Subsea Structures - Fishing Gear Interaction

[RandomAxe]

I am trying to write a summary of options for subsea structures (manifolds etc). Obviously we can have a piled structure or a gravity based structure. Is there a design code that gives an overview of the options for dealing with fishing gear snagging? From research so far I have come across 'Over-trawlable' structures, which deflect the fishing gear, and also 'fishing friendly' structures, is this the same thing? Are there other options? Thanks

 

[SJones]

ISO 13628-15, ISO 13628-1 and NORSOK U-001


Steve Jones
Corrosion Management Consultant

http://www.linkedin.com/pub/8/83b/b04

All answers are personal opinions only and are in no way connected with any employer.

 

[London]

'Overtrawlable' is different to 'Fishing friendly' in terms of the qualifications required for an overtrawlable structures-its more onerous. Have a look at the NORSOK code listed above

 

[RandomAxe]

Thanks Chaps. Yeah I've been reading through Norsok but it makes no mention of 'fishing friendly' sructures? I haven't yet got a copy of the ISO-13628 codes but have requested from doc control. Thanks again

 

[Ussuri]

Overtrawlable structures have a profile which allows trawl gear to pass over the structure without getting snagged. Fishing loads are reduced, but not eliminated.

Fishing friendly are typically non overtrawlable so fully snag trawl gear. This leads to higher fishing loads. A fishing friendly structure is designed so the envelope has no protrusions. This allows the fishing vessel to back the nets off after snagging the structure and free itself.

Non fishing friendly would snag nets and there would be no way for the vessel to free them.

Sometimes structures are located within an exclusion zone so fishing interaction is not considered.