wrote in message
...
On Mon, 28 Jul 2008 08:28:01 -0400, "Roger Long"
wrote:

wrote

Lifelines are intended for rather severe loads, such as a 200 pound crew
being
thrown against it. If your (editorial "your") lifelines can't be trusted
to
support a few 5-10 pound fenders, it's time for some serious upgrades.


That doesn't sound like a statement from someone whose been around much,
although I know you have.

One of the jackasses roars through the no wake zone, the boat rolls down
and
hooks the fender under either the guard or the protruding edge of the dock
planking and then rolls up as it's pushed against the dock. Strain is now
the lesser of:

The breaking strength of the fender line.

The righting moment of the boat with some inertia factor thrown in.

The force necessary to shread or collapse the fender and pull it out.

Either of these is likely to be well in excess of the strain you would
like
to routinely put on a safety item your life might depend on some day.
I've
seen it happen.

Just because lifelines don't fail when subjected to common abuse doesn't
mean bedding and laminates are not being compromised at the bases in ways
that could weaken them down the road. Stanchions are a difficult
engineering problem on all except metal boats where they are welded to the
structure. Treat them with the respect you would any important safety
equipment.

The strongest direction for life lines is downward force, which is
what happens of a fender gets caught under a dock. The weakest is the
sideways force of someone being thrown against them. They are also
somewhat sacrificial in nature. In a contest between my fenders and
the righting moment forces of the boat, I'm pretty confident that the
fender whips would part long before the lifelines got anywhere near
the failure point. For that matter, the finger of my floating dock
could probably be lifted until either the fender whip failed or the
fender came free, without breaking the lifelines.

Where do you get this? A fender, caught under a dock will tear the lifeline
right off the boat. In fact, it'll collapse the entire side. I've seen this
happen. Why would you want to sacrifice $100s worth of lifeline instead of
tying the fender line to a proper spot... In addition, the daily stress of
the lifelines being moved back and forth with the fender that is rubbing
will degrade the lines and the "whip" will certainly fail sooner rather than
later.

For that matter, a couple of weeks ago, my wife lost her grip on a
fender (clipped to the lifeline) as she was putting it over the side.
The plastic clip holding the fender gave it's life and we had to go
back and retrieve the fender. I don't think the lifeline even noticed.

http://www.iboats.com/Fender_Tender_II/dm/cart_id.069729997--category_id.238302--list_time.1217250756--session_id.974456088--view_id.38397

Once time does not make for constant stress...


--
"j" ganz @@
www.sailnow.com