|Topic Review (Newest First)|
|07-18-2007 10:28 PM|
|camaraderie||Jef...sounds similar to what I do. I like the fact that you let the anchor set itself. I have found this works best too...particularly with CQR's...and as I recall I learned this lesson one long night in eel grass! (G)|
|07-18-2007 09:49 PM|
|sailingdog||Thanks for the clarification... sounds like a good system for your boat...|
|07-18-2007 09:09 PM|
The windlass is NOT taking the load in my approach. Perhaps you don't understand that the load of the line is on a "bow" cleat which is 3.5' ± aft and slightly to the side of the vertical gypsy of the windlass. The line does exert some lateral force on the drum, but the cleat is doing all the work. The windlass drum is functioning the way a deck block might which changes the angle of the line 20 or 30° such as my halyard which then passes aft to a line stopper. The line stopper is taking the load, much the way the cleat does for my anchor.
In fact, the anchor line load is usually so little that I can "lift" the line off the drum or pull it away from the drum with not much effort. This is much less force than using the drum to pull the 1200# it is rated for.
The only use for chafe gear is when the bow is shearing too much and the line might just jump out of the bow roller and chafe against the ss cheeeks of the bow roller assembly. This is rare and to combat that I set a riding sail which will weathercock the boat and mitigate yaw. And finally the roller housing can accommodate a second roller which I can insert, using a removable SS pin slightly aft and above the bow roller. This "forces" or holds the snubber line down into the main stepped bow roller so it doesn't ride up to chafe against the cheeks.
However in most cases the snubber line rides on the bow roller with no chafe whatsoever.
The ultimate "no chafe" approach is to connect the bitter end of the mooring snubber to my bow eye. This gives me another 40' of 1" nylon rode added to the max 200' of chain and lowers the attachment point 2' increasing the scope ratio. No place to chafe. When the blow is over I can pull in some chain and take the load off the line and move or remove it.
Again, using a bridle mean using fair leads and in my case that means through the metal toe rail and this is a chafe point. This is the place where boats on moorings chafe through leaving the loop on the cleat!
Chafe is the enemy of the sailor.
|07-18-2007 08:08 PM|
the only major suggestion I'd make is switching from tygon tubing to dyneema woven chafe protector. One of the major sources of nylon lines failing is due to internal friction and heat buildup... tygon tubing prevents the seawater or rain from getting to the nylon rope and lubricating/cooling it... so may increase your chances of having the line fail. This isn't completely necessary, since, in your case, the nylon snubber is just for comfort and to reduce shock loading on the boat rather than the actual connection to the anchor. The dyneema woven chafe sleeves allow the water to penetrate and lubricate the line and prevent much of the friction and heat.
I would also think that it would still be wiser to tie the snubber off to a properly mounted mooring bitt, rather than take the load on the windlass. Most windlasses say in their installation and use guides that they are not designed to take the shock loading of the anchor rode, and that the rode should be made fast to the boat elsewhere.
|07-18-2007 07:58 PM|
My experience with anchoring... and the technique I have developed has come from living aboard for 4 yrs and cruising on my boat in the Caribbean, and in New England for 21.
My snubbing line is actually 1" nylon braid and I do have a 30" length of tygon plastic tubing which I can slide to mitigate chafe. But usually there is no chafing points.
My windlass is a Maxwell 1100c vertical (about 1,200# pull) and the snubber line is led around it and the angle is hardly enough to stress or bend the windlass. I would estimate the angle is something like 210°. I don't have to lead it this way, but when I do retrieve the tackle with the snubber using the windlass it is easier.
Of course the snubber line, the rubber compensator, the chain all have to be sized for the vessel and it also depends on the number of wraps you take around the rubber.
My vessel displacement is 16,000 and I use a compensator for 24mm line and boats up to 20 meters. The EDPM rubber is very stout and unaffected by UV.
Other yachts use a rather short length of line which may absorb some shock, but nothing like the rubber compensator which I can see stretch at times to perhaps 1.5x its length.
If it does "snap" the thick nylon line is still there as shock absorber and the jerk would not be very much, certainly not enough to do damage of part the chain I would think. I have never been there so I don't know.
I set my anchor from the bow, not from the cockpit backing down with the motor. I let the wind push the boat back, lay out the chain and then the flukes dig in. When they do the CL of the boat will align with the chain and if the wind is strong enough it will lift the catanary.
I then set the mooring snubber with the captive compensator and let out about her 15'+ foot of chain. The chain aft of the chain hook drops down in the water and the line takes the load. If the wind is strong enough the compensator will untwist a bit indicating that there is considerable tension in the rode. The catanary and the rubber are now absorbing the shock. I experience not jolts with this system. This system can easily hand tension from 50 knots according to the component specs.
If I want to use MORE nylon line I can, by slipping the line on the cleat up to 40'. If the windlass has problems or the anchor is stuck, the snubber line has a float attached at the bitter end so I can drop/ release the chain and it will have a float on it for retrieval later.
I often put a float on the anchor as well.
In more than 16 yrs using this very system I have dragged but once or twice and I think the anchor was fouled in eel grass. The CQR doesn't like eel grass.
My "permanent" mooring system uses a large bow eye (5/8" Ø ss) which is attached through a very stout SS stem fitting on the boat. My mooring painter is not a loop, but a huge Wichard 4,000# rated ss snap hook carabine. There is no possibility for chafe. I have a typical loose 1" - 3 strand mooring painter with a loop on the bow cleat as a back up. This painter takes no tension under normal conditions and serves as a "safety" line back up.
And suggestions or comments?
|07-17-2007 12:25 PM|
Thanks for the diagram and info on the snubber. That is exactly what I've been looking for. And to think it came from a fellow "True Blue" That's the name of our boat also!
|07-14-2007 06:58 PM|
|Giulietta||I have a very good instructional paper on how not to use a danforth...any one interested???|
|07-14-2007 05:20 PM|
When you do set your Anchor. Be sure that the Bitter End of your Anchor Rode is secured to the boat. Or it will be all for naught on anchoring. LOL
Reminds me of the old charter boat tale they tell in the BVI's about the couple that called in on the fourth day of their charter saying:
"We've chartered for a week but they only gave us three anchors...can you bring us enough for the next four nights?" (G)
|07-14-2007 10:13 AM|
Originally Posted by sanctuarysam
Good Luck and all the best,
|07-14-2007 10:07 AM|
Originally Posted by sailaway21
inquiring minds want to know.
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