Lightning Strikes - Any Real Experience ?

[Lagoon4us]

A discussion has come up regarding lightening strikes and their effect to respective yachts, can any contributors evaluate their actual experience/knowledge of a direct hit, near miss?

Just how unservicable did systems become? Regarding Rig and rigging, hard wiring, electronics etc

What earthing can be done that can help minimise damage?

[boasun]

To minimise the damage is to properly ground your antennas & radios. Thus all you will lose is the antenna and the radio that is connected to that antenna.

Have had a lightening strike on the SSB antenna of the 100 tonner I was captain of.
The antenna was shreaded, the tuner had its board burned out and the SSB had both of its boards burned out... Otherwise there was no other damage to the vessel.

Antennas & radios are easy to replace... People you care about, are not...

[Maine Sail]

We took a hit on our mooring in August 2010. Neighbor said the lightning hit the water right at our stern quarter. It did not come down the mast. The strike came in through the ground side of the system and took out nearly everything. Even the PSS seal had carbon blown all over the engine bay. It survived but it gave me the creeps... The only things to survive were a couple of pumps, macerator and shower sump.. We also lost a bunch of devices not even plugged in to anything. Lost the EPIRB, iPod, Laptop wifi and other features (laptop turned on but was severely compromised), three hand held GPS devices including one that was in a ditch bag wrapped in tinfoil & stored in a ziploc with desiccant.. None of these devices were even plugged in but were still toasted.

On the AC/DC panel some breakers survived and some did not. All volt gauges, tach, temp, etc. were also fried. Alternator VR was fried. All lighting aboard was LED and all was 100% toast except for one in the v-berth that still works, very odd. Engine starter survived but the solenoid died six months later no-doubt due to the lightning strike. Radar, wind, depth, speed, AP, two plotters, Garmin network hub, VHF, TV, stereo, cell phone amplifier and much more were all fried too..

The only wires damaged were very small NEMA type comms wires. All wiring survived just fine. Not one fuse was blown during the strike and the battery switch was off when it happened.

[Portobello]

A couple of years back in the middle of the appropriately named Storm Bay (Tasmania) on a hot day I was hit by a vicious storm cell - lightning, thunder, big hail stones and gale force winds from several directions over the course of 2o minutes. Lightning was striking the ocean all around us - we could smell it - but not once did we get hit - we were the only tall thing for quite a few miles in any direction and to this day I don't know why we were not hit. After 20 minutes it passed as quickly as it arrived and settled back to a balmy afternoon. I have heard of other boats in electrical storms not being hit. I wonder if it is common or rare to be actually hit?

[Lagoon4us]

Originally Posted by Maine Sail

We took a hit on our mooring in August 2010. Neighbor said the lightning hit the water right at our stern quarter. It did not come down the mast. The strike came in through the ground side of the system and took out nearly everything. Even the PSS seal had carbon blown all over the engine bay. It survived but it gave me the creeps... The only things to survive were a couple of pumps, macerator and shower sump.. We also lost a bunch of devices not even plugged in to anything. Lost the EPIRB, iPod, Laptop wifi and other features (laptop turned on but was severely compromised), three hand held GPS devices including one that was in a ditch bag wrapped in tinfoil & stored in a ziploc with desiccant.. None of these devices were even plugged in but were still toasted.

On the AC/DC panel some breakers survived and some did not. All volt gauges, tach, temp, etc. were also fried. Alternator VR was fried. All lighting aboard was LED and all was 100% toast except for one in the v-berth that still works, very odd. Engine starter survived but the solenoid died six months later no-doubt due to the lightning strike. Radar, wind, depth, speed, AP, two plotters, Garmin network hub, VHF, TV, stereo, cell phone amplifier and much more were all fried too..

The only wires damaged were very small NEMA type comms wires. All wiring survived just fine. Not one fuse was blown during the strike and the battery switch was off when it happened.

That's interesting regarding the three handhelds wrapped in foil i guess the intention was to create a faraday cage by doing that?
Wonder if a good faraday cage can be made to prevent damage, my only experience is using perforated steel? Any thoughts???

[Richard Harper]

This was my experience:
The Ligthning Strike

I put in a beefier ground connection. I added a fuse and transorb to each wire going to the mast and I disconnect the antenna when lightning is around. I added disconnect switches to the power lines going to the engines. I added a connector in the power line to the autopilot so I can disconnect it quickly. The GPS can also be disconnected quickly.
I don't know if any of this will work but I will tell you after the next hit.

[Lagoon4us]

Originally Posted by Portobello

A couple of years back in the middle of the appropriately named Storm Bay (Tasmania) on a hot day I was hit by a vicious storm cell - lightning, thunder, big hail stones and gale force winds from several directions over the course of 2o minutes. Lightning was striking the ocean all around us - we could smell it - but not once did we get hit - we were the only tall thing for quite a few miles in any direction and to this day I don't know why we were not hit. After 20 minutes it passed as quickly as it arrived and settled back to a balmy afternoon. I have heard of other boats in electrical storms not being hit. I wonder if it is common or rare to be actually hit?

