Rod Rigging - Hype?
 

http://www.sailnet.com/collections/a...eid=matthe0945

Rod rigging is more often used aboard racing boats than on cruising boats.
While an argument can be made for rod rigging lasting longer than wire
rigging, it won't take any kinks the way wire rigging will, which means one
ill-placed docking can mean the end of a shroud. And, there is no way to
inspect rod rigging short of x-ray, which presents the possibility of
surprise catastrophic failures. While rod rigging may last longer than wire,
it's somewhat of a moot point since the terminal ends will wear out before
the other components do.

Oh boy!

Amen!

Rod Rigging - Hype?
 

Rod rigging is more often used aboard racing boats than on cruising
boats.
While an argument can be made for rod rigging lasting longer than wire
rigging


In my research for my book I interviewed 5 surveyors in NY, PA and FL
who specialized in sailboats. ALL prefered rod rigging over traditional
wire. ALL felt that it's virtually impervious to failure, so long as
the fittings were updated and NONE had seen a failure and only two had
even heard of rod rigging rigs failing and in both cases it was
actually the chainplate that had failed! ALL had inspected rod rigged
boats from the early 80's that were found to be in excellent condition.
Of course my boat is not very old and her rigging is like new with
terminals updated in 2004.
Bob, it's best to actually do some real research instead of posting
superficial info from Sailnet that you coppied and pasted.

RB
35s5
NY

Rod Rigging - Hype?
 

Wouldn't it make sense to talk to a rigger about
rigging?
S.

"Capt. Rob" wrote in message
oups.com...
:
:
: In my research for my book I interviewed 5
surveyors in NY, PA and FL
: who specialized in sailboats. ALL prefered rod
rigging over traditional
: wire. ALL felt that it's virtually impervious to
failure, so long as
: the fittings were updated and NONE had seen a
failure and only two had
: even heard of rod rigging rigs failing and in
both cases it was
: actually the chainplate that had failed! ALL had
inspected rod rigged
: boats from the early 80's that were found to be
in excellent condition.
: Of course my boat is not very old and her
rigging is like new with
: terminals updated in 2004.
: Bob, it's best to actually do some real research
instead of posting
: superficial info from Sailnet that you coppied
and pasted.
:
: RB
: 35s5
: NY
:

Rod Rigging - Hype?
 

Only 5?

How many were licensed, professional engineers in the area of structures?

hmmm?

The only place rod rigging is used in structures is where the end could be
threaded, or bent and set in concrete. If it's swaged it's wire rope.

Yes, your guys saw failures - exactly the type of failures from using rod
rigging in that fashion.

Still don't get it, do you?

Think a bit...

Amen!



"Capt. Rob" wrote in message
oups.com...
Rod rigging is more often used aboard racing boats than on cruising
boats.
While an argument can be made for rod rigging lasting longer than wire
rigging


In my research for my book I interviewed 5 surveyors in NY, PA and FL
who specialized in sailboats. ALL prefered rod rigging over traditional
wire. ALL felt that it's virtually impervious to failure, so long as
the fittings were updated and NONE had seen a failure and only two had
even heard of rod rigging rigs failing and in both cases it was
actually the chainplate that had failed! ALL had inspected rod rigged
boats from the early 80's that were found to be in excellent condition.
Of course my boat is not very old and her rigging is like new with
terminals updated in 2004.
Bob, it's best to actually do some real research instead of posting
superficial info from Sailnet that you coppied and pasted.

RB
35s5
NY

Rod Rigging - Hype?
 

I have a hard time believing that rod rigging fails less than wire.
Consider, if a crack in a wire happens, it affects only that wire and
nothing comes down. ANY crack in rod rigging will quickly propogate
through the entire rod. Considering this, something is wrong with the
comparison.

Rod Rigging - Hype?
 

Bob Crantz wrote:
http://www.sailnet.com/collections/a...eid=matthe0945

Rod rigging is more often used aboard racing boats than on cruising boats.
While an argument can be made for rod rigging lasting longer than wire
rigging, it won't take any kinks the way wire rigging will, which means one
ill-placed docking can mean the end of a shroud. And, there is no way to
inspect rod rigging short of x-ray, which presents the possibility of
surprise catastrophic failures. While rod rigging may last longer than wire,
it's somewhat of a moot point since the terminal ends will wear out before
the other components do.

