Real Anchor loads

This months Practical Sailor ran a test in a spot with winds of up to 30K,but in protected waters,so there was no surge load.

At 3-1 (40ft sailboat)the max load veering was 1200-1400lbs.

At 7-1 down to 900lbs. 10-1 was best.

So the anchor has to handle fairly light loads.Even on power boats with higher windage.

The chain tests became bar tight as the boat slewed side to side.

With such light loading perhaps many folks are using line that is too thick to stretch,increasing the shock loads the boat must suffer?

The second problem they pointed out was Burying anchors really DO dig in.

In heavy weather, a trip line on a buoy would reduce the recovery loads on the shank.

WE use a buoy every time as it makes the anchoring picture easier for the next arrival.



FF

The trouble with an anchor bouy/tripline is it can get tangled in running gear on a tide change (and cause 'unanchoring').

But I can see some real advantages to using a trip line. For one it tells you exactly where the anchor is rather than having a spotter on the deck point to where the rode enters the water. I can't see the rode in the water from the helm so the admiral has to scout for me. Another reason of course is to dis-lodge it if necessary. However I've never had a problem freeing an anchor, maybe I've just been lucky.

One problem though is retrieving the trip line and having to untie it from the anchor, especially on a bouncing deck.

I haven't used one but will consider it.

FF,
"power boats with higher windage." An overstuffed sundeck w a big tent on top ....yes ...but I would think most trawlers like an IG would'nt have as much as a sailboat w masts and all that rigg'in. And boats like ours w/o a FB would have much less.

When you say "bouy" you mean trip line? I may start anchoring from the stern w a bridle and I think the trip line w an orange bouy may help tell the next guy into the anchorage that I'm stern anchored.

I agree about the stretch but I think you over stress that one. If stretch were a big deal all chain rodes would out.

FF writes "Burying anchors really DO dig in.". Depends on the bottom much more than the anchor but you use the expression "burying anchors"..... other than a Navy anchor what anchors are non burying?

Fred I'm impressed that you use a trip line all the time. With our deep and small anchorages w 23' tides our trip lines need to be quite long ...100' at times. I need to carry two trip lines. And in shallow water at low tides our trip line bouy may not be anywhere the anchor. And if I guess wrong about the length the bouy could be try'in to pull the anchor out.

jeffnick said:

The trouble with an anchor bouy/tripline is it can get tangled in running gear on a tide change (and cause 'unanchoring').

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We use a trip line about half the time we anchor and have never had it come anywhere close to the running gear even when the wind or current moves js fairly close to the float. And certainly not when we're retrieving the anchor. We use sinking line and take up all the slack when the line and float are deployed. So the float sits directly or almost directly over the anchor the whole time depending on the state of the tide.

Our trip line is simply tied (bowline) to a shakel on the anchor .

The line passes thru an orange buoy ring and a small lead for sampling the bottom is at the bitter end.

This allows the ball to float directly over the anchor,a boat hook grabs the line if required..

With the anchor on deck,the lead line is always handy.

FF

Seems to me that when the tide comes in you guys won't be able to see your trip line float. just say'in

Unless you anchor at high tide ....and then at low tide the float/buoy would not be directly over the anchor.

But have no fear.....one would only need to wait for half a day for the tide to go out to retrieve the anchor.

No,we set the length of the trip line to allow for the tide range.

We have an "eye" at the bottom of the float. The bitter end of the line from the anchor is inserted through the "eye" and a one-pound weight is clipped to the line. As the tide rises and falls the weight will "adjust" leaving the float directly over the anchor. Regardless of tide height. That way we don't have a wandering float at low tide or a sunk float at high tide. And since the line is always held down by the weight, we don't have to worry about line floating around on the surface and getting snagged in a prop or steering gear. Now if I could only convince other boaters that our trip float isn't a "mooring bouy" for them to tie on...!

Giggitoni said:

We have an "eye" at the bottom of the float. The bitter end of the line from the anchor is inserted through the "eye" and a one-pound weight is clipped to the line. As the tide rises and falls the weight will "adjust" leaving the float directly over the anchor. Regardless of tide height. That way we don't have a wandering float at low tide or a sunk float at high tide. And since the line is always held down by the weight, we don't have to worry about line floating around on the surface and getting snagged in a prop or steering gear.

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Very clever, Ray. You've got to show me the next time we're at the marina at the same time.