My thoughts exactly, i'm wondering if the charged air causes damage to sensitive gear or if you need a more direct hit as was maine sails experience?

INTERESTING...

[Lagoon4us]

Originally Posted by Richard Harper

This was my experience:
The Ligthning Strike

I put in a beefier ground connection. I added a fuse and transorb to each wire going to the mast and I disconnect the antenna when lightning is around. I added disconnect switches to the power lines going to the engines. I added a connector in the power line to the autopilot so I can disconnect it quickly. The GPS can also be disconnected quickly.
I don't know if any of this will work but I will tell you after the next hit.

Wow good post, do you know where the charge exited? ie prop shaft, earthing plate???

[colemj]

We are currently refitting after a direct lightning strike. We have a "Strikeshield", which is a large diameter tinned copper cable that clamps directly to a fitting on the mast on one end and has an electrode with several feet of edge surface on the other end - that is immersed in the water. This was deployed at the time and probably mitigated structural damage on the boat by leading the main strike to water. There was no damage to the hull or rigging (boat was hauled and surveyed after the strike).

However, current still made its way down the sheath of the antenna coax and onto the negative side of the DC main bus. This pulse traveled through the DC system (on the negative side) and exited through the engine block that was connected to the inverter safety ground bond.

We lost every single piece of electronics and some of the electrics. The only things still working were the TV (plugged into a small inverter that was not switched on), the SSB (connected to a dedicated battery that is not part of the main house system), the battery monitor and the refrigerator (go figure...).

I have disassembled every component to look for damage or obvious avenues of repair.

The marine VHF and the autopilot computer were the only systems with visible component damage on their circuit boards. Anything containing logic circuits or computer control simply doesn't work anymore. Either it won't power up or powers up and reports gibberish or errors.

The current pulse is easily traced through the negative DC bus from the antenna coax shield. All fuses on the negative wires were blown apart while the fuses on the positive wires were OK (we have several ham radios on board with fuses on both wires). The inverter was on at the time and damaged, with the pulse getting on its metal case, traveling through the safety bond to the engine and out to water. The alternator on that engine lost its regulator, while the alternator on the other engine (not connected to the grounding system) was OK. When there was visible damage, the components blown on the circuit boards were universally diodes in places protecting from reverse polarity.

Two computers and various other equipment like cell phones, etc were plugged into the inverter when it was hit and suffered no damage. Many other small electronics like phones, handheld radio, two handheld gps's, two other computers, etc were lying around in the open not connected to anything and were not damaged. This points to the advice of putting things in the oven as possibly a wives tale.

In one cabinet was a router hooked to the house 12V power through a DC/DC converter, which was turned off at the main panel and two iPods - one connected to the inverter (I think) and one just lying in the cabinet unhooked to anything. A Ubiquity wifi system was also connected to the DC/DC converter through a POE connection. The router and both iPods were damaged - none of them would turn on. The DC/DC converter was toast. The Ubiquity system is OK. All of these items (except the Ubiquity) were within inches of each other and I believe the DC/DC converter created a localized EMP that took them out.

We have multiple other DC/DC converters on board powering stuff. They are all controlled at the main panel and none of them were switched on. All of them are internally shorted.

On the main panel, we lost a couple LED indicators and the DC ammeter. The DC voltmeter and AC volt and ammeter are OK.

Immediately after the strike, the ham radio turned itself on and tuned itself up at full volume. I turned it off. A few minutes later I noticed that it was very hot and pulled the power plug out of the back. Later, I found its fuse on its negative wire was blown, but the positive was OK. I replaced the fuse, but the radio never turned back on again. The coupler seems to be OK.

While grounding your radios may help, it will not contain the damage solely to the radio and antenna system like boasun suggests. A 100 tonner is a steel boat, which is about the best lightning protection system you can hope for, and explains the minimal damage he experienced.

I have talked to several people here who have been struck within the past two years. One reoccurring theme is that any components not damaged in the strike have been failing 6-12 months later.

I guess I will keep my eye on our battery monitor and reefer since they are the only things left running...

Mark

[Lagoon4us]

Originally Posted by colemj

We are currently refitting after a direct lightning strike. We have a "Strikeshield", which is a large diameter tinned copper cable that clamps directly to a fitting on the mast on one end and has an electrode with several feet of edge surface on the other end - that is immersed in the water. This was deployed at the time and probably mitigated structural damage on the boat by leading the main strike to water. There was no damage to the hull or rigging (boat was hauled and surveyed after the strike).

