Storm Preparation

[AnchorageGuy]

Craig, Sorry but no confusion in my posts. The inner core of polyester will generate heat, as will nylon but not to the extent. The core will virtually melt if enough force is applied, as will nylon but not to the extent, and there will be no indication until failure since the core is not visible. This in my opinion makes for concern when using braided line for storm conditions and to anchor in severe conditions. Braided dock lines are found everywhere. In "several" hurricane situations at marinas I can tell you first hand (or with my own eyeballs) that the braided lines failed at a rate of about two to one compared to three strand nylon and almost no braided polyester lines survived as dock lines in hurricane conditions at the dock. This is not from any published reports by retailors, rode manufacturers or anchor salesman but from standing amidst the destruction after the storms. And that is storms plural and not in one instance.

[Pura Vida]

Gord, I guess that I am not seeing that. They may be inconsistent in the presentation of the discussion but the eight articles I have read say pretty much the same thing. New, oversized nylon is their suggestion for storm anchor and dock line. In three cases they suggested possibly using polyester and nylon.

[hellosailor]

Perhaps all polyester is not created equal.

Ditto for nylons.

[seafox]

Mmmm, what about Spectra?

[Alan Wheeler]

Spectra has no give. A good hard abrubt pull will snap spectra and most other of those ultra low stretch high strength ropes. It is the biggest downfall of them.

In regards to the lines. You need a rope with plenty of stretch that can absorb the shock. Abrasion is and should be the biggest enemy of any line. If the line fails due to frictional heat build up internaly, then it simply was too small for the job at hand in the first place. If spec'd right, then protection from abrasion is the major concern.
ALL lines generate heat. The amount of heat is proportional to the amount of stretch the line has. That does not always equate to nylon or poly as being better than the other. It does depend on the quality of the line in manufacture. Quality can result in less frictional wear, ie multi plate beign better than 3 core. The differences in the windign of 3 core can also help. What tend to be the greater cause of heat failure issues is more due to the lessening strength in relation to elevating the temperature of either materials. I believe (if I have it the right way around) that polyesters strength decrease faster than Nylon as the temperature rises.

[ASkok]

Interesting thread. Anyone know the relative stretch for nylon 3 strand vs. polyester brait?

[rtbates]

Eliminate chafe.

As much as possible, use chain for the actual attachment point at both the vessel and the dock/piling, etc. A loop through the bow roller for anchoring/mooring. Shackle the mooring/anchor line to the chain loop with shackles and there will be no chafe.

For anchoring/mooring, try by the stern. Jordan Series Drogue - Mooring and Anchoring
That's my quote at the beginning of the article.
Eventually I'll be able to use the straps that I'll be attaching to the stern quarter as vessel attachment points using shackles. No chafe whatsoever. The straps are for attachment of a Jordan Series drogue.

[schoonerdog]

I see the logic, especially with a typical aft cockpit monohull, but would say using that same logic, it definitely doesn't apply to a catamaran. While monohulls present a cabin top which starts a few feet back from their bow and a solid foredeck, most cats present only a thin net and slender hulls until 1/3 of the way back when the bridgedeck structure begins to present itself, with the majority of the bridgedeck structure starting beyond 50% of the way back. Further aft is an enclosed cockpit which would be, in terms of the article, our biggest "feathers". Often beyond that is an even larger arch. Therefore, according to the logic of that article, cats should definitely anchor from their bow. I wouldn't necessarily carry that logic forward and say they should never use a drogue, but I've heard of cats sailing with an apparant comfort using a rogue and then becoming suddenly unstable and being thrown. Your article might explain that behavior.

[Brent Swain]

Run shorty pieces of heavy chain over the fairleads , and around the dock rails or pilings , with heavy rope in between them ,and forget about chafe.
Brent

[dennisail]

Originally Posted by craigsmith

For possible consideration of why nylon may not be a good idea in your anchor rode in extreme conditions, and polyester the better option, please study the following article by Steve Dashew:
http://www.setsail.com/_storefiles/71.pdf

That article alludes to doubling the strength if the rode is double as long. That has to be wrong. If you double the rode in parallel it would double it strength. Making it twice as long would surely help with shock loading but the way it is written is misleading. Would would happen if you made your rode 4 times as long and 4 times smaller in diameter? It would break for sure, accoring to the acticle it should equal out becuase of the increase in length. 4 times smaller means 4 times weaker, but becuase its 4 times longer it can absorb 4 times more energy. The extra stretch would never make up for it. Sounds like a red herring.

[GordMay]

Originally Posted by dennisail

... 4 times smaller means 4 times weaker, but becuase its 4 times longer it can absorb 4 times more energy. The extra stretch would never make up for it. Sounds like a red herring.

Four times smaller (diameter) may actually make about sixteen times weaker.

Breaking Strength, & Working Load Limit varies approximately as the square of the diameter.

[dennisail]

I was talking about CSA - Cross Sectional Area

[cat man do]

Originally Posted by GordMay

NEVER PLAN TO STAY ABOARD YOUR BOAT DURING A HURRICANE!
Storm conditions are VIOLENT, and tornados are often associated with landfalling hurricanes. First and foremost: safeguard human life!

.

Recently had a taste of a potentual cat 4 Cyclone, sure not a hurricane or tornado, but plenty of wind.

Because of where we were [ in Vanuatu] there were plenty of palms and coca nut's, and that was deemed a bigger risk than losing the boat.

Flying sheet's of corrogated roofing Iron have cut people in half before and wind bourne debris has killed as well.

But if I had a bunker close at hand, well........................

Dave

[rtbates]

I totally forgot to mention what MY main storm preparation is. And that is to get Seraph on her trailer and the hell out of dodge. I know that doesn't apply to all you big boat sailors, BUT since the ability to get her away on her own trailer pulled by my own vehicle is why I bought Seraph and not a larger vessel, I thought I'd mention it.

[schoonerdog]

I've been through two remnants of hurricanes, never a direct hit. The first one was around 40 knots steady with gusts around 70. Nasty, dragging in the chesapeake mud. The second time I had learned my lesson, Hurricane Isabelle was predicted to be the first hurricane to hit the chesapeake directly in over 50 years, and the last one had made many of the lakes and islands we have now. I didn't bother with anchors anymore, instead putting the boat in a very sheltered nook and then took hundreds of feet of rode and chain out in three directions and secured them around 100 year old oak trees 20 ft up the banks and brought the chains back, shackled them together onto my sea anchor swivel and from that huge swivel brought 100 ft lengths of mooring lines back along both sides of the boat tied to the bow cleats and then brought aft and put around the two main winches. Finally I put huge rubber tubes around the spots where they came onboard as chafe protection. As an FYI, if you think you might need hurricane haulout, arrange for it ahead of time (like now) with a marina but make sure that the placement of your boat in the marina would be at least 20 ft up. Every marina in the chesapeake had no space when the hurricane was first predicted to strike, and many simply told us that if it hit directly it wouldn't do any good at their marina because they would be flooded and the waves would knock the boats off their cradles.