That's serious anchoring gear Ray. I'd a never thunk. Is it a bit hard to handle? Just a regular trip line and float is right on the line of being too much trouble. But when I get my anchor stuck I'd be quite proud of myself. Ever happened to you?

Hey Marin......This guy's a mile ahead of us and we do'nt hear from him terribly often. Wonder what else he's got to share.

The "counterweight" system Ray describes can be quite effective. We don't use that, however. We simply javelin the float and trip line way out to the side of the boat just before deploying the anchor. Since we have to take the dog ashore once we get the anchor set we just dingy over to the trip line float, coil up the excess line leaving enough slack to compensate for the tide, and clip the coil to the underside of the float.

manyboats said:

That's serious anchoring gear Ray. I'd a never thunk. Is it a bit hard to handle?

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I use it without too much thought now, Eric. By the way, the weight I use is too large to fit through the "eye" of the float.

Ironically, I've never had to use the trip line to break the anchor out. That's why I always use it.. Murphy's Law, ya' know!

Originally Posted by manyboats
That's serious anchoring gear Ray. I'd a never thunk. Is it a bit hard to handle?

Marin wrote...
The "counterweight" system Ray describes can be quite effective. We don't use that, however. We simply javelin the float and trip line way out to the side of the boat just before deploying the anchor. Since we have to take the dog ashore once we get the anchor set we just dingy over to the trip line float, coil up the excess line leaving enough slack to compensate for the tide, and clip the coil to the underside of the float.

Giggitoni wrote...
I use it without too much thought now, Eric. By the way, the weight I use is too large to fit through the "eye" of the float.
Ironically, I've never had to use the trip line to break the anchor out. That's why I always use it.. Murphy's Law, ya' know! Ray
__________________
Or...guys...you could save all that kerfuffle by just having an anchor with a special trip slot one can use when in the situation where one rarely does foul something in or on the bottom...have you heard of it...I'm sure you have...? It makes all that stuff above totally irrelevant and unnecessary. 'Course if you find all that frigging about fun...well that's another matter...
....He he he

Fouled in Cape May ,right behind the Hooligan navy (USCG) on a huge 1 1/4 steel cable.

Didnt bother the hud windlass,but new 5/8 nylon began to pull apart.

FF said:

Fouled in Cape May ,right behind the Hooligan navy (USCG) on a huge 1 1/4 steel cable.

Didnt bother the hud windlass,but new 5/8 nylon began to pull apart.

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Interesting...only time I've fouled an anchor bad was out in front (oceanside) of the Cape May Coast Guard Training Ctr on an old cable around 1.5 inches in diameter. Had 2 guys pulling by hand and they almost had the bow of my 23 foot sailboat underwater!

Wonder if all the old cable laying on the bottom is from the days when it was a Navy Air Station.

Peter B said:

[/I] Or...guys...you could save all that kerfuffle by just having an anchor with a special trip slot one can use when in the situation where one rarely does foul something in or on the bottom...

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A trip line only trips the anchor when you pull on it. Attaching the rode to a shank slot can trip the anchor when the boat pulls on it. Like at 3am when the wind shifts. I prefer to retain control of when our anchor backs out of the bottom.

psneeld said:

Wonder if all the old cable laying on the bottom is from the days when it was a Navy Air Station.

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That's the issue here. Lots of the bays had logging operations on them at one time. Old lengths of cable, pipe, you name it ended up on the bottom along with waterlogged logs. All sorts of anchor-snagging stuff.

Insurance is usually to protect the "other" guy.

Using a trip line is insurance for the boat.

FF

Back to the topic of anchor loads...

I just bought 100 Metres (330Ft) of 10mm chain rated at a WLL of 1 ton to connect to my 35Kg Super Sarca. The plan is to connect the Sarca to chain via a long 12mm (16mm pin) long D shackle due to anchor shank shape to 10mm bow shackle (rated 1.5 Ton) with no swivel. However I can't find a long D shackle of that size locally rated at greater than 0.6 Ton. Is that an issue in terms of realistic anchor loading? Gemma is 42' and 13.5 Tons

Marin said:

A trip line only trips the anchor when you pull on it. Attaching the rode to a shank slot can trip the anchor when the boat pulls on it. Like at 3am when the wind shifts. I prefer to retain control of when our anchor backs out of the bottom.

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He he..I knew you'd say that. You are wrong, but I don't know what will ever convince you, so ...ok...I officially give up on that one...