Oh boy!

Amen!


Rod rigging is also very difficult to store compared to a coil of wire rope.

Rod Rigging - Hype?
 

The cracks shown in that link are exactly like the ones I found in my
20 yr old rigging. The cracks in mine were very difficult to find
until I used fine sandpaper. They were all on the lower swaged end.
Most of the cracks were under small brown stains that were the result
of the stainless in the crack becoming non-stainless and rusting. They
required a 10X magnifier to find. At work, I ground the fittings away
to see how deep they went and they went through the entire fitting. I
even used dye penetrant with no luck. I replaced all the rigging and
lifelines last year.
NOW, although thefittings and wire and rod are stainless, stainless can
be slightly ferromagnetic and can be tested via flux leakage methods (I
used to do magnetic NDT research). Furthermore, the area around a
fatigue crack is less stainless and more ferromagnetic than the bulk
material. This may allow testing via mag particle inspection
(so-called magnafluxing). It is entirely that nobody has done this
because they simply assumed that teh stainless material wouldnt allow
this to work. Unfortunately, I threw the old rigging away so I cannot
try this.

Rod Rigging - Hype?
 

"Capt. Rob" wrote in message In my research for my book
I interviewed 5 surveyors in NY, PA and FL
who specialized in sailboats. ALL prefered rod rigging over traditional
wire.

Bwahahahahahahahahahahahaaaaaa!!!!!

Give it up Bob!

You own a Mac26X upgrade!

CM

Rod Rigging - Hype?
 

It fails immediately ...without warning ...and usually with catastrophic
results

CM.

wrote in message
ups.com...
I have a hard time believing that rod rigging fails less than wire.
Consider, if a crack in a wire happens, it affects only that wire and
nothing comes down. ANY crack in rod rigging will quickly propogate
through the entire rod. Considering this, something is wrong with the
comparison.

Rod Rigging - Hype?
 

Capt. Rob wrote:
Rod rigging is more often used aboard racing boats than on cruising
boats.
While an argument can be made for rod rigging lasting longer than wire
rigging


In my research for my book I interviewed 5 surveyors in NY, PA and FL
who specialized in sailboats. ALL prefered rod rigging over traditional
wire. ALL felt that it's virtually impervious to failure, so long as
the fittings were updated and NONE had seen a failure and only two had
even heard of rod rigging rigs failing and in both cases it was
actually the chainplate that had failed! ALL had inspected rod rigged
boats from the early 80's that were found to be in excellent condition.
Of course my boat is not very old and her rigging is like new with
terminals updated in 2004.
Bob, it's best to actually do some real research instead of posting
superficial info from Sailnet that you coppied and pasted.

RB
35s5
NY

In fact, regardless of whether you have rod or wire rope, there will be
failures but failures of either are rare. It is most often the rest of
the stuff that breaks. Inspections of rod rigging, by even the most
reputable of surveyors, is suspect because of the difficulty of finding
evidence of impending failure, unlike wire rope. While rod is stronger,
nicer looking and lighter, it is also more expensive, less user friendly
and spares are not normally kept onboard. It is therefore less
appealing to anyone but racers in pursuit of lighter faster boats and
prepared to accept the added cost, inconvenience and risk.

Gaz

Rod Rigging - Hype?
 

"NotPony" wrote in message
news:LrEuf.1732$Pe6.483@trnddc08...
Wouldn't it make sense to talk to a rigger about
rigging?
S.

In the martix, no.

John Cairns


"Capt. Rob" wrote in message
oups.com...
:
:
: In my research for my book I interviewed 5
surveyors in NY, PA and FL
: who specialized in sailboats. ALL prefered rod
rigging over traditional
: wire. ALL felt that it's virtually impervious to
failure, so long as
: the fittings were updated and NONE had seen a
failure and only two had
: even heard of rod rigging rigs failing and in
both cases it was
: actually the chainplate that had failed! ALL had
inspected rod rigged
: boats from the early 80's that were found to be
in excellent condition.
: Of course my boat is not very old and her
rigging is like new with
: terminals updated in 2004.
: Bob, it's best to actually do some real research
instead of posting
: superficial info from Sailnet that you coppied
and pasted.
:
: RB
: 35s5
: NY
:

Rod Rigging - Hype?
 

have a hard time believing that rod rigging fails less than wire.


