SUBSIM Radio Room Forums - What happens when...

SUBSIM Radio Room Forums (https://www.subsim.com/radioroom/index.php)

- Silent Hunter III (https://www.subsim.com/radioroom/forumdisplay.php?f=182)

- - What happens when... (https://www.subsim.com/radioroom/showthread.php?t=119781)

Quote:

Originally Posted by Paajtor

I am not sure, whether the Faraday-effect would protect crew & boat entirely.

It should. All the electricity should stay on the outer surface of the boat. However, if the boat was on the surface when the lightning struck, there would probably be lookouts on the bridge. And since the bridge was the highest part of the boat... well, I wouldn't want to be one of the lookouts. Even if the lightning struck some other part than the bridge, the potential differences caused by the current of the lightning would likely cause a nasty (if not lethal) shock.

Quote:

Originally Posted by Puster Bill

You've also got AA and deck gun ammunition to worry about, especially those in 'ready' containers outside the hull.

If the containers were metal, the faraday-effect should keep the electricity outside. And if they weren't metal, they most likely weren't conductive enough for much electricity to pass inside.

Decided to test Faraday Cage effect during last night's thunderstorm. Sat in a tin bath of water on front lawn. Am now devoid of all body-hair and have difficulty hearing approaching DDs. Please advise.

Quote:

Originally Posted by Paajtor

I am not sure, whether the Faraday-effect would protect crew & boat entirely.
Maybe the ocean-water conducts lightning better than a metal Uboat? If so, then lightning would find an easier channel straight towards the ocean-surface, then to a Uboat.

But I do know, that lightning is a pretty rare event out on the open oceans.
Check this map....taken from this article.

Quote:

Lightning. It avoids the ocean, but likes Florida. It's attracted to the Himalayas and even more so to central Africa. And lightning almost never strikes the north or south poles. These are just a few of the things NASA scientists have learned using satellites to monitor worldwide lightning.

Water naturally isnt a very good conducter, but of course it will conduct but not to the same degree as lets say, copper. To increase the conductivity of water, some sort of acid would have to be added to it (any physics student should know this). Also lighting srickes the highest thing from ground leval no matter if its wood or lets say, a U-Boat.

The farady effect would not occour (someone will probably tell me I'm wrong) because the U-boat is earthed all the time from the water and thus sending the charge down to the bottom....

What would happen to the men inside ? I dont really know, and I sure as hell dont want to be the one who finds out!

Quote:

Originally Posted by KeybdFlyer

Repeat experiment whilst holding a long metal object to simulate the periscope. Your doing good work there and we all appreciate it. If you dont report back within 12 hours we'll have the answer to the question one way or another :up:

Hmmm...

Interesting topic. Something to consider, in all our deliberations on this one.

I can't speak for the Kreigsmarine, but I know that on many steel-hulled US vessels, a sacrifical anode is suspended from the ship's hull (underwater). Here's a good description from Wiki:

Quote:

In cathodic protection, a metal anode that is more reactive to the corrosive environment of the system to be protected is electrically linked to the protected system, and partially corrodesironsteel ship's hull may be protected by a zinc sacrificial anode, which will dissolve into the seawater and prevent the hull from being corroded. Sacrificial anodes are particularly needed for systems where a static charge is generated by the action of flowing liquids, such as pipelines and watercraft. or dissolves, which protects the metal of the system it is connected to. As an example,iron or steel ship's hull may be protected by a zinc sacrificial anode, which will dissolve into the seawater and prevent the hull from being corroded. Sacrificial anodes are particularly needed for systems where a static charge is generated by the action of flowing liquids, such as pipelines and watercraft.
At least one anode is found in tank-type hot water heaters. The anode should be removed and checked yearly, and replaced if 6 inches (15 cm) or more of bare wire is showing. This will greatly extend the life of the tank.

Note the last part about a hot water tank; a good wrench, and you can see what that anode looks like for yourself.

I would surmise that such a sacrificial anode would serve a dual purpose of "grounding" any current from a lightning strike to the water around the exterior hull, in addition to protecting the hull from corrosion, but I'm only guessing.

I know that the Taney, in Baltimore, also has a steel grounding cable from her hull to a pierside cleat, to dissipate any lightning that may hit that ship. Whether or not this serves to alleviate the hit her anodes would take, I don't know.

Anyway, just something to think about.