Underwater inspections

[oneintheeye]

what would you say is the recomended frequency for an underwater inspection of a harbour structure. The structure has cathodic protection. (steel tube piers).

 

[dik]

I would suggest that the first couple of inspections occur on a monthly basis, then a few on a three month basis and then a few semi-annually and then a few on an annual basis. If there is any change between reviews, then the frequency can be adjusted.

Dik

 

[ImminentCollapse]

Is it in an area where scour is a concern, say an inlet, mouth of a river or has large tidal fluctuations? If not, dik's schedule may be a little agressive and your major concern over time will be the splash/tidal zone on the piles. It also depends some on the use, if it is hospital (unlikely) or warehouse etc.....

IC

 

[oneintheeye]

its in a harbour. Not sure why you would put a hospital in a harbour That inspection regime does seem excessive to me, maybe? The risk to persons is relatively low (in terms of numbers at least) but economically would be a disaster for the client. Any thoughts on scour potential in a harbour?

 

[BlastResistant]

I'm not sure where you are located, but in the US the norm is 5 year maximum interval. Check the publication "Specialized Underwater Waterfront Facilities Inspections," which is a US Navy publication NAVFAC MO-104.2. Google "NAVFAC MO-104.2" and it will lead you to a link to a free pdf download. On page 3 it recommends 6 years maximum intervals. The document also describes different "levels" of underwater inspections (Levels I, II, and III). Good luck.

 

[msquared48]

For the boat we used to have, I had to change the zincs once a year, and they were usually pretty degraded by that time. It was in salt water 24/7.

For this application, depending on the size of the zincs used, if that is the mechanism for protection, I would start with every six months to get a record of degredation, and modify the time as needed once a history is developed.



Mike McCann
MMC Engineering
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