As Gary pointed out, rigging failure is rare compared to a fitting or
chainplate cracking. That said, rod rigging is stronger and virtually
impossible to break, where wire does and has parted under sail. I'll
take the rod rigging every time thank you, especially on a boat in the
fine condition that mine is in. I also had rod on the C&C 32 and it was
bullet proof...really.

RB
35s5
NY

Rod Rigging - Hype?
 

It's not necessary for the material to be ferrous to do magnetic testing.
All it has to be is conductive. You can induce currents into the metal by
means of an electric field (and yes, it can have circulation ie it is
magnetic). The discontinuities in the induced current (due to cracks) will
cause a net increase in the responsive magnetic field (even though it is not
magnetic material - think - copper wire produces magnetic fields but it is
non ferrous) or changes in the E field on the surface of the metal. There
are films responsive to E fields, these can be used on the metal surface or
you can use small electric field probes.

You can even use the old standby of iron filings if you know what to look
for. I prefer RCS measurements to look for cracks.

Amen!



wrote in message
ps.com...
The cracks shown in that link are exactly like the ones I found in my
20 yr old rigging. The cracks in mine were very difficult to find
until I used fine sandpaper. They were all on the lower swaged end.
Most of the cracks were under small brown stains that were the result
of the stainless in the crack becoming non-stainless and rusting. They
required a 10X magnifier to find. At work, I ground the fittings away
to see how deep they went and they went through the entire fitting. I
even used dye penetrant with no luck. I replaced all the rigging and
lifelines last year.
NOW, although thefittings and wire and rod are stainless, stainless can
be slightly ferromagnetic and can be tested via flux leakage methods (I
used to do magnetic NDT research). Furthermore, the area around a
fatigue crack is less stainless and more ferromagnetic than the bulk
material. This may allow testing via mag particle inspection
(so-called magnafluxing). It is entirely that nobody has done this
because they simply assumed that teh stainless material wouldnt allow
this to work. Unfortunately, I threw the old rigging away so I cannot
try this.

Rod Rigging - Hype?
 

http://www.mac-ndt.com/app.cfm?App=2






wrote in message
ps.com...
The cracks shown in that link are exactly like the ones I found in my
20 yr old rigging. The cracks in mine were very difficult to find
until I used fine sandpaper. They were all on the lower swaged end.
Most of the cracks were under small brown stains that were the result
of the stainless in the crack becoming non-stainless and rusting. They
required a 10X magnifier to find. At work, I ground the fittings away
to see how deep they went and they went through the entire fitting. I
even used dye penetrant with no luck. I replaced all the rigging and
lifelines last year.
NOW, although thefittings and wire and rod are stainless, stainless can
be slightly ferromagnetic and can be tested via flux leakage methods (I
used to do magnetic NDT research). Furthermore, the area around a
fatigue crack is less stainless and more ferromagnetic than the bulk
material. This may allow testing via mag particle inspection
(so-called magnafluxing). It is entirely that nobody has done this
because they simply assumed that teh stainless material wouldnt allow
this to work. Unfortunately, I threw the old rigging away so I cannot
try this.

Rod Rigging - Hype?
 

http://www.ndtint.com/amigo.htm


wrote in message
ps.com...
The cracks shown in that link are exactly like the ones I found in my
20 yr old rigging. The cracks in mine were very difficult to find
until I used fine sandpaper. They were all on the lower swaged end.
Most of the cracks were under small brown stains that were the result
of the stainless in the crack becoming non-stainless and rusting. They
required a 10X magnifier to find. At work, I ground the fittings away
to see how deep they went and they went through the entire fitting. I
even used dye penetrant with no luck. I replaced all the rigging and
lifelines last year.
NOW, although thefittings and wire and rod are stainless, stainless can
be slightly ferromagnetic and can be tested via flux leakage methods (I
used to do magnetic NDT research). Furthermore, the area around a
fatigue crack is less stainless and more ferromagnetic than the bulk
material. This may allow testing via mag particle inspection
(so-called magnafluxing). It is entirely that nobody has done this
because they simply assumed that teh stainless material wouldnt allow
this to work. Unfortunately, I threw the old rigging away so I cannot
try this.

Rod Rigging - Hype?
 

