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  #21   Report Post  
Rufus
 
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Default Technique for avoiding collision with floating debris......

For boats w/out a bowsprit, a good thick strip of SS, say 3/16 x 1 (or
1-1/2), running down the stem from below the forestay fitting to the
curve of the forefoot would help reduce damage. Would also help when
indulging in a little "Chicago parking" into concrete docks at a couple
knots... g

Bowsprits usually have a stay (correct name escapes me at the moment)
down to the water line. In this case you could run the SS strip from the
lower end of the stay down the forefoot, but if you charged into
anything above the water, you'd catch 'sprit stay. Probably the strip
would still help, though.

Rufus

Jeff Morris wrote:
Avoidance strategies might reduce the odds of collision somewhat, but not enough to
consider the risk eliminated. Radar, for instance, might work in some conditions, but not
all.

This leaves two approaches: one, which has been discussed, is preparing to handle the
damage efficiently. I'd be curious what percentage of collision damages event can be
handled with a collision mat, and how many required abandoning ship. Clearly, when the
damage is too severe, most vessels will sink like the proverbial stone, but there are
certain levels of damage where a mat will save the day.

The third approach is to reduce the odds of the vessel sinking, with positive floatation
and/or collision bulkheads. Multihulls have an advantage, since they don't have the dead
weight of the keel, and the hulls are shaped to facilitate flotation chambers. But any
relatively light vessel can be made reasonably unsinkable. One can make a case that
floatation bags are a better investment than a liferaft.



  #22   Report Post  
Daniel E. Best
 
Posts: n/a
Default Technique for avoiding collision with floating debris......

It's frequently called the "Bob Stay" - dunno who bob is/was.

I've always wondered why they didn't mold 6" worth of bumber along the
stem out of that same high density rubber they make auto bumbers out
of. It could be faired into the hull so that it would have a minimal
effect on drag. My understanding is that by distributing the impact
onto perhaps a square foot of the strongest portion of the hull, it
would prevent major damage when striking the object with the stem (which
I assume would be the most likely initial point of contact, as opposed
to a glancing blow along the topsides or some such.
- Dan

Rufus wrote:

For boats w/out a bowsprit, a good thick strip of SS, say 3/16 x 1 (or
1-1/2), running down the stem from below the forestay fitting to the
curve of the forefoot would help reduce damage. Would also help when
indulging in a little "Chicago parking" into concrete docks at a
couple knots... g

Bowsprits usually have a stay (correct name escapes me at the moment)
down to the water line. In this case you could run the SS strip from
the lower end of the stay down the forefoot, but if you charged into
anything above the water, you'd catch 'sprit stay. Probably the strip
would still help, though.

Rufus

Jeff Morris wrote:

Avoidance strategies might reduce the odds of collision somewhat, but
not enough to
consider the risk eliminated. Radar, for instance, might work in
some conditions, but not
all.

This leaves two approaches: one, which has been discussed, is
preparing to handle the
damage efficiently. I'd be curious what percentage of collision
damages event can be
handled with a collision mat, and how many required abandoning ship.
Clearly, when the
damage is too severe, most vessels will sink like the proverbial
stone, but there are
certain levels of damage where a mat will save the day.

The third approach is to reduce the odds of the vessel sinking, with
positive floatation
and/or collision bulkheads. Multihulls have an advantage, since they
don't have the dead
weight of the keel, and the hulls are shaped to facilitate flotation
chambers. But any
relatively light vessel can be made reasonably unsinkable. One can
make a case that
floatation bags are a better investment than a liferaft.




--
Dan Best - (707) 431-1662, Healdsburg, CA 95448
B-2/75 1977-1979
Tayana 37 #192, "Tricia Jean" http://rangerbest.home.comcast.net/TriciaJean.JPG

  #23   Report Post  
Daniel E. Best
 
Posts: n/a
Default Technique for avoiding collision with floating debris......

It's frequently called the "Bob Stay" - dunno who bob is/was.

I've always wondered why they didn't mold 6" worth of bumber along the
stem out of that same high density rubber they make auto bumbers out
of. It could be faired into the hull so that it would have a minimal
effect on drag. My understanding is that by distributing the impact
onto perhaps a square foot of the strongest portion of the hull, it
would prevent major damage when striking the object with the stem (which
I assume would be the most likely initial point of contact, as opposed
to a glancing blow along the topsides or some such.
- Dan

Rufus wrote:

For boats w/out a bowsprit, a good thick strip of SS, say 3/16 x 1 (or
1-1/2), running down the stem from below the forestay fitting to the
curve of the forefoot would help reduce damage. Would also help when
indulging in a little "Chicago parking" into concrete docks at a
couple knots... g

Bowsprits usually have a stay (correct name escapes me at the moment)
down to the water line. In this case you could run the SS strip from
the lower end of the stay down the forefoot, but if you charged into
anything above the water, you'd catch 'sprit stay. Probably the strip
would still help, though.

