Electric magnetic field heath problems and sea sickness

[Ralsy]

In alot of boats, passengers sit very close to electrical systems (such as batteries) of significant power, usually for a considerable amount of time. Apparently the currents achieved in these systems and the short distances between the power devices and the passengers mean that the latter could be exposed to relevant magnetic fields. In my case approx 1000 amp 12v battery bank underneath the main cabins bed, around 12 inches below the bottom of the mattress. I'm wondering if the hazards of magnetic field exposure or electromagnetic radiation (EMR) must be taken into account?
Is it usual to put such a large storage of batteries under the bed you potentially spend 1/3 of your day on?
The previous owner of this particular boat has told the broker he doesn't want anything more to do with the boat as all his family members get sea sick on the boat and most other people aswell if they come aboard for any extended lenght of time.
The sea sickness could be enhanced by the relatively narrow beam to length of the boat aswell as the heavy steel superstructure which could make it a little rolley at times. It's a 55ft long, 15ft beam, 45 tonne steel displacement pilothouse cruiser. There is a stability report available on the boat which stipulates the necessary requirements for when cruising such as making sure fresh water tank is full, gray and black are empty, centre fuel tank is empty, the other 4 are balanced except for tank number 1 which needs to have 350 litres of fuel less than tank 4. The boat does have Naiad Stabilizers but still thinking it could potentially be quite rolley.
So there are 2 questions,
1 - could the close proximity of the batteries be a potential health problem OR add to the sea sickness of passengers through the EMF on a steel boat?
2 - could the build of the boat as described be a problem in anything but smooth cruising conditions?
I have been for a sea trial but unfortunately conditions were smooth.

 

[MYTraveler]

So there are 2 questions,
1 - could the close proximity of the batteries be a potential health problem OR add to the sea sickness of passengers through the EMF on a steel boat?
2 - could the build of the boat as described be a problem in anything but smooth cruising conditions?
I have been for a sea trial but unfortunately conditions were smooth.

1. I don't see how proximity to the batteries could have any health impact unless you are breathing charging gasses. Also, batteries do not create electro magnetic fields -- only electrons moving through a circuit do. And those fields are not very powerful (in relative terms) -- If a compass still points north, then the earth's magnetic field is demonstrably more powerful.

2. It does sound like the boat lacks stability (and its narrow beam certainly can't help in that regard). I recommend that you sea trial it.

 

[Ralsy]

Thanks for your reply.

 

[rgano]

Adhering to all of those tank filling restrictions is not feasible in the real world on a day-to-day cruising basis.

 

[Ralsy]

Adhering to all of those tank filling restrictions is not feasible in the real world on a day-to-day cruising basis.

Yeah, doesn't sound practicable. Spoke to broker who advised, he'd just fill the tanks and go. Not sure why he wouldn't take on board the recommendations from the stability report. Is it normal for a boat to have a stability report?

 

[gsholz]

Re health risks, a battery at rest has no appreciable magnetic field. Once you start pulling current or charging them, there will be a weak magnetic field around the conductors. The field diminishes with the square of the distance.

The particle that carries the electromagnetic force is the photon. A photon's energy is determined by its frequency, i.e. how quickly it moves back and forth. You need to get up into the Giga (Billion) Hertz range (e.g. microwave, radar) or way beyond (e.g. UV light) before you can harm living things. Electromagnetic waves of all frequencies have been all around us since the beginning of time.

Re stability report. Most likely, the stability report just lists the conditions under which the testing or calculation was performed. It does not mean the boat is more or less stable in other configuration. It just was not tested there.

 

[Benthic2]

I would never want to own a boat that had so many stipulations needed to acheive acceptable stability. What good is a center fuel tank if using it makes the boat unstable ? Was something significan't added to the boat later in life, like a fishing tower or flybridge ?

 

[Ralsy]

Here are a few pages on this boats operating procedures.

 

[OldDan1943]

There are a lot of people with pacemakers living on boats suffering no ill affects.
Maybe the owners friends get sea sick very easily.
If you are that worried about it, start looking at other boats or consider a RV.

 

[Ralsy]

There are a lot of people with pacemakers living on boats suffering no ill affects.
Maybe the owners friends get sea sick very easily.
If you are that worried about it, start looking at other boats or consider a RV.

Didn't know that RVs float?