However, current still made its way down the sheath of the antenna coax and onto the negative side of the DC main bus. This pulse traveled through the DC system (on the negative side) and exited through the engine block that was connected to the inverter safety ground bond.

We lost every single piece of electronics and some of the electrics. The only things still working were the TV (plugged into a small inverter that was not switched on), the SSB (connected to a dedicated battery that is not part of the main house system), the battery monitor and the refrigerator (go figure...).

I have disassembled every component to look for damage or obvious avenues of repair.

The marine VHF and the autopilot computer were the only systems with visible component damage on their circuit boards. Anything containing logic circuits or computer control simply doesn't work anymore. Either it won't power up or powers up and reports gibberish or errors.

The current pulse is easily traced through the negative DC bus from the antenna coax shield. All fuses on the negative wires were blown apart while the fuses on the positive wires were OK (we have several ham radios on board with fuses on both wires). The inverter was on at the time and damaged, with the pulse getting on its metal case, traveling through the safety bond to the engine and out to water. The alternator on that engine lost its regulator, while the alternator on the other engine (not connected to the grounding system) was OK. When there was visible damage, the components blown on the circuit boards were universally diodes in places protecting from reverse polarity.

Two computers and various other equipment like cell phones, etc were plugged into the inverter when it was hit and suffered no damage. Many other small electronics like phones, handheld radio, two handheld gps's, two other computers, etc were lying around in the open not connected to anything and were not damaged. This points to the advice of putting things in the oven as possibly a wives tale.

In one cabinet was a router hooked to the house 12V power through a DC/DC converter, which was turned off at the main panel and two iPods - one connected to the inverter (I think) and one just lying in the cabinet unhooked to anything. The router and both iPods were damaged - none of them would turn on. The DC/DC converter was toast. All of these items were within inches of each other and I believe the DC/DC converter created a localized EMP that took them out.

We have multiple other DC/DC converters on board powering stuff. They are all controlled at the main panel and none of them were switched on. All of them are internally shorted.

On the main panel, we lost a couple LED indicators and the DC ammeter. The DC voltmeter and AC volt and ammeter are OK.

Immediately after the strike, the ham radio turned itself on and tuned itself up at full volume. I turned it off. A few minutes later I noticed that it was very hot and pulled the power plug out of the back. Later, I found its fuse on its negative wire was blown, but the positive was OK. I replaced the fuse, but the radio never turned back on again. The coupler seems to be OK.

While grounding your radios may help, it will not contain the damage solely to the radio and antenna system like boasun suggests. A 100 tonner is a steel boat, which is about the best lightning protection system you can hope for, and explains the minimal damage he experienced.

I have talked to several people here who have been struck within the past two years. One reoccurring theme is that any components not damaged in the strike have been failing 6-12 months later.

I guess I will keep my eye on our battery monitor and reefer since they are the only things left running...

Mark

Your experience makes a case for keeping say the VHF seperate from the house with maybe a knife switch for isolating charging.

I found the following info. Protecting your boat from lightning.
some good points there. Thanks

[Jon Hacking]

Originally Posted by Lagoon4us

A discussion has come up regarding lightening strikes and their effect to respective yachts, can any contributors evaluate their actual experience/knowledge of a direct hit, near miss?

Just how unservicable did systems become? Regarding Rig and rigging, hard wiring, electronics etc

What earthing can be done that can help minimize damage?

We took a near hit off Langkawi, Malaysia. Don't know where it hit as we were very busy at the time, but we got a flash/BANG, I thought to myself "I wonder who got hit" & looked down to see my instruments non-responsive. Ask not for whom the bell tolls...

But we were very lucky. We lost the radar (ancient JRC), the LED masthead light (but not the incandescent tri-color next to it) & the Raymarine ST6001+ control head (but not the autopilot brain!) The 6001+ fried its SeaTalk interface, which affected other instruments, but they were fine once the 6001+ was replaced.

My best guess was that we took only a near hit (near miss?) as we should have suffered much more damage. Nav-gear, laptops, interior LEDs, VHF, SSB, etc were all fine. OK, $4K lost, but we were VERY lucky.

We do not ground our rigging. My very casual & unscientific survey says that boats that do tend to have less damage, but also tend to get hit more often. With the electrical breakdown of air at 20KV/inch, I'd rather not have my mast at ground potential.

[Lagoon4us]

Originally Posted by colemj

We are currently refitting after a direct lightning strike. We have a "Strikeshield", which is a large diameter tinned copper cable that clamps directly to a fitting on the mast on one end and has an electrode with several feet of edge surface on the other end - that is immersed in the water. This was deployed at the time and probably mitigated structural damage on the boat by leading the main strike to water. There was no damage to the hull or rigging (boat was hauled and surveyed after the strike).

