A genuine anchor question?

[Quandary]

I am an aged sailor from the generation which believed in big CQRs and long all chain rodes but also the benefits of keeping weight out of the ends of the boat, so please bear with me here.

Our boat current is a Moody S31, we carry two anchors, a 15kg. Spade in the anchor well and a 10kg Delta backup in a cockpit locker. Last week, in preparation for lift out, I took off the main anchor and chain, the bow of the boat rose by about 5", so I have now concluded that the anchor, chain and windlass in the bow locker must have a significant affect on the boats performance. The 15kg. Spade is on just under 50m. of 8mm. chain which is in two lengths joined in the middle by a Crosby C link, I am tempted to replace half the chain with about 60m. of 12 mm. multiplait nylon in the hope that it will improve performance both sailing and motoring?
Our cruising ground is the Scottish West Coast, where, with the exception of a couple of places like Canna or Puilladobhran ( insert your spelling corrections here), there is usually plenty of room, we try to anchor in about 5m. but 10 to 20m. is not unusual, not often any deeper. I know if I deploy the rope the boat dances around the anchor in light winds but I presume that with a new generation main anchor the removal of the chain will not really make much difference to security?

A second question; in close to 50 years, other than kedging when racing, I have only deployed our spare anchor once (at Canna when the old mandatory CQR on our Sigma 33 OOD refused to set in the thick kelp) so is their any point in the second anchor with a bit of chain and some rope, it can add little to the security of the Spade?

Correction, Chain is 8mm not 10 as stated in error.

 

[thinwater]

Another reason for a second anchor is in the odd case that you had to abandon the primary. It happens eventually. For this purpose, what you have makes sense, with a little chain and a good bit of rope.

The rest I will leave alone--it's and anchor thread concerning a region I don't know. I will only say that 10mm chain is massive for your boat. 8mm is more than enough.

 

[Tranona]

It is the 10mm chain that is OTT, but changing to the more normal 7 or 8mm would need a new gypsy. The 15kg Spade is also a bit heavy but better to have the weight there than in the chain. Whether you use part rope depends on how often you anchor in water deep enough to have to use the rope, although would guess that the combination of an effective anchor such as you have and heavy chain would not cause any problems with holding. However you may find your windlass won't handle rope or the change to chain very well.

No clear answer to the spare/kedge dilemma. Again it depends on how you use it. Your Delta would be a good replacement if you lost the Spade, but guess you don't use a stern anchor in the same way as you would if you were in the Med! On our boat there we used a big Brittany for a stern anchor when mooring bows to, but here I don't remember when I last used a kedge so have just a small Danforth with 6m chain and 30m rope.

 

[Cardinal]

I suspect that you might regret the change proposed to the bower rode which might lead to a need for more swinging room which is not always available even in less frequented anchorages. Your kedge might then prove useful to restrict swinging.

 

[Quandary]

Sorry, Sorry, correction, the chain is 8mm.

Hoping for some guidance on the boat performance with less weight in the anchor locker.

 

[JimC]

My boat is rather fine forward and I don't like to weigh her down too much. IMHO the best policy in this situation is to have an amply heavy anchor but cut down on the chain. On my 31 footer I have a 14 Kg Kobra on only 10 metres of chain plus 90 meters of 14 mm octoplait. This lets me anchor in up to 20 metres which has always sufficed when I've been up in W. Scotland. As the OP says the boat does tend to wander about a bit and in wind over tide conditions the boat can move back and forth over the anchor and potentially get the rope round the keel(s). This is easily circumvented by using an angel (mine is a 10 Kg gym weight that was an Aldi bargain) and letting it down to just lower than the boat's draught so that the rode falls down verically to below the keel(s). This also curtails the wandering about and makes the boat behave more like as if she was on all chain.

An angel is also handy when tying up to a harbour wall where having ropes long enough for the rise and fall of the tide would otherwise allow the boat to move away from the wall at HW. Two are ideal here but you can manage with one.

N.B. angel a.k.a. kellet

 

[scruff]

FWIW I sail a moody 34 in the same bit of the world as you. Currently we have 40m of 8mm chain and I am mulling over getting more chain to take it up to 60 or 80m. Like you say, there are few places without swinging room (Tinkers hole mainly comes to mind) but plenty of deep anchorages. The wind often seems to be in an awfy hurry too.If you are curious as to how the boat performs with a lighter bow, can you not relocate the chain away from the anchor locker to an ikea blue bag in front of the main bulkhead for a sail and see how you get on? My instinct is to say that these were built as heavy-ish cruising boats and the weight of the anchor &chain would of been factored in on the design board.

 

[NormanS]

I'm really surprised that removing the anchor and chain made so much (5") difference to the trim. You're talking about the weight of one person standing on the foredeck. Approximately 85kg.