Rufus

Jeff Morris wrote:

Avoidance strategies might reduce the odds of collision somewhat, but
not enough to
consider the risk eliminated. Radar, for instance, might work in
some conditions, but not
all.

This leaves two approaches: one, which has been discussed, is
preparing to handle the
damage efficiently. I'd be curious what percentage of collision
damages event can be
handled with a collision mat, and how many required abandoning ship.
Clearly, when the
damage is too severe, most vessels will sink like the proverbial
stone, but there are
certain levels of damage where a mat will save the day.

The third approach is to reduce the odds of the vessel sinking, with
positive floatation
and/or collision bulkheads. Multihulls have an advantage, since they
don't have the dead
weight of the keel, and the hulls are shaped to facilitate flotation
chambers. But any
relatively light vessel can be made reasonably unsinkable. One can
make a case that
floatation bags are a better investment than a liferaft.




--
Dan Best - (707) 431-1662, Healdsburg, CA 95448
B-2/75 1977-1979
Tayana 37 #192, "Tricia Jean" http://rangerbest.home.comcast.net/TriciaJean.JPG

  #24   Report Post  
Rufus
 
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Rufus
 
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  #26   Report Post  
Doug Dotson
 
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Default Technique for avoiding collision with floating debris......

Bumber? Most boats aren't designed with the assumption that
the captain runs into thing all the time. When a collision does occur,
it is not always straight on. The few times I have bumped on a
log or other junk, it wasn't head on, but rather hit me along the
sides. If it had been a container, it would have probably pierced
the hull along the forward quarters. It is possible to build a boat
like a tank, but it would be expensive and sail like the Merrimac
or Monitor.

Doug

ps. That would be "Bobstay" or "Robertstay"

"Daniel E. Best" wrote in message
news:wgAvb.271838$Fm2.285478@attbi_s04...
It's frequently called the "Bob Stay" - dunno who bob is/was.

I've always wondered why they didn't mold 6" worth of bumber along the
stem out of that same high density rubber they make auto bumbers out
of. It could be faired into the hull so that it would have a minimal
effect on drag. My understanding is that by distributing the impact
onto perhaps a square foot of the strongest portion of the hull, it
would prevent major damage when striking the object with the stem (which
I assume would be the most likely initial point of contact, as opposed
to a glancing blow along the topsides or some such.
- Dan

Rufus wrote:

For boats w/out a bowsprit, a good thick strip of SS, say 3/16 x 1 (or
1-1/2), running down the stem from below the forestay fitting to the
curve of the forefoot would help reduce damage. Would also help when
indulging in a little "Chicago parking" into concrete docks at a
couple knots... g

Bowsprits usually have a stay (correct name escapes me at the moment)
down to the water line. In this case you could run the SS strip from
the lower end of the stay down the forefoot, but if you charged into
anything above the water, you'd catch 'sprit stay. Probably the strip
would still help, though.

Rufus

Jeff Morris wrote:

Avoidance strategies might reduce the odds of collision somewhat, but
not enough to
consider the risk eliminated. Radar, for instance, might work in
some conditions, but not
all.

This leaves two approaches: one, which has been discussed, is
preparing to handle the
damage efficiently. I'd be curious what percentage of collision
damages event can be
handled with a collision mat, and how many required abandoning ship.
Clearly, when the
damage is too severe, most vessels will sink like the proverbial
stone, but there are
certain levels of damage where a mat will save the day.

The third approach is to reduce the odds of the vessel sinking, with
positive floatation
and/or collision bulkheads. Multihulls have an advantage, since they
don't have the dead
weight of the keel, and the hulls are shaped to facilitate flotation
chambers. But any
relatively light vessel can be made reasonably unsinkable. One can
make a case that
floatation bags are a better investment than a liferaft.




--
Dan Best - (707) 431-1662, Healdsburg, CA 95448
B-2/75 1977-1979
Tayana 37 #192, "Tricia Jean"

http://rangerbest.home.comcast.net/TriciaJean.JPG



  #27   Report Post  
Doug Dotson
 
Posts: n/a
Default Technique for avoiding collision with floating debris......

Bumber? Most boats aren't designed with the assumption that
the captain runs into thing all the time. When a collision does occur,
it is not always straight on. The few times I have bumped on a
log or other junk, it wasn't head on, but rather hit me along the
sides. If it had been a container, it would have probably pierced
the hull along the forward quarters. It is possible to build a boat
like a tank, but it would be expensive and sail like the Merrimac
or Monitor.