However, current still made its way down the sheath of the antenna coax and onto the negative side of the DC main bus. This pulse traveled through the DC system (on the negative side) and exited through the engine block that was connected to the inverter safety ground bond.

We lost every single piece of electronics and some of the electrics. The only things still working were the TV (plugged into a small inverter that was not switched on), the SSB (connected to a dedicated battery that is not part of the main house system), the battery monitor and the refrigerator (go figure...).

I have disassembled every component to look for damage or obvious avenues of repair.

The marine VHF and the autopilot computer were the only systems with visible component damage on their circuit boards. Anything containing logic circuits or computer control simply doesn't work anymore. Either it won't power up or powers up and reports gibberish or errors.

The current pulse is easily traced through the negative DC bus from the antenna coax shield. All fuses on the negative wires were blown apart while the fuses on the positive wires were OK (we have several ham radios on board with fuses on both wires). The inverter was on at the time and damaged, with the pulse getting on its metal case, traveling through the safety bond to the engine and out to water. The alternator on that engine lost its regulator, while the alternator on the other engine (not connected to the grounding system) was OK. When there was visible damage, the components blown on the circuit boards were universally diodes in places protecting from reverse polarity.

Two computers and various other equipment like cell phones, etc were plugged into the inverter when it was hit and suffered no damage. Many other small electronics like phones, handheld radio, two handheld gps's, two other computers, etc were lying around in the open not connected to anything and were not damaged. This points to the advice of putting things in the oven as possibly a wives tale.

In one cabinet was a router hooked to the house 12V power through a DC/DC converter, which was turned off at the main panel and two iPods - one connected to the inverter (I think) and one just lying in the cabinet unhooked to anything. A Ubiquity wifi system was also connected to the DC/DC converter through a POE connection. The router and both iPods were damaged - none of them would turn on. The DC/DC converter was toast. The Ubiquity system is OK. All of these items (except the Ubiquity) were within inches of each other and I believe the DC/DC converter created a localized EMP that took them out.

We have multiple other DC/DC converters on board powering stuff. They are all controlled at the main panel and none of them were switched on. All of them are internally shorted.

On the main panel, we lost a couple LED indicators and the DC ammeter. The DC voltmeter and AC volt and ammeter are OK.

Immediately after the strike, the ham radio turned itself on and tuned itself up at full volume. I turned it off. A few minutes later I noticed that it was very hot and pulled the power plug out of the back. Later, I found its fuse on its negative wire was blown, but the positive was OK. I replaced the fuse, but the radio never turned back on again. The coupler seems to be OK.

While grounding your radios may help, it will not contain the damage solely to the radio and antenna system like boasun suggests. A 100 tonner is a steel boat, which is about the best lightning protection system you can hope for, and explains the minimal damage he experienced.

I have talked to several people here who have been struck within the past two years. One reoccurring theme is that any components not damaged in the strike have been failing 6-12 months later.

I guess I will keep my eye on our battery monitor and reefer since they are the only things left running...

Mark

Did you have any aerial or lightning conductor on the masthead?

A lesson for us all here is if insured to demand everything electronic gets replaced, 6 months later for failures wouldn't be great.

[colemj]

Originally Posted by Lagoon4us

Did you have any aerial or lightning conductor on the masthead?

A lesson for us all here is if insured to demand everything electronic gets replaced, 6 months later for failures wouldn't be great.

No, the antenna was the highest point. We have two VHF antennas on the mast head. One was vaporized and the other is intact (don't know if it works yet).

I doubt many insurance companies will replace non-damaged gear - the list could be endless. However, you may want to negotiate holding your claim open for a period of time so that anything lost during that time can be argued to have been delayed damage.

Mark

[Richard Harper]

Originally Posted by Lagoon4us

Wow good post, do you know where the charge exited? ie prop shaft, earthing plate???

I think the main charge took the ground wire from the bottom of the mast directly down to the water. This connection was vaporized. None of the other wiring was damaged except the very small wires in the florescent lights but enough current came down the mast wiring to the fuse panel and from there to the various circuits. Open breakers did not prevent the nav lights from blowing out. Most of the damage on the breaker panel was around the breakers for the mast lights. The breakers themselves survived.

[colemj]

Originally Posted by Jon Hacking

We do not ground our rigging. My very casual & unscientific survey says that boats that do tend to have less damage, but also tend to get hit more often. With the electrical breakdown of air at 20KV/inch, I'd rather not have my mast at ground potential.

There are no actual data supporting that survey. Insurance companies would be demanding grounded/not grounded rigging if any real data biased even the least tiny bit toward either way. Lightning is at the very top of the payout claims.

Lightning following ionized trails to ground from miles up is not concerned about the last 50 or so feet. It all looks like an electrical ground from up there.

I would much rather protect the boat from serious, and potentially unrecoverable, structural damage than bet on a possible insignificant statistical advantage.

Mark