Cathodic Protection for Skirt Pile

[ejesper]

I am currently designing a cathodic protection system for an offshore platform and accounting a problem in providing CD to the skirt pile. The skirt pile cannot be electrically connected to the jacket due practical reasons. Is there any methods I can consider?

 

[StephenA]

If it is not electrically connected you could use sacrificial anodes but I would expect that you have already thought of that.

Stephen Argles
Land & Marine

http://www.landandmarine.com

 

[fdac]

I would suggest finding a way to achieve continuity - with large aluminium anodes putting out several amps each, typical on offshore jackets, there is some risk of stray current interference if parts of the structure are not connected.

What is the configuration of the skirt pile - do you mean the piles driven down inside jacket legs? If so they may well touch the legs anyway.

 

[civilperson]

Separate bags of magnesium or zinc attached to the skirt with bonded cables.

 

[fdac]

Bagged anodes are not normally used offshore in my experience; how impractical is it to achieve continuity?

Surely no more impractical than attaching separate anodes after driving skirt piles. Drill and bolt with air tools, wet weld tack, even a clamp and set screw would do it.