Car struck by lightning

[stuart]

This is now an ex Prius 

Stuart 

[Ian Vincent]

I guess that will have made a mess of the electronics.

Rgds Ian

[RogerH]

..not to mention his underpants....................

Edited April 14, 2022 by RogerH
typo

[stillp]

That gave him a rapid charge!

Pete

[john.r.davies]

2 hours ago, Ian Vincent said:

I guess that will have made a mess of the electronics.

Rgds Ian

Not so!    As you can see, the bodyshell is well insulated by the tyres, but the lightning strike has continued to the ground  via at least three wheels, as seen in the video.    But the shell forms a 'Faraday Cage' allowing no current and no electric field inside, protecting all the electronics.      

There are many, many records of aircraft struck by lightning - they do not crash!

And you may recall Richard Hammond's exepriment:

 

He drives away!

John

Edited April 14, 2022 by john.r.davies

[RobH]

3 minutes ago, john.r.davies said:

As you can see, the bodyshell is well insulated by the tyres,

Not quite so John. Tyres are actually slightly conductive - in the order of 1MOhm.  Quite high but sufficient to discharge static electricity from the shell to earth.  In any case, a lighting strike which has travelled some miles through air isn't going to be fazed by a couple of inches of rubber. 

The Faraday shield will protect the occupants but the flow of current through the body shell will induce a fast-rise current pulse in all the car wiring - and it is possible that this could damage sensitive electronics.  It is likely that manufacturers have recognised that risk and have included suitable surge-protection. 

[stuart]

Sorry John your wrong in this instance. The cars complete electric system was fried, its now scrap and on the thread on Twitter that clip was pulled from there were a lot of responses affirming that their vehicles having been struck had their electrics fried as well. Most were scrapped. The occupants were fine as they are insulated in the "Faraday Cage"

Stuart.

[john.r.davies]

I refer the  Honourable Members to my reply a few hours ago.   Mr.Hammond started and drove the car away.   Of course that was quite a long time ago, when Top Gear   was an interesting show and not taken over by rampant personalities, so maybe there was less 'sensitive electronics' in the car he used.   I'll bet that a Triumph would sail through the storm!

RobH, Tyre rubber contains carbon black doesn't it, so conducting.    You will have observed that the lightning just bypassed the tyres and jumped straight to  ground  with significant sparks, so not very conducting, as a MegOhm is one MILLION Ohms. 

John

[stuart]

27 minutes ago, john.r.davies said:

I refer the  Honourable Members to my reply a few hours ago.   Mr.Hammond started and drove the car away.   Of course that was quite a long time ago, when Top Gear   was an interesting show and not taken over by rampant personalities, so maybe there was less 'sensitive electronics' in the car he used.   I'll bet that a Triumph would sail through the storm!

 

That wasnt the same as a genuine lightning strike.

Stuart.

[SuzanneH]

1 hour ago, john.r.davies said:

I refer the  Honourable Members to my reply a few hours ago.   Mr.Hammond started and drove the car away.   Of course that was quite a long time ago, when Top Gear   was an interesting show and not taken over by rampant personalities, so maybe there was less 'sensitive electronics' in the car he used.   I'll bet that a Triumph would sail through the storm!

RobH, Tyre rubber contains carbon black doesn't it, so conducting.    You will have observed that the lightning just bypassed the tyres and jumped straight to  ground  with significant sparks, so not very conducting, as a MegOhm is one MILLION Ohms. 

John

Reminds me of a dilemma I had one Welsh Weekend camping beside a river in Rhayader. There was a tremendous storm and the ground I was supposed to be sleeping on was shaking, Roger was asleep/ too much beer. My dilemma whilst listening/ feeling the storm was to leave the tent and get in the car TR4A or stay put in the tent. I stayed put. My thoughts were exactly the same as the arguments here for and against being in the car. I wish I had gone and got in the car now……!!

[Ian Vincent]

I just Googled lightning strike and the following came up:

"A typical lightning flash is about 300 million Volts and about 30,000 Amps."

That's a bit more than the 800,000v that Top Gear used.

Rgds Ian

[Bleednipple]

14 minutes ago, Ian Vincent said:

I just Googled lightning strike and the following came up:

"A typical lightning flash is about 300 million Volts and about 30,000 Amps."

