[Rhodes22-list] Combination Of Sharp Turn To Port + Single Handed
Docking
Clarke, Donald R (Don), NPONS
drclarke@att.com
Tue, 14 Jan 2003 09:54:43 -0500
You guys are working way too hard!
I have seen Jim's arrangement and it's cool.
For me I believe in the kiss principle. I run a line from the dock to the outside pier which lives there for the season. When I come in we grab the line with the boat hook and pull ourselves backwards in to the dock. This line is then attached to the boat as a spring line. This allows for our ten minute drill when we are escaping the teenagers looking for money.
Don Clarke
-----Original Message-----
From: Gardner, Douglas L. (LNG-DAY) [mailto:douglas.gardner@lexisnexis.com]
Sent: Tuesday, January 14, 2003 9:44 AM
To: 'The Rhodes 22 mail list'
Subject: RE: [Rhodes22-list] Combination Of Sharp Turn To Port + Single Handed Docking
Slim,
Jim Harrison has this arrangement on his slip, and it works beautifully!
He demonstrated the system to me when he was kind enough to take me for a
sail in September. He does not have a floating dock, though, so I don't
know if the lines could be positioned high enough on David's dock to work
like Jim's. He could keep the forward momentum up so he had plenty of
steerage and just point the boat into the slip. The lines took over from
there guiding the boat to an easy stop exactly where he wanted it. Just tie
off and you're done. The only reason I'm not going to replicate the system
on my floating dock is I'm afraid of chafe ruining my nice new paint job.
I don't know it this is a legitimate concern or not.
Maybe Jim is lurking and will give a better description?
--Doug
s/v Fretnaught
-----Original Message-----
From: Steve Alm [mailto:salm@mn.rr.com]
Sent: Monday, January 13, 2003 5:56 PM
To: rhodes22-list@rhodes22.org
Subject: Re: [Rhodes22-list] Combination Of Sharp Turn To Port + Single
Handed Docking
David,
Some one here on the list (I forgot who) posted this idea: Create a sort of
safety net at your slip for when you're coming in too fast. Fix a permanent
line from the left front corner of your slip to the right side of the slip
about half a boat length back. Then another line just the opposite, from
the right front corner to the left side. This makes the lines cross and
form a "V" several feet out from the middle of your finger peer in your
slip. Then you can come in a little faster (without losing steerage) and
use the "V" to "catch" you and stop you from hitting the dock.
Slim
On 1/13/03 7:44 AM, "Roger Pihlaja" <cen09402@centurytel.net> wrote:
> David,
>
> I pasted your questions in below & added my comments:
>
> "Interestingly, much larger sailboats in the larger slips opposite me =
(the
> ones I back toward as I back out of my slip) seem to have no problem, =
at
> least when I seen them come and go on normal days. One skipper with =
two
> small sons repeatedly brings his 35-foot sailboat to a dead stop =
centered
in
> his slip with no lines whatsoever. The only differences I can see =
are:"
>
> "(i)they are headed towards a larger opening"
>
> The degree of difficulty (DoD) of entering a given slip can be thought =
of
in
> terms of the ratio of the
> slip width/max boat beam. If your slip is only 10' wide & your R-22 =
has
an
> 8' beam; then, your
> DoD = 10/8 = 1.25 That 35' LOA sailboat probably has a 12' beam. =
If his
> slip is 50% wider than yours,
> or 15'; then your friend faces a challenge of: DoD = 15/12 = 1.25 =
or
> proportionately the same as you. On the Great Lakes, where boats tend =
to
be
> larger, slips in recreational marinas are rarely more than 20' wide. =
I
know
> this max slip dimension from sailing on my friend's 42' sailing =
catamaran,
> which has a 23' beam - we anchor out a lot. But, on a small inland =
lake
> like yours, a 15' wide slip wouldn't surprise me, especially if the =
rest
of
> the marina is laid out small & cramped as per your description.