 

[vyv_cox]

I'm really surprised that removing the anchor and chain made so much (5") difference to the trim. You're talking about the weight of one person standing on the foredeck. Approximately 85kg.

Me too. I swim around my boat a lot, both at anchor and on mooring buoys. I take a keen interest in the water line, particularly as I am scrubbing weed off. I have not seen any appreciable difference in water line with all the chain in the locker or with 40 - 50 metres of 8 mm chain out. The Sadler 34 is fairly fine in the bows, so might be expected to react quite a lot to weight up there.

 

[Quandary]

Well, I did take the boom off and remove the berth cushions at the same time but they seemed light compared to the wheelbarrow of anchor and chain I was heaving up the drive to the garage. I can just about lift a person but no way could I lift the barrow. The diesel tank was filled for winter and both water tanks are still full but everything movable is out except some ropes and the second anchor.

I will have another opportunity to check the change in trim after launch in the spring, it would be good if you are right and I do not need to change anything.

 

[noelex]

Quandary, you have 70kg in chain and 15kg in anchor. So reducing the chain weight is more sensible than trying to reduce the anchor weight. I agree with others that I would have thought this bow weight was an acceptable compromise for your vessel, but it is not my boat.

Replacing half the chain for rope will only have a modest impact on the anchor’s holding power, althogh there can be an effect in setting performance in difficult substrates. The main problem with the change is a reduction in abrasion resistance.

There are some dangers such as from old mooring/fish farm blocks, rocky substrates and unfortunately man made rubbish. It is amazing what is on the bottom in even relatively deserted anchorages. The risk is hard to quantify and varies significantly from one location to another so you will need to judge if the weight savings justify the extra risk.

There is also the problem of swinging differently to the majority of cruising boats that are likely to be on all chain rode, but in most of the Scottish west coast anchorages this will not be a significant problem.

The other option is thinner, high test chain, but this is difficult to source in sizes less than 8mm. Buying un-galvanised G70 -G100 chain and arranging the corrosion protection yourself is the only option that I am aware of. Maggi has suggested it will release 6mm G7 but I don’t think this has happened yet. You would also need a new gypsy, and the chain life is likely to be less.

A spare anchor is nice to have and I would keep the Delta in case the main anchor is lost. If stored in a cockpit locker there will be little effect on the saling performance, but make sure it is well secured.

Here is a scary photo to contemplate before making the change :

 

[Neeves]

I can sympathise with your story - I recounted it not long ago - but I decanted our 50m x 8mm into a box in the dinghy, took it to shore - to discover I could not lift the box - same, same!

We replaced the 50m x 8mm G30 with High Tensile 75m x 6mm of the same strength as the 8mm G30.

I would be surprised if you can tell the difference (if you reduce rode weight), because the differences will be small (but they will be there). If it was a racing yacht with decent instrumentation and the ability to record performance I think the improvement could be detected. As Norman said your rode is similar to having a man standing on you bow as you beat to windward, if you reduce the chain rode by half you will replace that grown man by a sylph like young lady on the bow, and though this might be more attractive - you will still have 40kg of chain + some rope. It might still be possible to detect any improvement (with that good instrumentation) but I doubt you, personally (and I'm not being derogatory) - no-one will notice the difference.

You actually do not mention a windlass, if you do not have one (and you are conscious of the weight of the rode when you retrieve by hand) - I would look at sourcing 6mm chain (but that is another topic - if you want to go that route, 6mm chain, there are other implications - I've been through it). If you have a windlass then the cost of a 6mm gypsy to replace the 8mm gypsy is a huge deterrent. Here in Oz, the cost of having my own HT 6mm chain 'made' was about 50% cheaper than buying standard locally made G30 x 8mm and because the galvanising is better, its a different process. (harder) is lasting longer.

Changing chain size will free up a lot of space wherever you store the chain (as well as reduce weight).

If you decide to retire half the chain, at the join, and add some rope - I'd add more rope than you will remove chain (it will give you greater flexibility). I would use the kellet - but I would have it arranged so that is touches the seabed - as this will slow the movement of the yacht in light winds. The other option, I think Thinwater calls it a hammerlock?, is to have the kellet independent of the rode and simply hanging such that is drags on the seabed (but you could do this with your spare anchor - just to make that 'friction break'). From memory light winds are not the regular occurrence in your cruising grounds to be a big issue ?

Again if you go the rope route and you have a windlass - make sure the rope fits the windlass.

I would concur - keep the spare anchor, you may need to abandon the current main anchor - but if weight is an issue - think of alloy - Fortress, apparently come up on eBay quite often in the UK.

