difficulty in imagining that an ROV impact or snag is anywhere near as bad as a trawl board or fishing gear snag.

I know they are quite big, but they don't go very fast.

A towed sonar line is probably worse.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[Ussuri]

1) You could take a look in ISO 13628-8 ROV Interfaces on subsea production systems. It presents loads that ROV can apply during operation.
2) You can review some ROV specification sheets to determine maximum thrust and mass and work from there.
3) You can review the manip manufacturers to see how much load the manip can apply. For example, Schilling.

I would question how an ROV will snag in the first place? Which part of the ROV are you concerned about getting caught and how? And if it is operating in the region next to the pipeline, it will hardly be moving, and very slowly.

The loads you get from DNV-RP-F111 will be much higher.