That's a bit more than the 800,000v that Top Gear used.

Rgds Ian

I know almost nothing about this subject (doesn't usually stop me) but isn't the reason that many people survive lightning strike that the impulse is extremely short duration even though high powered, so has little ability to heat up tissues even though it can do a lot of damage to cells? Would that also limit damage to wiring - potentially (ha, see what I did there?).

Nigel 

[Charlie D]

14 minutes ago, Bleednipple said:

...isn't the reason that many people survive lightning strike that the impulse is extremely short duration...

I have a feeling that the reason people survive lightening strikes is because the current flows over the outside of the body, especially if the person is wearing wet clothes.

It’s when it goes through the heart that you have a problem. I was taught to only ever touch bare wires with the back of my right hand so if the wire was live it may not end up sending the current through my heart.

I also have a recollection of being told that the first use of the electric chair in America was a failure for the same reason. The prisoner was sweating so much the current didn’t tough his internal organs.

Charlie.

[RobH]

No Nigel - being inside a metal enclosure means the current doesn't reach you.  It flows round through the metal.  That sets up a transient magnetic field but we don't feel that,  anymore than we feel anything when we pick up a magnet.  

People are only harmed when the current actually flows through their bodies.  Not only can you suffer burns but the current also interferes with the impulses in nerves. If it flows through your chest it can interrupt the pulses that drive your heart and cause fibrillation or cardiac arrest. That can happen if you are touching any of the affected metalwork and provide an alternative path for the strike.*

If there are wires running inside the metal shield they do see the influence of the magnetism which then induces a current in them. That's how generators and transformers work. The faster the change in the magnetic field the higher the resulting voltage in the wires.  It's the resulting voltage pulse that kills electronic devices since semiconductors are very sensitive to it.  They rely on insulating layers which can only withstand very low voltages before they break down. The drive to ever more complicated chips means each element is only nanometres thick.  It doesn't take much voltage to punch through that. 

 

* There are instances of cattle being killed by this.  A nearby lightning strike can result in very high currents flowing through the ground.  If cattle are close enough to the strike, the voltage difference between their front and rear legs can cause enough current to flow through their bodies to be fatal even though they have not been directly hit. 

Edited April 14, 2022 by RobH

[john.r.davies]

Few can claim to have survived beign struck by lightning.   I can't, but I did defibrillate myself once!

I was using a defibrillator, that passes a large charge through a victim's chest to stop ventricular fibrillation, in the hope that normal  contractions will restart, and the patient survive.     He did, but as I replaced the 'paddles' on the device, the old fashioned machine had recharged itself -they don't now because of this! - and I must have pressed the button.   About 200 KiloWatts of power were released into my hand that held the paddle, via the conductive jelly I had smeared on the patients chest.      Fortunately it also left my hand, via the metal rim of the device (also never used today).    

I felt as if a grenade had gone off in my hand, my arm was paralysed, temporarily, and I had to ask someone else to take over the resuscitation.   Because, as said above the charge didn't go from hand to hand across my heart, it wasn't affected (as far as I know).       But the hospital bush telegraph  got to work, and in the evening my friends were surprised to see me in the pub as by then I had had a cardiac arrest and was in ICU!  In fact, all I had was an  electrical burn on my knuckle!

John

[Dic Doretti]

          I had a girl friend who was struck by lightening while working as a vulcanologist on Mt Etna, she said it felt like a pat on the head! Her colleague saw it and suffered the biggest shock, he thought she must be dead. Probably saved by very wet clothing.

 

          Cheers Richard

[Tony_C]

2 hours ago, Charlie D said:

…… I was taught to only ever touch bare wires with the back of my right hand so if the wire was live it may not end up sending the current through my heart.

I also have a recollection of being told that the first use of the electric chair in America was a failure for the same reason. The prisoner was sweating so much the current didn’t tough his internal organs.

Charlie.

Hi Charlie,

Yep I was taught the same, mid to late 1970’s, but the primary reason for using the back of the hand was that electrical current sends a similar pulse as the brain clenching your fist. Therefore, you get ‘thrown away’ rather than clamped onto the current……..

And I remember being told that an electric ‘shock’ was something the body could never be conditioned to…. It would always remain a ‘shock’ (you can get used to bee stings for example…. But not a whole load of voltage going through you )