|Topic Review (Newest First)|
|03-22-2010 09:09 PM|
|Capttman||My rule of thumb is two boat lengths of chain and 200 feet of rode proves to be good on the east coast, Caribbean, and the Bahama's|
|03-20-2010 07:45 PM|
|sailingdog||Glad to help Walt.|
|03-20-2010 04:19 PM|
All good and valid points. My braided may be 5/8th and I gust didn't recall it without going down to the boat. As you point out as the rode ages and wears you need more of a margin. All the horror stories I've encountered that deal with rodes failing are due to chafing in a storm. While a heavier rode helps, chafing gear and being able to keep it in place and if necessary change it under load appears to be essential.
As for cleats I haven't heard of failures from anchoring loads. I just became aware of the possibility when doing the calculations. My installed cleats are two-bolt cleats on the gunnels which are great for mooring lines.
Where cleats have a record of failing is when towing. Either the bolts shear (first one then the other) or they pull out some of the deck. With a deck stepped mast I can't put a line there. I could rig a bridle to the winches but I went for a robust deck cleat instead one which also serves the anchors. Thanks for the advice.
|03-19-2010 11:18 PM|
Personally, I'd recommend that you go up to 5/8" nylon for your rode. This is for two reasons. First, the rode's parts will all be more evenly matched in terms of working strengths. Second, a 5/8" rode gives you a lot more protection from chafe damage. BTW, I use a 5/8" rode on a boat that is about half the weight of yours.
On your boat, I'd think the 1/2" nylon was the weak point, not the cleats, unless the cleats are severely undersized.
Originally Posted by Waltthesalt View Post
|03-19-2010 10:38 PM|
I sail a Cal 29. 8,000# unloaded. Here's the anchors and wind speed calcs:
Working Anchor: (to 30 kts) Bruce 10KG, (sand, mud, gravel)
Storm Anchor: (to 45 kts) Fortress FX 16 (sand, mud with flukes adjusted)
Stern Anchorlunch hook kedge) Danforth 15# (sand, mud)
Back-up anchor: folding SS Northill (sand, gravel, rock, weed)
Tandem Anchors (theroetically to 80 kts. or surging) Fortress/Danforth I mad up a chain arrangement to do this.
Agree that Hinz is dated especially on anchor types with all the new anchors out there. It served the era of technology on my boat and was a good source for load/strenght/calculations. Id doesn't cover cleats all that well and I found out was that my cleats were the weak point in the system. When you check out shear stress for threaded ss bolts it's quite low. If you can get the cleat stress on the non-threades shank you can handle a lot more. The tables are hard to find. I put in a larger cleat with 4 larger diameter bolts and a pretty large 1/8" ss backing plate to cover the calculated stress.
|03-19-2010 10:11 PM|
While Hinz's book is fairly good, it is a bit dated and would benefit a lot from a revision. BTW, the rodes you describe sound quite a bit weaker than what I'd recommend. What size boat are you anchoring with a 1/2 nylon rode.
Originally Posted by Waltthesalt View Post
|03-19-2010 09:48 PM|
If you want a technical reference the most difinative that I know of is "The Complete Book of Anchoring and Mooring" by Earl Hinz.
In the Pacific Nortwest we have deeper water. I carry two separate rodes and anchors in the bow. On starboard is a 350 ft rode made of 1/2” line with 37 ft. of ¼”chain and a swivel. On the port is a 250 ft. rode of 1/2” braded line and 18 ft. of 3/8” chain. The strength of the latter rode is about 40% greater than the former. Both rode arrangements meet the manufacture’s recommendations for both my Bruce and Fortress anchors. A spring loaded link on each rode allows anchors to be switched between rodes. The Fortress is normally attached to the 350 ft. rode with the Bruce is normally attached to the 250 ft rode. The 250’ rode is the normal working rode for anchoring in waters about 30 ft. and for higher winds when the full holding power of the Fortress may be reached. The longer rode allows anchoring in waters up to 50 ft. and up to to 70 ft. with the killett*. For deeper waters the rodes can be attached end to end.
Each rode is in its own line locker in the forepeak with separate hawsepipes. As the original chain locker was large I divided it into two with lift out panels in the chain locker.
*I use a 20# downrigger ball and 80 ft of floating line serves as a killet or sentinel. The ball is attached to the anchor line with a bronze device called a “rode rider” and is lowered down rode. The killett increases the anchor’s holding power heavy weather; allows anchoring with short anchor rode scopes; helps keep the anchor line from being run over and reduces jerky motion with surging conditions. The normal practice is to lower it ½ way down the length of the rode.
|03-19-2010 03:55 PM|
|Livia||We are definitely using our manual windlass to hoist that! I wouldn't think you would need as much chain around here as we have and could use more rope. I was mostly commenting on length.|
|03-18-2010 04:34 PM|
Originally Posted by Livia View Post
Your reply, plus the other replies, confirm my hunch that 200' of rode is not enough. I'll be looking at least 275' plus chain. Funny enough, the chain that came with our current rode is thicker than anything I have used before.
|03-18-2010 02:45 PM|
We have 120' of chain connected to 150' of rope and in the Gulf Islands we find that we are most often on the first 120' of chain only both because of nice depths and swing room limitations BUT if we only had that we would be limited in ways we aren't comfortable with. Knowing that we can go to deeper anchorages when the popular shallower ones are full, or that we can let out a lot more additional scope is nice.
Still, I think that you could probably cruise in the islands on 200' for a while (watching your depths) and then decide later whether to upgrade and how much depending on where you go.
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