>
> "(ii) they are turning to starboard, if that makes any difference--is =
that
> what people talk about when they refer
> to a right-hand prop?"
>
> Prop side thrust or "prop walk" is caused because the prop is =
operating in
> water that is less dense on the top of the prop vs. the bottom of the =
prop
> because of the weight of the water above the prop. A right handed prop =
has
> the blades arranged such that; when viewed from astern, the prop =
rotates
> clockwise when generating forward thrust. The density difference of =
the
> water across the vertical diameter of the prop causes a side thrust to =
be
> created. In the case of a right handed prop, this side thrust is =
directed
> to starboard. A side thrust to starboard at the stern of the boat =
causes
> the stern of the boat to be pushed to starboard. Pushing the stern to
> starboard causes the boat to rotate about its CR in a counterclockwise
> direction - in other words it turns to port. Large diameter, slow =
turning
> props tend to produce proportionately more side thrust vs. small =
diameter,
> fast turning props. For a left handed prop, all of the above =
arguments
are
> reversed. In reverse gear, the right handed prop turns =
counterclockwise,
> the stern of the boat is pushed to port, & the boat tends to turn to
> starboard.
>
> "(iii) their prop is inboard and at the centerline of their boat, =
giving
> better steering control."
>
> On an R-22, having the prop mounted to port of the boat's centerline
> generates a torque about the CR in forward gear that tends to rotate =
the
> boat in a clockwise direction. In other words, in forward gear, the =
port
> offset location of the prop tends to make the boat turn to starboard. =
In
> reverse gear, the offset thrust tends to make the boat turn to port. =
Note
> that this has nothing to do with whether the prop is right handed or =
left
> handed. This phenomenon is simply a side-effect of mounting the prop =
off
> the boat's centerline.
>
> So why is it so hard to turn sharply to port with a strong wind from
astern?
> Well, the hull presents much less surface area to the wind when it is
> oriented stern-on vs. side-on to the wind. So, energy is required to =
turn
> the hull from stern to the wind around to side to the wind. Energy is
also
> required to hold the hull in the side to the wind orientation as the =
wind
> tends to rotate the hull back to the stern to the wind orientation. =
Where
> does this energy come from? There are two potential sources, the =
kinetic
> energy of the boat itself & from the motor. In a crowded marina
situation,
> the boat is going to be moving slowly. So, you don't have very much
kinetic
> energy to start off with. But, suppose you start the turn anyway? As =
the
> boat turns, the viscous drag of the hull in the water + the windage =
work
> together to use up your kinetic energy. You will likely end up turned
> side-to-the-wind, but stopped dead in the water. When the water stops
> flowing across the rudder blade, it stops generating any steering =
forces.
> The wind keeps blowing. The boat is blown out of control back =
downwind &
> tends to rotate back to the stern-to-the-wind orientation! So far, =
these
> effects are pretty much the same for a port or a starboard turn. OK,
> suppose we add some power from the port offset mounted prop? In =
forward
> gear, even with the motor turned full lock to help the port turn, a
> substantial fraction of the thrust is acting against the turn. This =
is
the
> difference between a port turn & a starboard turn. You can't use too =
much
> throttle because a substantial fraction of the thrust is also pushing =
the
> boat forward. Using too much throttle will result in the boat =
finishing
the
> turn & entering the slip going much too fast. Now, when you put the
engine
> into reverse & apply full throttle to stop, the prop side thrust tries =
to
> turn you back in the direction you came from. Arggg! Overall, this
> technique simply has everything working against it. It's a delicate
> balancing act that requires good eye/hand coordination & a good sense =
of
> speed & distance all performed in real time under stress with dire
> consequences for failure!
>
> But, if we put the engine into reverse, turn it to full lock in the
opposite
> direction, & now apply full throttle; everything is different. With
reverse
> thrust, the port offset engine location is tending to assist a port =
turn.
> Full reverse throttle will tend to slow the boat down, not speed it =
up.