 

[Comodave]

55’ with a beam of 15’ seems very narrow to me. I had a 46’ that had a beam of 16’ and it was very stable.

 

[Oldersalt]

If you are worried about the effects of EMR from your 12-volt batteries, I hope you are not using a cell phone, or even getting near to one.

 

[Ralsy]

If you are worried about the effects of EMR from your 12-volt batteries, I hope you are not using a cell phone, or even getting near to one.

Not really sure, but feel reasured that most people think it's not an issue.

 

[Lou_tribal]

At least you have a good operating manual that you can update based on your experience with the boat.

L

 

[GoneFarrell]

If the boat ever turned turtle and insurance found this thread, would they pay up?

Keep looking, plenty of other boats out there without stability agenda to be concerned about.

 

[Codger2]

=GoneFarrell;894447Keep looking, plenty of other boats out there without stability agenda to be concerned about.

 

[HopCar]

People have been getting sea sick long before batteries were invented.

 

[Insequent]

55’ with a beam of 15’ seems very narrow to me. I had a 46’ that had a beam of 16’ and it was very stable.

My boat is stable, and has length of 50' and beam of 15'6". I don't see the length to beam ratio of the boat in question being unusual.

I have Naiad's and they keep the boat flat underway in most conditions. If they are sized appropriately and operating then no-one should get seasick underway.

At anchor it sounds like flopper stoppers are needed. I'll also be adding those before my next Great Barrier Reef trip where you often find yourself trying to anchor in adverse conditions. eg wind at 90° to tidal current, waves from 15-20kn winds topping the reef at high tide and generating roll for a few hours.

The tank balancing & loading regime, together with an apparent tendency to make crew seasick, heavy steel superstructure, and existence of a stability report all suggest to me that the boat needs a bunch of ballast. Was ballast removed by someone at some point? Best to get an NA to use the stability report, plus further tests if required (eg inclining test), to get that sorted as to how much ballast and where. It might not cost that much to do.

 

[Ralsy]

My boat is stable, and has length of 50' and beam of 15'6". I don't see the length to beam ratio of the boat in question being unusual.

I have Naiad's and they keep the boat flat underway in most conditions. If they are sized appropriately and operating then no-one should get seasick underway.

At anchor it sounds like flopper stoppers are needed. I'll also be adding those before my next Great Barrier Reef trip where you often find yourself trying to anchor in adverse conditions. eg wind at 90° to tidal current, waves from 15-20kn winds topping the reef at high tide and generating roll for a few hours.

The tank balancing & loading regime, together with an apparent tendency to make crew seasick, heavy steel superstructure, and existence of a stability report all suggest to me that the boat needs a bunch of ballast. Was ballast removed by someone at some point? Best to get an NA to use the stability report, plus further tests if required (eg inclining test), to get that sorted as to how much ballast and where. It might not cost that much to do.

Ballast is apparently there. Full oil filled keel with added lead ballast.

 

[Ralsy]

I see many steel boats with aluminium super structure. Must be because they're trying to lower center of gravity to increase stability.

 

[GH41]

I think the part about requiring the fly bridge clears to be open in strong winds would be enough to send me on my way!

 

[Bduffey]

These Well thought out responses are why the forum is so important for all of us owners.

I agree that magnetic fields are not a culprit here. I would be concerned with the vapors from the batteries being recharged. I would assume the batteries under a bed would be in a sealed and well ventilated space. I personally would not want them under my bed and they would be relocated, but that is me.

Seasickness is almost always caused by motion. Perhaps the boat in question has a somewhat unique 3 axis (roll, pitch and yaw) movement that is more likely to cause motion sickness.

Having said that, the naiad Stabilizers are invaluable to smooth out the roll. We have a 44 Defever and I personally wouldn’t consider one without stabilization. We did the crossing from Carabelle to Clearwater and the weather report was a bit optimistic. We ended up in 6 foot seas with a stiff wind. Our fleet was A Nordhavn 40, another unstabilized Defever 44 and a Jefferson 47 We kept in sight for the crossing and We clearly had a far superior ride. The PO added the stabilizers at Stabilized Marine in Lauderdale and It looks like an original install. So that’s an, albeit expensive, option.

Anyone feeling ill while underway should be where they can see the horizon and have good ventilation. Nothing is worse than the smell of exhaust. Going below when you feel bad is almost a guarantee you will get worse. I usually run from the flybridge and I would get the person up there steering to keep their mind off it.

