I have an unusual (I think) docking situation. Because of the very awkward
inside corner slot I'm in, and because my the forward pilings are beyond the
length of my boat, I find that all 4 docking lines must be at a precise
length to avoid damage at multiple points. If my stern lines are too long,
my bow may hit my neighbor's boats (my port side neighbor is parallel to me,
starboard is perpendicular). If my bow lines are too long, my outboard
motor will hit the dock. The docks do not float; so if any of the lines are
too short, I risk damaging either my boat or the dock in exceptional tides.
After hours of watching and adjusting, I have the lines set to the right
lengths for average tidal changes (i.e., my boat is horizontally centered by
the four lines, with just enough slack to allow for normal tides). Quite
literally, these lines cannot be changed more than a few inches from current
lengths.
I am, however, concerned about those exceptional tides. I am wondering if
anyone has seen/heard of a spring-device that could be installed in-line, so
that the working length of a line does not change unless a certain force is
brought to bear upon it (i.e., the wind won't stretch the spring but the
weight of the boat will). In effect, this would give me a fixed line length
for normal situations, but the springs would stretch before ripping out
cleats., etc.
I don't know if anyone has the answer, but I know I'm sure to get a few
bruises/laughs!
Thanks in advance.
Scout

Scout, the problem would be that as soon as the exceptional tide was over (probably while you are not at the dock) then your
boat is sitting there with too long lines. What about a davit arrangement from the dock? (I'm having a hard time imagining what
you're describing...sounds like a parking lot at a high school....)

--
katysails
s/v Chanteuse
Kirie Elite 32
http://katysails.tripod.com

"Women and cats will do as they please, and men and dogs should relax
and get used to the idea." - Robert A. Heinlein

I'm thinking the spring would relax again when the water rises to normal
range, thereby leaving the lines at the 'normal' length.
You're right though, it's like parking in Philadelphia.
Scout


"katysails" wrote
Scout, the problem would be that as soon as the exceptional tide was over
(probably while you are not at the dock) then your
boat is sitting there with too long lines.

Scout I'm not certain from the description you provided but..... would dock
whips be of any use?

CM

"Scout" wrote in message
...
| I have an unusual (I think) docking situation. Because of the very
awkward

thanks CM, whips are a possibility, with a some customizing.
Scout


"Capt. Mooron" wrote
Scout I'm not certain from the description you provided but..... would
dock
whips be of any use?

Scout,

Have you tried long spring lines and crossed. Stern to bow, with docking
line bow and stern?

Ole Thom

"Scout" wrote in message
...

I don't know if anyone has the answer, but I know I'm sure to get a few
bruises/laughs!
Thanks in advance.

Have you tried using spring lines, either instead of, or in conjunction with
your bow and stern lines?


What is the normal spring tide? What are the exceptional tides like?

I've seen three different devices.

Two are fairly simple, but they only give a couple of inches of expansion.
They are really intended for protection against sudden shock loadings.

One uses a length of thick rubber with an eye in both ends and the mooring
line is wrapped around it.
The other is a DIY version. You open up the strands in a three strand
mooring line, and feed in some bungee cord for about 18 inches. This
results in a "fat" section which can stretch by compressing the bungee cord.


The third device might be more suitable. It is a heavy duty spring that
compresses as the line gets tighter. This might provide 8-10" of expansion.




Regards


Donal
--

I know graphics attachments are not appreciated, so here is my best shot at
communicating the arrangement with an acceptable graphic. My boat is "me".
I tie off at points P2, P3, x1, and x2. At this point the lines are not
crossed. Pilings P2 and P3 would keep a longer boat in line, but a bigger
boat would probably not be able to squeeze into the slot. So they gave it
to me. I was happy to get it because it seems someone has to die to get a
slip here.
I keep P2 and P3 just short enough so my outboard does not bump the dock, or
worse, get stuck under it at low tide. The x2 line keeps me from angling
and hitting boat A, while x1 keeps me from hitting the floating work
platform 'C'
You folks gave me a few new ideas to try, thanks.
Donal, my NOAA chart says this about the tide: "with strong winds of long
duration, the change in depth may amount to a maximum of 3 feet above or
below the normal high or low water respectively."
Also Donal, the third device you mentioned sounds like what I had in mind.
Now that I know they exist, I will start looking and asking in marine shops.
Thanks again to all of you for your help.
Scout

P4 X
A X
A B B B B B B B B B B B B X
A X
P1 A P2 P3 X
A X
A me C C C C C C C C C X
A me C C C C C C C C C X
A me C C C C C C C C C X
A me C C C C C C C C C X
A me X
X A X me X X X X X X X
X A X me X X
X A X me X Gazebo X
X A X me X X
X X x1 X x2 X X X X X X

whe X = Stationary Dock
A = 38' Fishing Boat
B = 25' Motorboat
C = Floating Work Platform
me = my 21' sailboat (including outboard motor)
P* = Piling with tie-up cleat
x1, x2 = tie up cleats

On Sun, 20 Jul 2003 17:31:17 -0400, "Scout" wrote:

I know graphics attachments are not appreciated, so here is my best shot at
communicating the arrangement with an acceptable graphic. My boat is "me".
I tie off at points P2, P3, x1, and x2. At this point the lines are not
crossed.

If you cross your lines their will be less change in vertical angle as the tide
rises and falls, so there will be less change in horizontal distance.

Are you using three strand twisted nylon for the dock lines?

S/V Cat's Meow
http://www.catsmeow.org

"Scout" wrote in message
...
thanks Gerard,
the front lines are doable, but the back lines seem to get hung up in the
motor when I cross them.
Yes to the 3 strand twisted nylon.
Scout

I wouldn't use P2 and P3 to stop the outboard hitting the dock.


I am assuming that the dock is at the bottom of your picture, that you have
reversed into your slip, and that your outboard protrudes over the stern.

I would run lines from P2 and P3 to the stern of the boat. These lines
would prevent the boat backing into the dock. I would also run lines from
x1 and x2 to the bow of the boat. These lines will prevent the boat from
moving forward. These four lines should be made off very tight, as they
will stretch.

The bow and stern lines are only to prevent lateral movement, and only need
to be tight enough to stop the boat moving too far sideways. My boat always
ends up with tight springs, and drooping bow and stern lines.



Regards


Donal
--