Hi NiceAft,
So no one wants to be called “Sparky” right?
I think JimmyT (and the others) has the right idea in not working around anything metal and tall within a couple miles of a
lightning storm.
By the time you see-it/hear-it “it’s” too close (IMO).
Time to stay away!
In the Marina lowering the mast from the mast pivot plate would have the top of the mast in the slipway and pose a possible hazard to others safe operation.
Statistical Odds are pretty darn low that any one individual boat gets hit by
lightning.
So there is that to have some comfort in.
The challenge from my perspective is not the lighting hitting a particular boat but the subsequent Electro Magnetic Pulse (EMP) that will affect every boat’s electronics particularly if there is a length of conductor connected to it ( which is just about everything connected to power or antenna or unplugged wire length connected to a device (think of the wire between a switch to the device).
What? Yup, just about all of it is susceptible to an EMP.
What determines IF there is damage is a whole bunch of seemingly random aspects such as distance from strike (the EMP effect decays at roughly the square of the distance (meaning it decays quickly the further away from the strike), the length of the conductor connected (the longer the conductor the more it picks up), the frequency of the pulse (
lightning is actually a rapid series of pulses at no set frequency per-se), and earth ground potential.
From an Engineering perspective when confronted with an impending
lightning event and valuable or difficult to replace electronics is to do is to:
1) Turn off and physically disconnect all devices from power and antennas
2) Where possible (like with our Garmin GPS chartplotter and VHF Radio) we remove it from the boat and bring it (home) with us.
3) Install fuses or circuit breakers at or below the rated amperage for the device (yes there may be nuisance trips but the lower the fuse or breaker trips the better)
While there are lighting surge
protection devices such as one would put in your home AC electrical panel but those require a hard ground connection to work and would only apply is you had an AC power connection to shore power but that would only protect you from a EMP surge coming from the shore power source, not from an EMP sensed onboard.
There are some
lightning suppression systems that attempt to actively balance out the electrical charge potential between the vessel and atmosphere. (Lighting is static electricity and can be earth positive-sky negative or vice versa.) How a system would actively sense a local build up of charge potential fast enough to activate and then be able to locally reverse or dissipate it is beyond me.
There are great passionate theoretical arguments for and against “grounding” ones mast to the water via chains from the stay cables.
From a Design Engineering perspective
lightning is a lot of voltage and a lot of amperage at the same time pretty much all at once.
The cables are SST (not a stellar conductor and there are at least four connections with about 6 cables) and the mast is aluminum (great conductor almost as good as copper). “IF” one were to ground I would be inclined to ground directly at the mast with a ‘O’ gauge copper cable several yards deep in the water. BUT DOING THIS WOULD MAKE YOUR MAST “THE PREFERRED LOCAL TARGET”.
So that means yours is the target and your stuff is closest to the EMP source.
So, clear as mud huh?
Which is why we prefer to disconnect and remove.
Stay safe or if you prefer should we start calling you “Sparky”? or “Sparks”? or “Sparkles?” or “Tingle Toes”? or “Twinkle”? or “Zap”? or …….
