rode rider idea

[windship]

Jim,
If your having one of those ''wild night''s'' on anchor watch and that rode is taught(spelling), any effect from a sentinal is gone. This means that the anchor would have held anyway.
If you don''t mind the hassle, use it but there is no alternative to scope 0r an anchor designed for use with shorter scope.

Dennis

[GordMay]

You don’t appear to understand the simple physics underlying anchor & rode dynamics.
It takes a certain force to elevate the Sentinel weight and rode. This is force that is NOT acting upon the anchor, hence the sentinel is still assisting.
You do lose elasticity once the rode is straightened out (sentinel elevated & rode taut).
Don’t expect even a sizable sentinel to make up for inadequate scope.
Respectfully,
Gord

[windship]

Gord,
It is the people that receive a false sence of security from using this ridiculas outdated method, that don''t understand.
It seems to me that anybody needing to practice this method is doing somthing wrong. Ie more chain or heavier chain or both or more scope or an anchor that works well on short scope.
My advise comes from decades of anchoring with a CQR, danforth, Bruce and mooring instalation, repair and consultation....I understand perfectly.
Respectfully,

Dennis

[jbanta]

In the event you come across a crowed anchorage with weather coming in on you and your ONLY salvation is anchoring short scoped and a using one of the these ridiculas outdated methods that would give you extra holding power. You wouldn''t do it?

[windship]

jbanta,
No, I would not.
I''ve been in that exact scenerio.
I have a bruce 33(boat disp. 12,000lbs)that I now use religiously because of it''s performance. In one of my boat''s saloon sole compartment''s There is 60'' of 3/8 chain that I use for just such an occation. This chain is attached to the Bruce and lowered to 3:1 scope.
End of problem.
I''ve only had to use this set-up once because the Bruce is normaly attached to 20'' of 3/8 chain that has held fine in all my other anchoring scenario''s.
It IS a antiquated method that give''s boater''s a false sence of security while the anchor would have probably held anyway.
Would anybody like to offer their ground takle set-up so that we might debet this further? What are you using for anchor''s, rode and chain. Boat length, displacement, condition''s etc.
Respecfully,

Dennis

[GordMay]

Dennis:
I agree with your assertions that “... more chain or heavier chain or both or more scope ...” remain our first line anchoring strategy.
I don’t understand your vehement objections to the ADDITIONAL security a Sentinel can offer.
With all due respect, you’ve said nothing (including your CV) that indicates you understand the physics/mechanics of how anchors & rodes work, and behave under dynamic conditions.

FWIW:
“Southbound” (C&C 29'' @ 6800# dry) carries 4 anchors:

Fortress FX23 (clipped on bow rail) c/w 10'' of 3/8" High Test Chain + 200'' of 5/8" Three-Strand Nylon. My all-round first choice, weighs only 15 Lbs, /w incredible holding power.

35# Delta (on bow roller) c/w 50'' of 3/8" H.T. chain & 200'' 3-Strand 5/8" Nylon.

22# Bruce (in anchor locker) c/w 30'' of H.T. chain & 150'' 1/2" Double Braid Nylon. Worked well in L. Superior, but not so well in Bahamas.
Replaced /w second
FX23 rigged as above (saved Bruce, but never used again).

Three "extra" storm rodes @ 150'' each - 1/each 1/2", 5/8", & 3/4" dia. (bend on as required).

Two “extra” chains - (1) 1/4" P.C. @ 50'' + (1) 5/16" H.T. @ 25''L.

In heavy weather, I always deploy 15 Lb "Sentinal" (Kedge, or Kellet) weights, suspended a few feet above bottom. (carry 3)

I seldom anchor in more than 12'' water depth in Lk. Superior, or 10 - 20'' in Bahamas.

Respectfully,
Gord May

[mgiguere]

The technique I use (albeit rarely) is my 22 lb bruce on a swivel with a Danforth set 90 degrees from the Bruce. I''ve never tried the sentinel approach, but my system works great. My boat is a 37ft sloop that displaces 14,500 lbs.

