"Urban Legend" information

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1

Posted by lance_ryley (lance_ryley@…>)

Here’s a response I got from Don Casey on the subject:

Dear Lance Ryley,

You recently submitted a question to BoatUS expert Don Casey: Do-It-
Yourself Guru. Our expert had a chance to review your question and has
provided an answer:

Your original question:
Hi Don,
I just finished your boat electrics book from cover to cover and am
about to start work, esp. on my shore system. I live on a Freedom 40
Cat Ketch with free-standing carbon masts, and wanted your take on
lightning and carbon fiber, and also the cone of protection as it
pertains to split-rig vessels.

Thanks,
Lance Ryley
Bright Star

Our expert’s answer:
Since carbon fiber is an indifferent conductor, some other conductor
is required to safely get a lightning strike to ground. The carbon
masts on Freedoms have a lightning rod at the truck connected to a #4
cable in the mast laminate. The lower end of the cable is connected to
a ground plate on the outside of the hull. If your Freedom is set up
this way, you and your crew should be protected from lightning strike.
If you do not have a conductor connected to ground, the mast will not
provide reliable protection.



The “cone of protection” scribes a circle at water level with a radius
approximately equal to the height above the water of the grounded
lightning rod. That means that cone associated with either mast should
include the entire boat. Having two masts does not lessen your
protection. Each functions individually—assuming both are grounded.
Lightning will prefer the shorter leap to the masthead.



If you do have the misfortune of a direct hit, your mast is likely to
suffer. You should have an ultrasonic and/or a bend test performed.
Repairing a lightning-damaged carbon spar is usually not cost-
effective. If the tests reveal damage, you will need a new spar.

— In freedomyachts2003@yahoogroups.com, “williedoylemom”
<williedoylemom@y…> wrote:

A friend told me that if lightening hits a carbon fiber mast it will
destroy the core. You won’t know if this has happened until some
stress is put on the mast and then it will just buckle. I’ve
researched this on Google and cannot confirm it. Does anyone know
if
something like this? Or is it just an urban myth. We are considering
buying a Freedom 35, looking at some here in Florida now. We’d like
to know if this is something we should watch out for. Thank you,
Faith

www.faithandrewsbedford.com

2

Posted by katorpus (katorpus@…>)

Interesting observations, Lance…with one correction.

My particular Freedom 40 Cat Ketch is hull #61 (of 63 built), and,
having personally supervised the peeling of the gelcoat down to the
first layer of mat (below the waterline), I can assure you that I
don’t recall any external grounding plates. It would have a very
evident termination on the INSIDE of the hull…somewhere. If
anybody’s boat has one, this is something which would be left
unpainted, and ought to be pretty obvious any time the boat is
hauled.

The wires at the base of my masts are tied into the rest of the
bonding system on the boat…bronze thru hulls, shaft etc.




— In freedomyachts2003@yahoogroups.com, “lance_ryley”
<lance_ryley@y…> wrote:

Here’s a response I got from Don Casey on the subject:

Dear Lance Ryley,

You recently submitted a question to BoatUS expert Don Casey: Do-
It-
Yourself Guru. Our expert had a chance to review your question and
has
provided an answer:

Your original question:
Hi Don,
I just finished your boat electrics book from cover to cover and
am
about to start work, esp. on my shore system. I live on a Freedom
40
Cat Ketch with free-standing carbon masts, and wanted your take on
lightning and carbon fiber, and also the cone of protection as it
pertains to split-rig vessels.

Thanks,
Lance Ryley
Bright Star

Our expert’s answer:
Since carbon fiber is an indifferent conductor, some other
conductor
is required to safely get a lightning strike to ground. The carbon
masts on Freedoms have a lightning rod at the truck connected to a
#4
cable in the mast laminate. The lower end of the cable is
connected to
a ground plate on the outside of the hull. If your Freedom is set
up
this way, you and your crew should be protected from lightning
strike.
If you do not have a conductor connected to ground, the mast will
not
provide reliable protection.

The “cone of protection” scribes a circle at water level with a
radius
approximately equal to the height above the water of the grounded
lightning rod. That means that cone associated with either mast
should
include the entire boat. Having two masts does not lessen your
protection. Each functions individually—assuming both are
grounded.
Lightning will prefer the shorter leap to the masthead.