I think the first thing you would do is to have a beefy(ish) man (or 2 sylph like young ladies) stand on your bow and check the difference again. 5" does seem quite noticeable - and if correct - you might notice performance difference. With the 2 young ladies - you can have one disembark to see the effect of half the rode. An alternative but maybe less interesting is to use water to simulate the weight of the rode.

Jonathan

 

[Quandary]

My thanks to everyone who took the trouble to reply,
The consensus seems to be that my concerns about trim and performance are exaggerated, I can accept that.
So I will follow the advice and stick with what I have, less trouble and expense and I concede that it is time I got the bee out my bonnet about performance, these days we motor half the time anyway.
A non contentious anchor thread wrapped up in 12 posts, I am claiming a world record.

 

[BabaYaga]

The main problem with the change is a reduction in abrasion resistance.

There are some dangers such as from old mooring/fish farm blocks, rocky substrates and unfortunately man made rubbish. It is amazing what is on the bottom in even relatively deserted anchorages. The risk is hard to quantify and varies significantly from one location to another so you will need to judge if the weight savings justify the extra risk.

I have a 16 kg Delta on a mixed rode of 20m of 8mm chain followed by some 45m 14mm anchor plait nylon – so not very different from what the OP is considering.
I find this a good compromise between holding/security on the one hand and weight (in the bow and for hauling by hand, as there is no windlass) on the other.
Regarding the risk of abrasion, I have found that I mostly do not have more rode out than 20m + water depth, in which case the nylon will not reach the seabed. If I do have more rode out, it will be in gusty conditions, which again will keep the rope off the seabed.

Edit: Sorry for the 13th post.

 

[dom]

My thanks to everyone who took the trouble to reply,The consensus seems to be that my concerns about trim and performance are exaggerated, I can accept that.So I will follow the advice and stick with what I have, less trouble and expense and I concede that it is time I got the bee out my bonnet about performance, these days we motor half the time anyway.A non contentious anchor thread wrapped up in 12 posts, I am claiming a world record.

Neeves describes the options well, but FWIW I disagree that your trim concerns are exaggerated. Accepting that my sailing formation was in racing, I still think 85kg on a relatively fine 31' bow + the windlass gear etc is nuts. Moreover, if 5" is even close to a correct waterline measurement that is seriously unbalancing your boat. May I suggest you get a big calibrated washing tub or something, place it on your bow, and start filling with water? Mark off the waterline at say 0, 20, 40, 60, 80, and 100kg. Look for a sweet spot and then re-balance to suit; 10mm chain is unnecessary (shorten or reduce) and don't forget any heavy items stored in your forecabin! Free your boat's bow and free its soul

 

[RupertW]

Neeves describes the options well, but FWIW I disagree that your trim concerns are exaggerated. Accepting that my sailing formation was in racing, I still think 85kg on a relatively fine 31' bow + the windlass gear etc is nuts. Moreover, if 5" is even close to a correct waterline measurement that is seriously unbalancing your boat. May I suggest you get a big calibrated washing tub or something, place it on your bow, and start filling with water? Mark off the waterline at say 0, 20, 40, 60, 80, and 100kg. Look for a sweet spot and then re-balance to suit; 10mm chain is unnecessary (shorten or reduce) and don't forget any heavy items stored in your forecabin! Free your boat's bow and free its soul

+1 but also do you have a water tank up front - many boats do and we find the trim noticiably different (3 or 4 cm?) with and without the 225l tank being full. In our case we tend to be down by the stern thanks to all the gear plus a both double bunks aft having tanks below them.

 

[Aja]

Quandry

Just to add to the discussion I started this thread http://www.ybw.com/forums/showthread.php?505565-Reducing-chain-size&highlight= in August to determine benefits of downsizing chain due both to weight considerations and the problem of getting 10mm chain down the hawsepipe without it jamming due to the small anchor locker. It may help.
Donald

 

[dunedin]

My thanks to everyone who took the trouble to reply,
The consensus seems to be that my concerns about trim and performance are exaggerated, I can accept that.
So I will follow the advice and stick with what I have, less trouble and expense and I concede that it is time I got the bee out my bonnet about performance, these days we motor half the time anyway.
A non contentious anchor thread wrapped up in 12 posts, I am claiming a world record.

Good call. We have two Rocnas and nearly 100m chain in the bow of a slightly bigger boat. Can’t remember the last time anybody overtook us going to windward under sail (race boats with black laminate sails excepted).
And as you know sometimes in Scotland you can be grateful for no compromise anchor gear

 

[Neeves]

Quandary,

I think there is an unwritten law that actually dictates that anchor threads must be left to live their life unattended by the OP.

I would be interested, as I am sure might others - when you get the opportunity I would be interested in a re-assessment of your trim and the effects of a man, or 80kgs, on your bow. I somehow don't think you will fancy wheeling the rode back to the yacht and dumping it on the foredeck - a man will suffice!

Jonathan