So,
> you get up a good velocity before starting the turn, use the reverse
engine
> thrust to spin you around + burn off your speed. With a little =
practice,
> you will find you can pull a sharp 90 deg turn to port, finishing the =
turn
> with the bow at the entrance to your slip, with the boat moving slowly
> forward at just the right speed for docking. Then, you shift into
neutral,
> slip your single dock line over a piling or cleat, stop parallel to =
the
> dock, quickly attach your bow line, & then your stern line. Then, =
briefly
> stop to acknowledge the applause from your fellow boaters! I know =
this
> technique sounds radical, but I guarantee it really really works.
>
> Roger Pihlaja
> S/V Dynamic Equilibrium
>
> ----- Original Message -----
> From: "David Keyes" <dkeyes@houston.rr.com>
> To: "The Rhodes 22 mail list" <rhodes22-list@rhodes22.org>
> Sent: Sunday, January 12, 2003 12:35 PM
> Subject: Re: [Rhodes22-list] Combination Of Sharp Turn To Port +
> SingleHandedDocking
>
>
>> Roger, I will try your single dock line. But the challenge with a =
brisk
>> wind astern has been even to get that far (to where one is entering =
the
> slip
>> between the finger piers), where you could get to the dock line. I =
have
> to
>> think about coming in close on my port side to the sterns of the =
upwind,
>> docked boats just before my slip and fetching the dock line for a =
pivot
> into
>> the dock, but this couldn't work single-handed due to the protruding
>> outboard motors of the other boats. I have been coming down the =
"alley"
>> between the adjacent piers with my boat about 2/3 to 3/4 of the way
> towards
>> the opposite pier to allow for turning room but without my stern =
getting
> too
>> close the the sterns of the boats to starboard as I make my turn to =
port.
>>
>> As to your question: Of course the wind is not always that strong. =
I
> have
>> since found out, talking to the marina personnel and some other boat
> owners,
>> that (virtually) no one goes out on days where there is a strong =
onshore
>> wind (northerly wind--we are on a southern shore), which would be =
rare in
>> the summer but is common in the winter. They don't go out because of =
the
>> same problem of returning to docks. But I am going to ask a few of =
the
>> owners who seem to use their boats frequently, year around.
>>
>> Even on the November day of my docking accident when mine may have =
been
> the
>> only boat out, I and my crew of two thought we were successfully =
turning
>> into the slip without incident after a great sail when at the last
instant
> I
>> decided that the wind had caught the bow so that it was going to be
pushed
>> too hard into the entering edge of the starboard finger pier. I hit
> reverse
>> on the engine to soften the blow (and one crew member jumped onto the
pier
>> at that point) to try to push the boat off, when my motor jammed in
> reverse
>> and we went rocketing back into the boats in their slips behind me. =
(It
> was
>> when I forced the gear shift into forward just missing a collision =
with
>> those boats but permanently jamming the gear into forward).
>>
>> Interestingly, much larger sailboats in the larger slips opposite me
(the
>> ones I back toward as I back out of my slip) seem to have no problem, =
at
>> least when I seen them come and go on normal days. One skipper with =
two
>> small sons repeatedly brings his 35-foot sailboat to a dead stop =
centered
> in
>> his slip with no lines whatsoever. The only differences I can see =
are
(i)
>> they are headed towards a larger opening, (ii) they are turning to
> starboard
>> if that makes any difference--is that what people talk about when =
they
> refer
>> to a right-hand prop?, and (iii) their prop is inboard and at the =
center
>> line of their boat, giving better steering control.