Bob:

Yes, that is eddy current testing. I have not yet considered it. I'd
prefer to use mag particles (iron filings) as this does not require
runing a probe along all possible surfaces.

Rod Rigging - Hype?
 

How about sending an acoustic pulse along the rod rigging the same as a time
domain reflectometer works. The pulse speed is a property of material and
tension and the reflectance a function of acoustic impedance. Cracks would
raise the impedance. The cracks could be located along the length of the rod
by simply applying the pulse signal at one point.

http://www.tscm.com/riprcop.html




wrote in message
oups.com...
Bob:

Yes, that is eddy current testing. I have not yet considered it. I'd
prefer to use mag particles (iron filings) as this does not require
runing a probe along all possible surfaces.

Rod Rigging - Hype?
 

Cracks would
raise the impedance. The cracks could be located along the length of
the rod
by simply applying the pulse signal at one point.

Seems to me that for this to work well you'd need to remove the rod
from the boat and tension it is some sort of way, equally. Then you
might read cracks, but be unable to actually locate them, meaning a
small non-dangerous imperfection in the rod might give a false reading.
Seems like a tool that would get abused to sell a lot of uneeded
rigging..
Just about every rig failure I've ever heard of was wire. While I'm
sure rod has failed....I've never heard of it. Anyone know of a rod
rigging failure they can point to online? I'm too sleepy to google
today.

RB
35s5
NY

Rod Rigging - Hype?
 

Bob Crantz wrote:

How about sending an acoustic pulse along the rod rigging the same as a time
domain reflectometer works. The pulse speed is a property of material and
tension and the reflectance a function of acoustic impedance. Cracks would
raise the impedance. The cracks could be located along the length of the rod
by simply applying the pulse signal at one point.

Sounds good to me, I don't belive tension (or compression) has anything
to with the speed of transmission in a solid.

Cheers
Marty

Rod Rigging - Hype?
 

Rob:

You don't have to remove the rigging at all. On the TDR pulse you can easily
see the where the spreader touches to rod, you can run your hand up and down
the rod and see its location on the TDR. Since sound waves don't propagate
through cracks, the sound energy would be reflected back at the source and
the location of the crack could easily be identified.

All you need is a good piezo transducer that transmits and receives, a pulse
generator (a simple circuit) and some display like an oscilloscope. You can
even make a display on a laptop. With some signal processing you could
really do some great analysis of the rigging.

Think of a sonar with metal instead of water as the medium. One could even
spot cracks and corrosion in the end fittings. Also think of a musical
instrument. If the fret or neck on a guitar is damaged, it is easy to hear.
These same principals apply to the TDR.

Amen!

"Capt. Rob" wrote in message
oups.com...
Cracks would
raise the impedance. The cracks could be located along the length of
the rod
by simply applying the pulse signal at one point.

Seems to me that for this to work well you'd need to remove the rod
from the boat and tension it is some sort of way, equally. Then you
might read cracks, but be unable to actually locate them, meaning a
small non-dangerous imperfection in the rod might give a false reading.
Seems like a tool that would get abused to sell a lot of uneeded
rigging..
Just about every rig failure I've ever heard of was wire. While I'm
sure rod has failed....I've never heard of it. Anyone know of a rod
rigging failure they can point to online? I'm too sleepy to google
today.

RB
35s5
NY

Rod Rigging - Hype?
 

Sounds good to me, I don't belive tension (or compression) has anything

to with the speed of transmission in a solid.

But to get the expected measurements in a solid structure that is being
read for resonent feedback variances, wouldn't said feedback be
effected if the the solid had a wide range of motion? Seems like it
would require isolation for relaible readings. Out of my depth on this
one, folks....just guessing based on what I've read from Bob C.

RB
35s5
NY

Rod Rigging - Hype?
 

"Martin Baxter" wrote in message
...

Sounds good to me, I don't belive tension (or compression) has anything
to with the speed of transmission in a solid.


Assume a completely rigid guitar neck. Adjusting the tension of the string
adjusts its resonant frequency. If the length does not change, but the
resonant frequency does, then the velocity in the string must change.

C = tension/linear density

http://www.faqs.org/docs/sp/sp-172.html

Rod Rigging - Hype?
 

Bob Crantz wrote:

"Martin Baxter" wrote in message
...

Sounds good to me, I don't belive tension (or compression) has anything
to with the speed of transmission in a solid.