Doug

ps. That would be "Bobstay" or "Robertstay"

"Daniel E. Best" wrote in message
news:wgAvb.271838$Fm2.285478@attbi_s04...
It's frequently called the "Bob Stay" - dunno who bob is/was.

I've always wondered why they didn't mold 6" worth of bumber along the
stem out of that same high density rubber they make auto bumbers out
of. It could be faired into the hull so that it would have a minimal
effect on drag. My understanding is that by distributing the impact
onto perhaps a square foot of the strongest portion of the hull, it
would prevent major damage when striking the object with the stem (which
I assume would be the most likely initial point of contact, as opposed
to a glancing blow along the topsides or some such.
- Dan

Rufus wrote:

For boats w/out a bowsprit, a good thick strip of SS, say 3/16 x 1 (or
1-1/2), running down the stem from below the forestay fitting to the
curve of the forefoot would help reduce damage. Would also help when
indulging in a little "Chicago parking" into concrete docks at a
couple knots... g

Bowsprits usually have a stay (correct name escapes me at the moment)
down to the water line. In this case you could run the SS strip from
the lower end of the stay down the forefoot, but if you charged into
anything above the water, you'd catch 'sprit stay. Probably the strip
would still help, though.

Rufus

Jeff Morris wrote:

Avoidance strategies might reduce the odds of collision somewhat, but
not enough to
consider the risk eliminated. Radar, for instance, might work in
some conditions, but not
all.

This leaves two approaches: one, which has been discussed, is
preparing to handle the
damage efficiently. I'd be curious what percentage of collision
damages event can be
handled with a collision mat, and how many required abandoning ship.
Clearly, when the
damage is too severe, most vessels will sink like the proverbial
stone, but there are
certain levels of damage where a mat will save the day.

The third approach is to reduce the odds of the vessel sinking, with
positive floatation
and/or collision bulkheads. Multihulls have an advantage, since they
don't have the dead
weight of the keel, and the hulls are shaped to facilitate flotation
chambers. But any
relatively light vessel can be made reasonably unsinkable. One can
make a case that
floatation bags are a better investment than a liferaft.




--
Dan Best - (707) 431-1662, Healdsburg, CA 95448
B-2/75 1977-1979
Tayana 37 #192, "Tricia Jean"

http://rangerbest.home.comcast.net/TriciaJean.JPG



  #28   Report Post  
Neil Currey
 
Posts: n/a
Default Technique for avoiding collision with floating debris......


"Jeff Morris" wrote in
The third approach is to reduce the odds of the vessel sinking, with

positive floatation
and/or collision bulkheads. Multihulls have an advantage

This didn't help the racing multi "Bullfrog Sunblock". Sailing from Auckland
New Zealand to Australia it hit a submerged object ,thought to be a shipping
container . It tore out the center hull and sank like a stone.Luckily the
crew was out on deck at the time and survived if the had been in their
bunks who knows.

I have read about "forward looking sonar" , it'd be a hell of a drain on the
batteries to have it on all the time.

Neil C


  #29   Report Post  
Neil Currey
 
Posts: n/a
Default Technique for avoiding collision with floating debris......


"Jeff Morris" wrote in
The third approach is to reduce the odds of the vessel sinking, with

positive floatation
and/or collision bulkheads. Multihulls have an advantage

This didn't help the racing multi "Bullfrog Sunblock". Sailing from Auckland
New Zealand to Australia it hit a submerged object ,thought to be a shipping
container . It tore out the center hull and sank like a stone.Luckily the
crew was out on deck at the time and survived if the had been in their
bunks who knows.

I have read about "forward looking sonar" , it'd be a hell of a drain on the
batteries to have it on all the time.

Neil C


  #30   Report Post  
Jeff Morris
 
Posts: n/a
Default Technique for avoiding collision with floating debris......

How about:
"The Marine Committee of the NZ Insurance Council (http://www.icnz.org.nz) has been
researching issues surrounding the dangers of lost shipping containers in New Zealand
waters, particularly to smaller craft and modern fast passenger ferries. It is known that
a significant number of lost containers in New Zealand waters are not reported. Some
containers remain afloat, often below the surface, long enough to be a real hazard to
shipping."

http://www.veromarine.co.nz/dirvz/ma...otoFeature0007


wrote in message
...
On Fri, 21 Nov 2003 17:23:41 -0800, Josh Assing wrote:

while sailing. Stuff like containers that fell off of freighters will show up on
RADAR. No matter what, there is never any substitute for paying attention. I



not if they're submerged just below the surface....


Please speak in complete thoughts, and maybe even cite real life examples to
support your claim that this could even happen.

Thank you
BB



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