Batteries are great ballast. Perhaps a relocation to a lower location within the Hull would improve the stability a bit. I know finding a location for Them is challenging to near impossible in some boats, but in a boat that large there should be some options. Battery cables USA made custom high quality cables for me in whatever gauge, length and termination needed at a reasonable price and a <24 hour production time.

I think you have a solvable problem. Fuel and water are variable ballast depending on level and location of the tanks. Perhaps some experimentation with various levels combinations would improve the stability both underway and at rest.

Good luck and safe travels.

 

[OldDan1943]

Inner ear aggravated by smells.

What can mess with a person is the snap roll. Ie, just as the bow is about to plunge into a wave, a quick roll to port or starboard .... grab the bucket.

There are a lot of folk medicine out there, saltine cracker, ginger, candy, magical wrist straps etc.

Of course eating anything greasy is not recommended until both the weather and you calm down a bit.

When I had my stabilized N46, running at night and watching the bow bury itself in a wave, l green water against the pilot house windows, was fun and exciting. That Nordhavn was designed for rough weather and would survive it far better than the people inside.

I dont think my AT is designed for that kind of action. LOL

 

[PM]

That is pretty narrow for a 55 foot boat. It may or may not contribute to the problem. The shape of the bottom is probably more important than length vs width.

Batteries DO NOT have a magnetic field. In fact the old myth that batteries will discharge themselves if left sitting on a concrete floor have been disproven numerous times by experts. Although you will see that most marinas and other facilities still store batteries on boards or racks or whatever.

pete

 

[OldDan1943]

That is pretty narrow for a 55 foot boat. It may or may not contribute to the problem. The shape of the bottom is probably more important than length vs width.

Batteries DO NOT have a magnetic field. In fact the old myth that batteries will discharge themselves if left sitting on a concrete floor have been disproven numerous times by experts. Although you will see that most marinas and other facilities still store batteries on boards or racks or whatever.

pete

I have been corrected many times. So I stand corrected.

I think this goes back to the WWII era when battery cases were made of pretty much anything.

I think shops still store them on boards to ease picking them up, especially 8D batteries.

 

[Capitaine R]

Didn't know that RVs float?

They do, at first but not for very long.

 

[OldDan1943]

They do, at first but not for very long.

Depends if you leave the doors open.

 

[Northern Spy]

That is hardly a stability report. I think the pages from the owners manual just show a meticulous, or perhaps merely, over-cautious owner, that knows how the vessel rides best by experience.

If this is the boat in question, she's quite lovely.

https://www.boatsonline.com.au/boat...g-range-displacement-flybridge-cruiser/228640

https://geofflovettint.com/pacifica-55-passagemaker-long-range-cruiser/

 

[DarrenCharles]

It is not beyond the realm of possibility that spending 1/3 of your day next to a relatively high EMF may affect your health. The batteries create an electric field when there is no moving current. When there is moving current (electricity is flowing) they also create a magnetic field (along with the wires).

There are some test results that suggest a high EMF may lead to a greater risk of childhood leukemia, but the tests are not conclusive.

I suggest gettting your hands on a gaussmeter, which is used to measure EMF, and measuring your sleeping surface. Compare that reading to an average exposure. The average exposure is about 2 milligauss throughtout ones day. If you are in that range, I wouldn't worry about it. If you are significantly higher, you might want to investigate further.
I was particularly concerned about this issue because we purchased land next to a 115kv powerline on which to build our home. We took measurements. Readings were high near the powerlines but dropped off fast so we bought the property and built a house. Interestingly readings are quite high next to a microwave oven in the kitchen.

I am also a licensed professional engineer and inquisitve by nature.

Here is a link with probably more than you want to know.

https://www.niehs.nih.gov/health/ma...c_power_questions_and_answers_english_508.pdf

 

[KnotYet]

It is not beyond the realm of possibility that spending 1/3 of your day next to a relatively high EMF may affect your health. The batteries create an electric field when there is no moving current. When there is moving current (electricity is flowing) they also create a magnetic field (along with the wires). edit

As an engineer, what is the nature of the electric field when there is no moving current?
What is the unit of measurement? How is it measured?
It would seem with no current, the batteries are large boxes of metals and chemicals.