Assume a completely rigid guitar neck. Adjusting the tension of the string
adjusts its resonant frequency. If the length does not change, but the
resonant frequency does, then the velocity in the string must change.

C = tension/linear density

I don't think so, you are thinking of resonance in a transverse plane,
not propagation of a sound wave through the medium. Your example is for
a transverse wave, the TDR mode you propose to employ is in fact a
compresion/rarefaction, not unlike the P wave in siesmology. The problem
is going to be "injecting" this pulse, if you just tap the side of the
rod you will generate transverse waves rather than the longitudinal wave
you are seeking. I do not think that that transverse waves will be
reflected by a crack in the rod or the connectors between rod sections.

See http://prola.aps.org/abstract/PRD/v7/i6/p1590_1 for the general
equation.


Cheers
Marty

Rod Rigging - Hype?
 

Bob Cranz is correct, this would work for cracks in the rod, even when
it was attached at both ends. When rod fails, where does it fail, I'd
bet at the ends where TDR would be harder.
Given identical types of ends and repeatedly stressed, any engineer
would expect that solid rod would fail before cable type. A crack in a
single strand of wire cannot propogate anywhere except in that strand.
A crack in solid can go all the way through and probably will because
the crack itself becomes a stress concentrator.

Rod Rigging - Hype?
 

Given identical types of ends and repeatedly stressed, any engineer
would expect that solid rod would fail before cable type.


This guy is a funny troll. Even the makers of standing rigging admit
that rod is more durable. It's also a supperior system due to lower
weight. Just take care of it. Surveyors who have no market interest in
selling either also say rod is longer lived.
This guy is some engineer.

RB
35s5
NY

Rod Rigging - Hype?
 

You are right Marty, it is the case of S and P waves in geology. They travel
at two different velocities, both dependent on tension.

The TDR wants the P wave. Inducing an S wave will cause a P wave. The S wave
can be damped by putting clay on the rod to reduce transverse vibration.

The two waves can be separated by their velocities and the design of the
receiver transducer. If the receiver transducer is sensitive to only axial
forces, then it will see only P type waves. Likewise for the transmit
transducer. If it can displace only axially wrt to the rod, everything is
ok.

Good job on catching the distinction. A fine point that only a learned,
diligent man such as yourself would catch.

Try this link:

http://quake.wr.usgs.gov/research/ph...shearwave.html

Note they can measure cracks too.


Amen!

"Martin Baxter" wrote in message
...
Bob Crantz wrote:

"Martin Baxter" wrote in message
...

Sounds good to me, I don't belive tension (or compression) has anything
to with the speed of transmission in a solid.

Assume a completely rigid guitar neck. Adjusting the tension of the
string
adjusts its resonant frequency. If the length does not change, but the
resonant frequency does, then the velocity in the string must change.

C = tension/linear density

I don't think so, you are thinking of resonance in a transverse plane,
not propagation of a sound wave through the medium. Your example is for
a transverse wave, the TDR mode you propose to employ is in fact a
compresion/rarefaction, not unlike the P wave in siesmology. The problem
is going to be "injecting" this pulse, if you just tap the side of the
rod you will generate transverse waves rather than the longitudinal wave
you are seeking. I do not think that that transverse waves will be
reflected by a crack in the rod or the connectors between rod sections.

See http://prola.aps.org/abstract/PRD/v7/i6/p1590_1 for the general
equation.


Cheers
Marty

Rod Rigging - Hype?
 

Bob Cranz:

Do you do NDT?
(Non-Destructive Testing)

Rod Rigging - Hype?
 

Not primarily, electromagnetics R&D. DC - Millimeter Wave, IR-visible. Lots
of sensor work.

Amen!




wrote in message
oups.com...
Bob Cranz:

Do you do NDT?
(Non-Destructive Testing)

Rod Rigging - Hype?
 

Cool, I used to do some IR sensor work on Star Wars, now I do x-ray
optics.

Rod Rigging - Hype?
 

Bob Crantz wrote:



Good job on catching the distinction. A fine point that only a learned,
diligent man such as yourself would catch.

Try this link:

http://quake.wr.usgs.gov/research/ph...shearwave.html



Well shucks, thanks. Let's patent this idea PDQ, must be tens of dollars
to be made selling this gizmo to budding marine surveyors!

Cheers
Marty