Terry,
Thanks very much for posting the USCG Buffalo link! Some great stuff on that site, and it's the first place I've seen it where it's made publicly available to a lay audience for free. I've seen a lot of the material in industry sources and trade pubs, but not all in one place like the CG link. The Coast Guard provided financial sponsorship to at least one of the studies that Rivkin and Shafer did. Kevin Ritz' presentation was presented free by the ABYC last summer as a webinar, but the shoreside follow-up was for ABYC members only. That second webinar covered the NEC 555 and shore-side infrastructure issues.
Ritz' video may still be available on the ABYC website, and I strongly recommend it to every boater. It's easier to understand the material if you hear the words behind the slides.
Did you notice that all of the fatalities and electric shock injuries the authors documented occurred in fresh water? Boaters in the Great Lakes and in the Great River systems - in fresh water anywhere - please, please learn about this issue and understand it! It is a true killer!
It should be the policy at marinas and yacht clubs everywhere that swimming is never allowed in the boat basin. No one should ever swim near boats connected to shore power; especially in residential neighborhoods around private docks. Leakage current is a shore power phenomena; current gets into the water and finds it's way through the water back to the source on shore. Because current will always return to it's source of supply, you don't have the same scenario when running from an onboard genset or inverter. In the case of an onboard genset/inverter, even if there's a fault aboard, and even if the integrity of the vessel's bonding system is simultaneously compromised, and even if the fault energizes metals in the water, any current flow will occur at the interface between the hull and the water (fiberglass hull) to a better bond return path, or through the hull (steel hull), because the source in that scenario is inside the hull, not outside and away from the hull as is true with shore power. With onboard sources, fault current would not flow outward from the hull where swimmers would be affected. The absolute risk from onboard sources is not zero, but it's many hundreds of times less than the risk with shore power.
And in light of another recent risk conversation, I might add that the "probability" of Electric Shock Drowning" is statistically quite low. Ah, but "impact" is, well, off the scale! Protect yourself from this uninvited and unwelcome killer!
Jim
Peg and Jim Healy aboard Sanctuary
Currently at Charlotte Harbor, Punta Gorda, FL
Monk 36 Hull #132
MMSI #367042570
AGLCA #3767
MTOA #3436
Terry,
Thanks very much for posting the USCG Buffalo link! Some great stuff on that site, and it's the first place I've seen it where it's made publicly available to a lay audience for free. I've seen a lot of the material in industry sources and trade pubs, but not all in one place like the CG link. The Coast Guard provided financial sponsorship to at least one of the studies that Rivkin and Shafer did. Kevin Ritz' presentation was presented free by the ABYC last summer as a webinar, but the shoreside follow-up was for ABYC members only. That second webinar covered the NEC 555 and shore-side infrastructure issues.
Ritz' video may still be available on the ABYC website, and I strongly recommend it to every boater. It's easier to understand the material if you hear the words behind the slides.
Did you notice that all of the fatalities and electric shock injuries the authors documented occurred in fresh water? Boaters in the Great Lakes and in the Great River systems - in fresh water anywhere - please, please learn about this issue and understand it! It is a true killer!
It should be the policy at marinas and yacht clubs everywhere that swimming is *never* allowed in the boat basin. No one should ever swim near boats connected to shore power; especially in residential neighborhoods around private docks. Leakage current is a shore power phenomena; current gets into the water and finds it's way through the water back to the source on shore. Because current will always return to it's source of supply, you don't have the same scenario when running from an onboard genset or inverter. In the case of an onboard genset/inverter, even if there's a fault aboard, and even if the integrity of the vessel's bonding system is simultaneously compromised, and even if the fault energizes metals in the water, any current flow will occur at the interface between the hull and the water (fiberglass hull) to a better bond return path, or through the hull (steel hull), because the source in that scenario is inside the hull, not outside and away from the hull as is true with shore power. With onboard sources, fault current would not flow outward from the hull where swimmers would be affected. The absolute risk from onboard sources is not zero, but it's many hundreds of times less than the risk with shore power.
And in light of another recent risk conversation, I might add that the "probability" of Electric Shock Drowning" is statistically quite low. Ah, but "impact" is, well, off the scale! Protect yourself from this uninvited and unwelcome killer!
Jim
Peg and Jim Healy aboard Sanctuary
Currently at Charlotte Harbor, Punta Gorda, FL
Monk 36 Hull #132
MMSI #367042570
AGLCA #3767
MTOA #3436
