Electric magnetic field heath problems and sea sickness

[chris95040]

Originally Posted by Ralsy

1000 amp 12v battery bank

Originally Posted by SVHarmonie

55 feet and 45 tonnes? Awwww, come on. I don’t think so! That’s 900,000 lbs!

Oh internet, you never disappoint.

[a64pilot]

[QUOTE=Jim Cate;3175886]

Not saying an electric blanket or a water bed heater will necessarily harm you, but why put yourself in that RF field unnecessarily?[/QUOTE

Umm, mate, 60 hz is hardly RF...

Jim

OK, so EMR then.

[Ralsy]

Originally Posted by chris95040

Oh internet, you never disappoint.

4 x Lifeline GPL-8DA 12 Volt 255 AH AGM Deep Cycle*= 1020 AH battery bank?

[Wotname]

Originally Posted by Ralsy

4 x Lifeline GPL-8DA 12 Volt 255 AH AGM Deep Cycle*= 1020 AH battery bank?

Yes, that is correct however 1020 AH does not mean its a 1020 ampere (12V) battery bank.
It means it is a 1020 ampere hour (12V) battery bank which is a completely different thing.

[Ralsy]

Originally Posted by Wotname

Yes, that is correct however 1020 AH does not mean its a 1020 ampere (12V) battery bank.
It means it is a 1020 ampere hour (12V) battery bank which is a completely different thing.

Ahhh, I get it now. Thanks for that. Still trying to get my head around electrics. Apologies to everyone for that.

[StuM]

Originally Posted by a64pilot

Maybe,
There was a study that got squelched quite quickly about AH-64 pilots and brain tumors. The helmet we wore had very c right up against our head and we had a cathode ray tube strapped to the right side of our face, there was significant RF, and the incidence of brain tumors over the general population was exceedingly high.
As Stu said distance is extremely relative.
I used to sleep in a water bed, the last one I purchased a low voltage DC heater as it’s RF is very low, but it’s one reason why I won’t sleep under a 110V electric blanket.
Not saying an electric blanket or a water bed heater will necessarily harm you, but why put yourself in that RF field unnecessarily?

RF field? 3kHz to 300 GHz!


Your CRT would possibly create an RF field (and also emit X Rays), but how do you get a "Radio Frequency" field out of a 50/60Hz alternating current or a DC current at any voltage?

[Wotname]

Originally Posted by Ralsy

Ahhh, I get it now. Thanks for that. Still trying to get my head around electrics. Apologies to everyone for that.

All part of the grand learning curve! No one is born with an understanding of electricity ad we aren't taught much about it in our early formative years.

Keep up the effort .

[billgewater]

Attached to your cochlea(s) are three semi circular canals. They are placed mutually at approximately 90 degrees and contain a fluid that washes past very fine hairs as your head rotates in the three directions (spinning sideways, nodding up and down and rocking sideways.) (A rough description). These sensory messages go to your brain that correlates this motion with what your eyes are telling you etc.
If you sit on a spinning chair for a while then the continuous rotation in the horizontal plane will eventually drag the fluid along with the tube. When you stop spinning and stand on the floor, the liquids' inertia means it continues moving in the horizontal tube. This sends a message to your brain that you are still spinning but now in the opposite direction you were previously spinning. Your eyes tell a completely different story as do your feet. Your brain gets confused. It's called "being dizzy". The tubes are essentially the sensory devices for maintaining balance but they can be easily confused particularly by motion that does not correlate with the other senses. So it makes sense that keeping a good eye on an horizon and avoiding jerking motion should reduce the confusion. Just why all this can make people wish to remove contents from their stomach is a mystery to me. But it may be that the bits of your brain that demand expulsion of unwanted stuff in the stomach may be affected by the mental confusion brought about by the contradictions between the different sensory inputs.
Things also get embedded in the brain as I recall getting off a rough trans Tasman trip and went ashore to the toilet. When I closed the door I had to prevent myself from falling over. I felt seasick or at least wobbly. Maybe the brain had adapted to the rolling motion and was now confused when it stopped.
Maybe this for forum is a good place to discuss how to best manage sea sickness.

[Scorpius]

Originally Posted by SVHarmonie

55 feet and 45 tonnes? Awwww, come on. I don’t think so! That’s 900,000 lbs!

Let’s do some quick calculations here:

55 ft * 15 feet * 0.75 (prismatic coefficient) gives us a water plane area of about 619 sq feet. So each foot of immersion would displace 619 cubic feet. At 64 lbs/cu foot, that’s 39,400 lbs. JUST to float the boat would have to draw 900,000/39,400 = 22 Feet. No wonder it has “stability issues.”

You don’t need to pull the sharpest pencil from the box to know this is BS.

If I wanted to troll the forum, my post would look an awful lot like this one...

Let's try this again using 90,000 pounds shall we? Also maybe the 45T is REGISTERED Tonnage, not displacement. Two totally different things. My Registered Tonnage is 12.24. Displacement is 17.5. Panama Canal Registered Tonnage is 13.5 (I think; I lost the certificate). Go figure.

[a64pilot]

Originally Posted by StuM

RF field? 3kHz to 300 GHz!


Your CRT would possibly create an RF field (and also emit X Rays), but how do you get a "Radio Frequency" field out of a 50/60Hz alternating current or a DC current at any voltage?

Again, I corrected to EMR, I misspoke.

[Jammer]

Originally Posted by barnakiel

Furthermore, it is very bad to stand close and in line with a radiating radar antenna.

Of olden times when the transmit power was higher it was seen as a great way to stay warm on morning watch

[a64pilot]

Originally Posted by Jammer

Of olden times when the transmit power was higher it was seen as a great way to stay warm on morning watch

I could only hope that no one really did that?
An Army friend worked on the NJ F-106’s. According to him they could fire up that old Radar and light up whole buildings a half mile away on the airfield. That would be RF.

[GILow]

Back to the original question....

A boat that needed that sort of micro-management of the tanks would scare me badly.

I know how much of a nuisance it was when my boat had diesel and water on opposing sides of the boat, and with nearly ten tons of lead in the keel I’d hardly say my boat was unstable.

No, having to balance all those tanks to remain safe would be a deal breaker of no uncertain terms to me.

[dorymate]

My advice to you is if you have to mess with the tanks as you said then I would certainly walk away for safety sake if nothing else...

[dorymate]

Maybe when you see how many posts I've made over the years you may question my reason for replying..well I am a retired Merchant Marine Master and I have had experience during my tenure as Master with a small Passenger Vessel of 120 feet in length with the same problems and this vessel was very unstable during bad weather conditions(very frightening at times to say the least) after a few years of operations the Naval Architects finally solved the problem by increasing her beam by welding sponsors along both sides this proved out to be very satisfactory...whole different ship..