YOU'VE BEEN THUNDERSTRUCK !!

[DESIREMK1]

Hi Guy's ,

Just wondering what effects your Top Hats suffer , after being hit by lightning ?? ,

Back in Easter 1992 I almost died at Del Rio Riverside Resort which is at Wisemans Ferry , on the Hawkesbury River , from almost being struck by lightning . Being 19 at the time I was standing down by the river with slight thunder rumbling in the background , when all of a sudden , without prior warning I saw what could only described as a brilliant flash of light , much like a Flourescent Tube that I could not see to the sides of ( imagine a picture if take from 50m behind me of the incident ) . The most amazing clasp of thunder followed , in fact it was so loud that the Resort Kiosk worker dropped to the floor in fright . with me scampering back to my parents caravan , and leaving my Diamond Back BMX at the waters edge . after my cousins came back from there Waterski run with their father , they were curious as to why I left my BMX at the waters edge and I was no where to be seen ( hiding in my parents caravan - lol ) , as I was also due to be the next Waterskiier ...

Certainly a life changing event in an instant , it could have been . So I imagine with the Mast on sailboats such as Top Hats , they would become an attractive earthing point for a waywood bolt out of the blue ....

Brad
DESIREMK1

[SeaLady]

My Top Hat has never been hit by lightening.
However I have been on board during spectacular lightening storms.
Some very close hits.

No problems... yet

[Troppo]

I think I have a sensible strategy, not that I have needed to use it. Many years ago I was watching some young kids playing cricket next door. In the rain. Thunder rumbling. Suddenly there was a big clap of thunder right overhead. "Down!" yelled the leader of the boys and they all dived to the ground. None of them were killed by lightning so I guess that diving to the ground when you hear thunder means you duck any lightning flying around. Hmm, being out on a boat is a bit of a problem as it would take a little while to get to shore to find some ground to dive onto and escape bolts of electricity being fired at you. Maybe diving down into the bilge might be a reasonable substitute. Any Benjamin Franklins around who want to experiment?

Troppo

[Dolphin]

Yes Brad, Good question considering summer is a way off.
Felicite suffered during a summer of reasonably high lightning activity.
There are three types of lightning strike, a direct hit, leaders and induction strikes.
The direct hit is what you experienced and you're really lucky if you survive it.

THe second type, a leader is the precurser to a direct hit. It's where a corona is started from any object and the air is starting to break down electrically. You can sometimes see it as a pinkish line just before the lightning follows it to the ground. The cricketers were lucky but the wrong strategy. If it was dark you may have seen the corona or leaders coming from sharp objects. It usually appears well before the rain starts, as the Anvil head of the storm cloud passes over, it has the highest electrical stress. Usually you can see peoples hair start to stand up, that is the time to hit the deck. Laying in the ground is the most dangerous thing to do. If lightning hits nearby, the voltage drop through the ground is high and can be enough to kill you. You should crouch down with your feet together.

The third type is an induction strike. The current in the lightning can be 10,000 amps and it rises in 1.5 microseconds and decays relatively slowly in about 50 microseconds. This induces large voltages in ANY metal objects and wiring nearby. You don't actually have to be hit by the lightning for it to cause damage.
Felicite suffered damage from I think an induction strike. The Log, an Autohelm ST50 instrument started to do wierd things after one of the storms. As the votage of the battery charged up, the meter would go into alarm, give wierd readings etc. It was traced back to the 5 Volt regulator that had broken down and was allowing 12 V to the 5V system. Other instruments started to play up after that too. THe induction strike can blow away sections of the semiconductor and render the junction incapable of carrying the current. Sometime 50V is all it takes at the semiconductor. Electronic equipment may fail months after a strike.
A boat was hit in Burraneer bay and sunk as the lightning went all the way through the wiring and blew the depth sounder transducer to bits and sunk the boat.
Some friend were returning to Sydney from Lord Howe Is and they suffered a direct hit on the mast head. They saw the flash but didn't hear any sound. They lost instruments and the alternator. That was on a Roberts Spray called "Florescent".
In Europe there are 10 people killed per year on boats.
When there are storms around, I put a piece of chain from the bottom of the cap shroud and drop it into the water. It might save the lightning tracking across the deck and burning it. The safest place to be in an electrical storm is in a car. The body acts as a Faraday Shield.

Nothing will stop a direct strike.

Hope it helps.

[Phillip]

Well said Greg,

Last year when I got caught off Ballina in an electrical storm I disconnected my radio from the power, earth and aerial. I contacted VMR Ballina before I did it and they were calling me when I was clear of the storm and had the radio back up and running!

They sounded anxious too.

[DESIREMK1]

Hi Gentlesalts ,

As much as I love the weather elements , sailing at the time of a harsh thunder storm with lightening in the vicinity would certainly create a sense of anxiety . In the past I have been through numerous storm events , while waterskiing and driving for skiers , on one occurrence driving for a skier at Sackville Gardens ( Hawkesbury River ) I was awestruck to see where a bolt hit a tree on the side of the river and momenterally caught the tree on fire . Though I imagine in the peace and serenity of a lovely Top Hat , the sailing environment would be left in awe of Mother Natures brutality due to the amplication of the quietness .....


Have a great weekend sailing , I would love to be with you in most conditions ( lol )

Brad
DESIREMK1

[storm petrel]

We met the owner of Peppercorn a few years back. He got Peppercorn a Mk11 Top Hat for a song because it had been holed by lightning on it's mooring and sunk up the Hawkesbury River. The insurers wrote the boat off, raised it and the Insurance company sold it for less than $1000 just to get rid of it.
There are pictures of it on the site somewhere because it came to the get together at the CYCA few years back.

I also connect a chain from the rigging to the water when sailing in thunderstorms, but I have never worried about the boat on the mooring.

Mark
Storm Petrel

[DESIREMK1]

Hi Mark ,

I bet half the battle with raising Peppercorn from the depth of the Hawkesbury River was due to the added weight of mud that would have accumulated within the hull , as my families BB Chev Raceboat went through the 1991 Hawkesbury River Floods as it was stored alongside our caravan at the time . When I bought the boat of my older brother , I eventually pulled the engine out to be rebuilt . During which time I took off the Mallory inlet manifold to find a contoured piece of dried mud , given the countless hours skiing and driving around Wisemens Ferry , I am aware of BB Chevs durability . Would love to know how flooded it made Pittwater and surrounds as our van was swamped up to the roof line - across the valley flood height ...

Brad
DESIREMK1

[Tales]

Some books by offshore sailors recomend wrapping portable equipment in aluminum foil
(hand held GPS, radio and quick detach instruments - Tacktick) or put inside microwave oven.

They also claim that it has inertia and wants to keep traveling the same direction ie it may travel down a mast or shroud but keep going even with a strap bolted on at right angles.

Cheers,

Tom

[storm petrel]

I think it is more likely to follow the path of least resistance and that is why a lot of bigger boats have the highest metal object on the boat connected to the water via a thick copper strip. Chain may not be ideal, but at least it will provide a parallel path for any current heading down from the top of the mast. Putting electronics in a metal box (Faraday cage) will protect them, provided they are not connected to any leads that go outside the box. We used to enclose the CROs to protect them when I used to work with high voltage (20,000V +) pulsed lasers.