Peter--- You don't have to convince me that I'm wrong. I'm wrong lots of times. You have to convince the people who've had this happen that they're wrong.

Gemma,
I do'nt know why you need a long D shackle. I looked at the Sarca site pics and can't imagine why a conventional wide D "anchor shackle" won't work. Does it have something to do w the slot? I use a trip line and put a galv bolt through the slot of my Manson Supreme thereby keeping the shackle at the end of the shank in the usual way.
It may be a long time before you put over 1.5 tons load on your rode but it may be next week. Can you call Rex at Anchor Right? Peter how about help'in your mate out here?

manyboats said:

Gemma,
I do'nt know why you need a long D shackle. I looked at the Sarca site pics and can't imagine why a conventional wide D "anchor shackle" won't work.

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We use a conventional anchor shackle with our Super Sarca.

Manyboats and Bobofthenorth, thanks for your replies. The reason for the long D shackle is that I happen to have one but it is rated at 0.6T which fits and I bought a normal D shackle with a 16mm pin rated at 2T but its not wide enough to slide over the Super Sarca shaft So I figured I would have to see if I could get a higher rated long D shackle. I didn't know they also make wider ones. I'll go and explore that. Thanks again.

Gemma: Here's a source for some specialized shackles:

Specialty Shackles

Sure, no problem Eric. Jan you got yourself a pretty heavy anchor there, but as everyone seems to agree heavier is better than light when push comes to shove. Better still if it is a heavy version of a really good anchor.
You need a 12mm stainless long D shackle because you need a size above the chains gauge, and also dictated by the anchor size. The long D shape, and being stainless means the sliding slot mechanism works properly. A short or galvanised shackle might jam, and not work when needed. All info here.....
Super SARCA Anchor No 8 - Galvanised Anchors - anchorright.com.au

Marin said:

Peter--- You don't have to convince me that I'm wrong. I'm wrong lots of times. You have to convince the people who've had this happen that they're wrong.

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Not really Marin, because what I really have to counter is the misinformation they have fed to you, and which unduly influenced you. Why I say that is they really could not possibly know why their anchor dragged - unless, that is, they were down there with tanks on watching as it happened. All they could report is they dragged, and they happened to be swinging on Manson Supreme slotted anchors. However, as we know there are many other factors which can cause an anchor to drag - many do all the time, and without slots in the shank. Poor holding bottom, poorly set, insufficient rode out, too light chain or rode for the weight of the boat, or even just conditions just too overwhelming for any anchor to cope - the list goes on.
So they dragged, and like many poor workmen, maybe found it convenient to blame their tool. What I do know is that if they were in a blow, (where dragging matters), then no matter how the tide changed or the wind shifted, there would always be too much tension on the rode for the trip mechanism to come into play. The shackle would be right at the end of the shank, just like any other anchor. Sorry, but I can't put it any clearer than that. Bottom line - there is no way they could know their anchor slot triggered - they just surmised it did, but in conditions which would make that impossible, insofar as it is possible to say anything is possible or impossible.

Peter I can see why you are frustrated.

I'll try and present Marin's point of view that is basically my point of view as well.

When the wind changes 180 degrees many (but not most) anchors will revolve while rotating around to the new "heading" all the while staying buried or at least set. Even anchors that usually do this cannot be depended upon to do that all the time and most anchors will break out and reset. So if your anchor stayed buried ......fine but most wo'nt so will need to re-set.

But I think Marin feels his anchor will stay buried and his message to you is basically "why should I want an anchor that will positively break out when I HAVE an anchor that probably wo'nt". And I think he has a good point assuming that he has an anchor that will stay buried.

Since most anchors will break out anyway it makes no difference if they have the slot and break out because of that or break out because of anchor design or bottom conditions.

BUT whatever anchor we use if it dos'nt break out we are better off so why shoot ourselves in the foot and use an anchor with a slotted shank that is guaranteed to break out and insure that we need to depend on that anchor resetting when there's a good chance that's not necessary. Of course if you have an anchor that ALWAYS resets there would be no problem. But what Marin is saying (if I'm reading him right) is.......why ask for it. Why lower one's odds of staying hooked to the bottom.

I use a trip line on my Manson and put a bolt in the slot that insures that the shackle on the rode stays at the end of the shank. My trip line goes UNDER the roll bar so it will pull back instead of basically straight up. I think that up's my chances of retrieval. And if I buy a Sarca I'll do the same w it.

I sincerely hope none of this offends either you or Rex.