SailNet Community banner
1 - 5 of 5 Posts

·
Registered
Joined
·
275 Posts
Discussion Starter · #1 ·
1968 Hinterhoeller HR 28 sloop with an 8.5 foot beam, presents a smallish surface area even for a 28 footer. We almost exclusively daysail, but this year plan take occasional overnights that will involve fair weather overnight anchoring in north shore of Mass.

Our rode tackle is 15 feet of 1/4 inch chain and 175 feet of 3/8 inch nylon 3-strand, with a breaking strength of 4200 pounds.

I am trying to reconcile that 3/8 line is enough. It simply feels too small, yet May 2012 and September 2004 articles in Practical Sailor magazine indicate that even in a 60 knot squall, the ABYC estimates the load on the rode for a boat my size around 2200 pounds. Other respected sources estimate less load in 60 knots, some way less.

Any thoughts? I would especially appreciate citations from any other sources on the subject of loads on rodes. Thanks.
 

·
baDumbumbum
Joined
·
1,142 Posts
If you are worried about the size of your ground tackle, it is too small.

Not on paper perhaps, but you need to balance the (inconsistent) numbers against the consequences of failure against the value of peace of mind. It's not really about wind speed and frontage. You aren't towing this boat on a freeway. It's about the wave action kicked up by that 60kt squall, and that's a function of bottom depth & profile, wind direction, tides, length of blow, prevailing wave pattern before the blow, and so on. And the motion of the boat is dynamic, not a static pull. Even harder to calculate the forces involved.

So generally boaters rely on heuristic rules for rode sizing. By that rule, or rather those rules (cuz they also change from here to there), your chain is the right size but should be a little longer (length of boat is a standard recommendation); the nylon line should be twice the diameter of your chain, so 1/2". That actually makes the rope nominally stronger than the nominal strength of the chain, but then chains don't chafe or melt or lose elasticity over time. Nylon 3-strand is cheap and light: not the place I would shave corners. If bulk is a problem, it might be worth paying a bit more for one of the 8-plait braided anchor lines. They are slightly stronger, have better energy absorption, and pack much tighter than 3-strand. I'd still choose 1/2" diameter.:)
 

·
Master Mariner
Joined
·
9,410 Posts
Personally, I would take it up to 7/16" or even 1/2", not for strength, but for chafe (should it get tangled around something underwater) and ease of handling.
It's never really about the actual strength of the gear, but the elasticity and/or weight. Our new half inch BBB chain is only rated at about 4500# for a boat around 77,000#, but at 3# a foot of weight and our nylon snub line, the chain is more than adequate, as was the 3/8ths chain we are replacing.
This is one of the reasons I feel hi-test chain is a complete waste of money; not only is it not actually strong enough to hold the boat, anchor to stem in extreme conditions, it is about 1/3 lighter than bbb per foot, which actually defeats the whole point of chain and reduces it's effectiveness.
 

·
Registered
Joined
·
253 Posts
+1 on the extra chain. 30ft should be about right in your situation. Another important aspect of the chain is forcing the anchor to stay oriented in the correct position and help it set on short scope.

Do you tie off to one cleat? Both cleats? Use a bridle? Is there a bow spirit to contend with?
 
1 - 5 of 5 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top