[windship]

Gord,
I''ve explaned, in detail, my disbelief of the kellet''s effects on short scope and why. Sorry you don''t get it. Someday, while your using your kellet, try removing it and see if there''s any change.
Also, that''s an impressive ground tackle assortment. I think you need a bigger boat.

Dennis

[GordMay]

Dennis (Windship) and others:

Let me begin by apologizing to you. I believe that gentlemen can disagree gracefully; but the tone of my recent postings may have crossed over the line of proper decorum.
By way of explanation (not excuse), I was hoping to provoke you to explain your position in more detail. I value the lively interaction the Sailnet Forum provides, and your contributions to the debate. Please don’t let my poor manners reflect badly on the concept of “debate”, and the exchange of differing points of view.

Yes, “Southbound” is abundantly (over-equipped?) equipped with ground tackle. I’ve never recommended that anyone must emulate my conservative approach to ground tackle, but it gave me peace of mind, and never let me down. I’m an admitted “nut” on anchoring.

Although I have done a lot of reading on the subject of anchors and anchoring, I’m not totally without practical experience.
I’ve spent over 4,000 nights aboard several boats, nearly half of them at anchor.
I’ve also spent at least 20 hours (accumulated time) in the water, observing the anchor & rode dynamics, under a variety of conditions (mostly more ‘boisterous’). This was dedicated scrutiny, to which I’d add countless casual observations made when “diving the anchor”.

The ABYC “Loading Table I” (which I referred to) actually specifies more than I quoted:
30 LOA, 9'' Beam, Sail, and footnoted:
1. When using this table with the LOA or Beam, use whichever gives the highest loading, assuming freedom to oscillate is permitted and moderate shelter from seas proportionate to hull size.
2. Boats with canvass and large superstructure, use the load one category higher than that determined by using the powerboat column.
3. These values include the effect of wind, current, and wave action.
30'' LOA (Sail) @ 9'' Beam - 700# Working, 1,400# Storm, & 2,100 Mooring
35'' LOA (Sail) @ 10'' Beam 900# Working, 1,800# Storm, 2,700# Mooring

Many authorities consider these tables to be very “conservative”.

Sone References that might interest you:

“Tuning an Anchor Rode” ~ by Alain Fraysee
http://alain.fraysse.free.fr/sail/rode/rode_b.htm
In particular: “Dynamic Behavior (2) - Heterogeneous Rode”
http://alain.fraysse.free.fr/sail/rode/dynam/dynam.htm

“Anchor Catenary Details” ~ by John Holtrop
http://www.johnsboatstuff.com/Articles/anchor.htm

“Anchor Design Theory” ~ From the Dutch firm Vryhof Ankers
http://www.vryhof.com/PDF/AM2000B.PDF

“ Anchor rode” ~ by Alain Hylas (Inbventor of the ‘Spade’ anchor)
http://www.bluemoment.com/anchorrodes.html

“Rope to Chain Splice Test” ~ by Chuck Hawley (West Marine)
http://www.ussailing.org/safety/Studies/1994ropechainsplice.htm

“Principles and Performance of Anchors” ~ from the manufacturers of the ‘Flook’ anchor
http://www.dulhunty.com/dmp1.htm#top

“Anchoring” ~ from BoatUS ‘BoaTECH’ Guides (includes ABYC Table I)
http://www.boatus.com/boattech/anchorin.htm

“Anchoring” ~ from the Banjer 37 Motorsailer Club
http://banjer37msclub.tripod.com/workshop.htm

Best regards,
Gord May
Gord@BoatPro.zzn.com

[GordMay]

It just occurred to me that I’ve also used a Sentinel when docked.
We summered in the Ft. Lauderdale canals, where we had short (6-8'') finger docks projecting out from a face wall (seawall, or bulkhead).
I’d use a Sentinel weight (about 20#) centered on the forward bow line, opposite the finger. This kept the boat away from the finger under normal circumstances, but allowed us to pull her over for easy boarding.
The sentinel exerted enough force that Maggie (at about 105# soaking wet) had to put her back into it.
FWIW,
Gord