If you do have the misfortune of a direct hit, your mast is likely
to
suffer. You should have an ultrasonic and/or a bend test
performed.
Repairing a lightning-damaged carbon spar is usually not cost-
effective. If the tests reveal damage, you will need a new spar.

— In freedomyachts2003@yahoogroups.com, “williedoylemom”
<williedoylemom@y…> wrote:

A friend told me that if lightening hits a carbon fiber mast it
will
destroy the core. You won’t know if this has happened until
some
stress is put on the mast and then it will just buckle. I’ve
researched this on Google and cannot confirm it. Does anyone
know
if
something like this? Or is it just an urban myth. We are
considering
buying a Freedom 35, looking at some here in Florida now. We’d
like
to know if this is something we should watch out for. Thank you,
Faith

www.faithandrewsbedford.com

3

Posted by lance_ryley (lance_ryley@…>)

Hi,
My hull is 49, and I’m sure it is not grounded in the way described
in my previous post - I assume it’s something they added in later
designs. I think your point is well taken that basically no one
knows what attracts lightning, and that strikes are still
exceedingly rare, which is good news!

I haven’t decided what I’m going to do about my own masts yet, but
I’m not overly concerned that I’m in any danger.

Merry Christmas and Happy New Year to all of you and your families
Lance and Pam Ryley
Bright Star
— In freedomyachts2003@yahoogroups.com, “katorpus” <katorpus@y…>
wrote:

Interesting observations, Lance…with one correction.

My particular Freedom 40 Cat Ketch is hull #61 (of 63 built), and,
having personally supervised the peeling of the gelcoat down to
the
first layer of mat (below the waterline), I can assure you that I
don’t recall any external grounding plates. It would have a very
evident termination on the INSIDE of the hull…somewhere. If
anybody’s boat has one, this is something which would be left
unpainted, and ought to be pretty obvious any time the boat is
hauled.

The wires at the base of my masts are tied into the rest of the
bonding system on the boat…bronze thru hulls, shaft etc.

— In freedomyachts2003@yahoogroups.com, “lance_ryley”
<lance_ryley@y…> wrote:

Here’s a response I got from Don Casey on the subject:

Dear Lance Ryley,

You recently submitted a question to BoatUS expert Don Casey: Do-
It-
Yourself Guru. Our expert had a chance to review your question
and
has
provided an answer:

Your original question:
Hi Don,
I just finished your boat electrics book from cover to cover and
am
about to start work, esp. on my shore system. I live on a
Freedom
40
Cat Ketch with free-standing carbon masts, and wanted your take
on
lightning and carbon fiber, and also the cone of protection as
it
pertains to split-rig vessels.

Thanks,
Lance Ryley
Bright Star

Our expert’s answer:
Since carbon fiber is an indifferent conductor, some other
conductor
is required to safely get a lightning strike to ground. The
carbon
masts on Freedoms have a lightning rod at the truck connected to
a
#4
cable in the mast laminate. The lower end of the cable is
connected to
a ground plate on the outside of the hull. If your Freedom is
set
up
this way, you and your crew should be protected from lightning
strike.
If you do not have a conductor connected to ground, the mast
will
not
provide reliable protection.

The “cone of protection” scribes a circle at water level with a
radius
approximately equal to the height above the water of the
grounded
lightning rod. That means that cone associated with either mast
should
include the entire boat. Having two masts does not lessen your
protection. Each functions individually—assuming both are
grounded.
Lightning will prefer the shorter leap to the masthead.

If you do have the misfortune of a direct hit, your mast is
likely
to
suffer. You should have an ultrasonic and/or a bend test
performed.
Repairing a lightning-damaged carbon spar is usually not cost-
effective. If the tests reveal damage, you will need a new spar.

— In freedomyachts2003@yahoogroups.com, “williedoylemom”
<williedoylemom@y…> wrote:

A friend told me that if lightening hits a carbon fiber mast
it
will
destroy the core. You won’t know if this has happened until
some
stress is put on the mast and then it will just buckle. I’ve
researched this on Google and cannot confirm it. Does anyone
know
if
something like this? Or is it just an urban myth. We are
considering
buying a Freedom 35, looking at some here in Florida now.
We’d
like
to know if this is something we should watch out for. Thank
you,
Faith

www.faithandrewsbedford.com