>>
>> Lastly, even on relatively calm days, the approach to the slip =
requires
>> skill, paying complete attention, good anticipation and decisions and
>> sometimes a little luck. Many years ago, I had boats at marinas in =
lakes
>> and bays where this was not the case, within the limits of prudent
>> seamanship. For five years at one lake, I just sailed to the dock =
with
no
>> motor at all (boats of 17 and 19 feet). In Biscayne Bay in Miami, I
> docked
>> regularly a 34-foot motor sailer in many kinds of weather and never =
any
>> problem. However, in the present case, for one thing, I usually have =
to
>> start my hard turn to port as if I were going to head into the =
(already
>> occupied) third slip out from me. If one were driving a car doing =
this
on
>> dry land, one would crash into the motor at the back of that boat. I
have
>> to "slide" out to starboard during the turn to actually come in,
> hopefully,
>> right in the middle of my slip without touching anything. =
Surprisingly,
>> this works at least half the time, and over the past 1-1/2 years =
until
>> November, the rest of the time involved a bump into a fender or the =
like,
> so
>> no big deal--at worst a rubbing of the gel coat alongside the white
rubber
>> strip at the edge of the finger pier, or against the small turning =
wheel
> at
>> the entrance to the port finger pier. But there should be a way to =
make
>> this virtually 100% successful in all but emergency weather =
conditions
and
>> where you could even explain to a guest skipper what he or she needs =
to
do
>> as the best technique for this particular slip. My success rate had =
gone
> up
>> significantly after the first few months of owning the boat when I
started
>> the practice of, if needed, momentarily engaging the engine in =
forward
>> during the turn, with the motor linked to the tiller. Then, if I =
weren't
>> going to complete the turn in time (i.e., coming in too far too
> starboard),
>> I would change the tiller/linked motor steering direction bringing =
the
>> tiller hard to port and momentarily hitting reverse to straighten the
boat
>> out before proceeding (hopefully) straight into the slip. This =
appears
to
>> have been hard on the engine, as you said in an earlier email.
>>
>> Roger, I really like your earlier suggestions, which I quote below:
>>
>> "You might consider finding a different slip for next season. For
example,
> a
>>
>> slip right across from you would be better. A tight turn to starboard =
in
>>
>> this situation is much easier than to port.
>>
>> "If it were my boat & I were being more cautious, I think I would =
pull up
> to
>>
>> the end of the finger pier, port side to the pier. I would either put =
out
>>
>> fenders on the port side amidships or mount a suitable bumper on the
> corner
>>
>> of my pier. I would loosely tie off amidships & use a bow line to =
warp
the
>>
>> bow around into the slip. No muss - no fuss."
>>
>> There is not alot of room to do this at my slip, but it should be
> feasible.
>> The finger pier at the port is only one foot wide, and their is a =
long
> boat
>> with a motor protruding to port. Likewise there is a boat and =
protruding
>> motor on the starboard side of my slip (mine being the last full one =
with
> a
>> finger pier on both sides to make an enclosure), and which of course =
one
>> would not want to "warp around" outside the edge of the slip and into
that
>> motor. The slip is 10 feet side. So what you say should work with a
>> practiced technique, and I am going to try it. Using your single =
dock
> line
>> idea in your article quoted below, this could also be the line that =
I
> fetch
>> at the end of the port finger pier.
>>
>>
>> David Keyes
>>
>>
>>
>> ----- Original Message -----
>> From: "Roger Pihlaja" <cen09402@centurytel.net>
>> To: "The Rhodes 22 mail list" <rhodes22-list@rhodes22.org>
>> Sent: Sunday, January 12, 2003 5:53 AM
>> Subject: [Rhodes22-list] Combination Of Sharp Turn To Port + Single
>> HandedDocking
>>
>>
>>> Thank you Steve & Mark! This was the article on single handed =
docking I
>> was
>>> refering to.
>>>
>>> So, David, what do you think? Wouldn't executing a sharp 90 deg =
turn to
>>> port & throwing a single dock line over a piling or cleat on the end =
of
>> your
>>> finger pier be more graceful & less taxing on your equipment than =
what
> you
>>> do now?
>>>
>>> By the way, if your marina is so tight & the wind blows like you =
say,
> how
>> do
>>> the boats around you get into their slips?
