Request info on salt water erosion on 70 year old war ships

[subveteran]

To Whom ever.

I am a retired submarine veteran and at once time a indirect caregiver of a United States Submarine tha was built in 1943 and is at present, under the control of the San Francisco Marine National Park Association and since the Boat was awarded this organization, the boat was scheduled for dry docking every five years. The Association budgeted $ 400,000.00 over five yeass for this need. some five years ago, when we were advised that the Boat was going to stay in salt water for EIGHT years, many Sub Vets were in an uproar, claiming the Boat could not sit in the water for eight years with out "irreparable harm". It was then we found out the reason the Boat did not go to dry dock as scheduled, was because the SFMNPA used the $400,000.00 for dry docking of other needs. However, the up roar caused the SFMNPA to find some $280,000.00 to get a much "below water" maintenance on the Boat. Now, five years have cone and past and now the Executive Board, has announced the Boat will NOT be going to dry dock in five years but will remain in Salt Water for a total of at least eight and possibly nine years, This is acceptable, because of expert "in house" engineers that "no irreparable" harm will take place, which I believe to be a ludicrous if not an outright lie. I entered the site "ASK" typed in "Salt Water and steel" and the first items I saw, referenced salt water and steel regarding "Ballast Tanks" and how useless "zinc" is on stopping erosion and/or rust, because Ballast Tanks, typically 1/2 full of water and salt air. Exactly describing a submarine. My question to anyone who could respond, what would be the absolute minimum time a Submarine, especially one who that has been sitting in salt water for almost 74 years, should be dry docked, before sinking at the pier. I do not know if this a the correct medium to ask for help in this matter but any response would be welcome, Thanking you in advance for any help or response you can give me and my Shipmates would be greatly appreciated,
Sincerely "SubVeteran"

 

[MikeHalloran]

I wonder how said engineers propose to deal with the "reparable" harm.

Did they produce a report?



Mike Halloran
Pembroke Pines, FL, USA

 

[EdStainless]

There are three areas of concern
1. Ballast tanks
2. Places on the hull where dissimilar metals are joined
3. hull penetrations (cooling water lines and such)

Does the boat have a cathodic protection system installed?
This is commonly done when ships and boats are permanently docked. The install a grid of sensors and electrodes so that they can impress a current to minimize corrosion.
Another way to do this is to install sacrificial anodes (zincs) that will corrode instead of the hull. The trick is to inspect them and make sure that there is enough Zn left to provide protection.

8 years sounds long to me....


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Plymouth Tube

 

[chicopee]

I would "torpedo" the whole project if I were you because in the next five to eight plus years you will be looking for another half a million dollars to dry dock the sub, then when time is up it will be another 5 to 10 years. Sounds like there is hanky-panky with the funds.