Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Nov 2, 2016 3:02:37 GMT
I was watching the account of U-166 and looked it up on Wikipedia. Here is the reason i am writing this now: Note that after 74 years underwater, the main deck steel structure is not only intact, but also clean of growths, while the deck gun does have some growth on it. This puzzles me. Does anyone know why this difference in biofouling exists?
|
|
|
Post by thebastidge on Nov 28, 2016 15:45:36 GMT
A few feet in depth can make a big difference in some cases, with the amount of sunlight received. For example, coral growth drops off drastically over the course of a few feet rom the zone that gets enough sunlight to the zone that doesn't. Older coral below that is either dead or grows very slowly.
The currents can make a big difference too, with extremely localized scouring and just a few feet away, accumulation. Or it could be that sediment settles on the relatively flat deck and provides a poor substrate.
It's really hard to say.
|
|
|
Post by jeff on Nov 29, 2016 19:30:03 GMT
The Type IXC submarine outer hull used steel 42 (60000 psi tensile) specification KM 9104 While I cannot guarantee what I've found, I strongly suspect it is a stainless steel with Molybdenum, which would help explain the lack of biofouling. KM 9104 could be a Kriegsmarine spec, or might mean Krupp Molybdenum... www.uboatarchive.net/Design/DesignStudiesTypeIXC-S11.htmCONFIDENTIAL REPORT 2G-9C S11 FORMER GERMAN SUBMARINE TYPE IX C-40 HULL STRUCTURAL SUMMARY The hull is conservatively designed, and is believed to offer nothing currently constructive. While certain aspects are novel, it is believed that they are heavy and expensive solutions to the particular design problem.
|
|
|
Post by thebastidge on Nov 29, 2016 20:33:50 GMT
That's not really a lot of biofouling on the gun either. Most stuff I see when diving has more accumulation than that unless there's a pretty strong current. After that much time underwater, the whole thing could easily be difficult to identify. But it's all pretty clean, which indicates not much growth potential in the surrounding water for whatever reason.
Ah... reading the Wikipedia article further it's very easily explained. 5000 ft depth.
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Dec 2, 2016 3:46:22 GMT
Ah... reading the Wikipedia article further it's very easily explained. 5000 ft depth. Point taken, but it's still between 1 inch to 3 inches of growth vs nothing, which is a huge percentage difference on the gun vs deck structure.
|
|