>>>
>>> Roger Pihlaja
>>> S/V Dynamic Equilibrium
>>>
>>> ----- Original Message -----
>>> From: "Steve Alm" <salm@mn.rr.com>
>>> To: <rhodes22-list@rhodes22.org>
>>> Sent: Friday, January 10, 2003 5:41 PM
>>> Subject: Re: [Rhodes22-list] Single Handed Docking Article
>>>
>>>
>>>> Here it is:
>>>>
>>>> All boats have a point along both sides, usually just aft of
> amidships,
>>>> wherein a single dock line will cause the boat to stop parallel to =
a
>> dock.
>>>> To find this point, pick a place along the side. It's helpful to =
use
>> the
>>>> sliding cars on the genoa tracks for this purpose. Attach a =
mooring
>> line
>>> to
>>>> this point & pull on it from behind. If the bow pulls towards you
>> faster
>>>> than the stern, then slide the attachment point aft. If the stern =
is
>>>> favored, then move the attachment point forward. When the boat =
crabs
>>>> sideways towards you, then you have found the approximate sweet =
spot.
>> The
>>>> actual sweet spot will shift slightly when the boat has forward
>> momentum.
>>>> However, this approximate location will be sufficiently close to =
allow
>> you
>>>> to go out & try to pull up to a dock with a single line. Try to =
stop
>> the
>>>> boat with a single mooring line using your approximate sweet spot. =
If
>> the
>>>> bow or stern tend to crab towards the dock faster, then adjust the
>>> position
>>>> of the line fore or aft as before & try again. When you have found
> the
>>>> correct location, you should at least mark it. You may even wish =
to
>>> install
>>>> permanent mooring cleats there port & starboard.
>>>>
>>>> With a single mooring line, simply motor up to the dock, slip your
> loop
>>> over
>>>> the piling near the end of the dock, & shift into neutral. The
> mooring
>>> line
>>>> attached to the sweet spot will snub the boat's forward momentum & =
the
>>> boat
>>>> will almost magically "crab" sideways up against the dock. This
>> sideways
>>>> crabbing involves a tremendous amount of drag, which uses up the
> boat's
>>>> forward momentum in a matter of inches, thus making it almost
> impossible
>>> to
>>>> hit the dock. The boat will stop at a convenient distance away =
from
> the
>>>> dock for you to go around attaching your bow & stern lines at your
>>> leisure.
>>>> Try this technique. I guarantee it will make you look like a boat
>>> handling
>>>> genius!
>>>>
>>>> Roger Pihlaja
>>>> S/V Dynamic Equilibrium
>>>>
>>>> On 1/10/03 12:50 PM, "Roger Pihlaja" <cen09402@centurytel.net> =
wrote:
>>>>
>>>>> Hey Everyone,
>>>>>
>>>>> Did anyone happen to save a copy of an article I wrote several
> months
>>> ago re a
>>>>> foolproof single line docking procedure? I can't find it in the
>> SailNet
>>>>> archives or on the FAQ page & I don't know how to search the new
>>> archives.
>>>>> I'd really rather not retype the whole thing if someone has a copy
>> they
>>> could
>>>>> repost.
>>>>>
>>>>> I'd like to forward it along to David Keyes. The combination of =
the
>>> technique
>>>>> for making a sharp turn to port which I described in my previous
> post
>>> along
>>>>> with this single line docking technique might work very well in =
his
>>> situation.
>>>>>
>>>>> Roger Pihlaja
>>>>> S/V Dynamic Equilibrium
>>>>> _________________________________________________
>>>>> Use Rhodes22-list@rhodes22.org, Help? www.rhodes22.org/list
>>>>
>>>> _________________________________________________
>>>> Use Rhodes22-list@rhodes22.org, Help? www.rhodes22.org/list
>>>>
>>>
>>> _________________________________________________
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>>
>> _________________________________________________
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>>
>
> _________________________________________________
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