Elessar
Well-Known Member
Sadly they don’t do chain. They gave me the number of a sister organisation in Wolverhampton. Who are not doing chain due to maintenance. Ring back in a month.Wessex galvanisers, Eastleigh. Southampton
Sadly they don’t do chain. They gave me the number of a sister organisation in Wolverhampton. Who are not doing chain due to maintenance. Ring back in a month.Wessex galvanisers, Eastleigh. Southampton
Fab thank you.He's down in the old Eastney Pumping Station building in Henderson Road at Eastney, can't recall the name. Google Earth street view shows Portsmouth Steel Fabrications I think. I don't know which galvaniser he sends it to and I've not taken chain in there, just other bits of steel for a trailer.
Thanks. It’s a british boat and mixed chain rode. Why do you think the chain looks big? It’s a 40ft flybridge. What do others use size wise?Measuring chain is fraught with problems, especially old (worn) chain.
Take the windlass apart, its easy (check the manual) and the gypsy, chain wheel is in 2 parts. Look at each part and the chain size is engaved on one of the surfaces of the gypsy. If its 10mm it will also define if its an ISO or a DIN chain. There is an outside chance that if your boat is American then its imperial chain. An Imperial chain will NOT fit on a metric gyspsy. If its an imperial chain again it will be marked on the gypsy but note that imperial BBB, G3 aka G30, G4 aka G43 and G7 are all different sizes of link. There is some overlap and some gypsies are forgiving - just be careful. If you decide to go the 'new chain' route then take the gypsy to the chandler and match the chain to the gypsy by wrapping chain round the gypsy. If its a good chandler (they are few and far between) then the chandler will be able to mount your gypsy and run the length of chain you want to buy through your gypsy, proving to you the chain matches the gypsy.
You are a bit far away but the best galvaniser for chain now would be Highland Galvanisers based in Cumbernauld. The MD is a member here, does re-galvanise chain and being a yachtsmen is sympathetic to your needs. The issue is getting the chain to him and the idea of canvassing other members and getting a batch together will save money - but involves someone arranging it all. If your chain is painted the paint needs to be removed prior to galvanising - a wire brush on the end of a drill is one way - dragging the chain behind a car on a beach is less effort (but might need the wire brush as well).
If you cannot match chain to gypsy, or gypsy to chain - be aware - new gypsies are extortionate and you might then be better buying a new windlass rather than fitting a new gypsy to an old windlass. Looking at the picture of your boat 10mm does seem large - but maybe weight is not an issue and maybe also you have a mixed rode. If its an all chain rode 10mm chain is significantly heavy and you might need a wheelbarrow to move it from boat to someplace else.
Jonathan
'The question of using a stainless steel shackle with galvanised chain and anchor comes up often.
Whenever two dissimilar metals are immersed in seawater there will be a galvanic effect. In this case it is the galvanised metal (especially the zinc coating) that will corrode. However, the effect is influenced by the ratio of the surface areas of the two metals.
In this case we have a very small amount of stainless steel with a very large amount of galvanised steel. So the extra corrosion on the galvanised steel is very slight. In most cases the effect is hard to detect or slight so that the few links of chain close to the shackle show some slight extra corrosion and need to be cut off every few years.
Occasionally a link or two of the chain close to the shackle can show more rapid corrosion. This is caused by poor electrical contact between the links of the chain. In the worst (theoretical) case the stainless steel shackle can be electrically connected to only one link of chain. This creates the situation where the surface area of the two metals is similar and so reasonably rapid corrosion of the last link or last few links can occur. However, it will not (or only imperceptibly) effect the whole length of chain.
So a stainless shackle is OK to use with galvanised chain and anchor providing you keep an eye on the last few links of chain.
Of greater concern is the quality of the shackle used to join the chain to the anchor. Make sure it is not a “no name” shackle, but is manufactured by a reputable brand and has a quoted load rating (SWL and UTS). Make sure the rating of the shackle exceeds the chain, you don’t want such a small component to be the weak link. It is actually worth having a shackle that considerably exceeds the chain rating. This is because with side loading the strength of the shackle will be much less than the published rating.
I use the largest galvanised Crosby 209A shackles that will fit. These are high strength galvanised shackles, but there are similar products from many companies.
In over 30 years I have never had a problem with using stainless shackles on galvanised chain.
www.solocoastalsailing.co.uk
Thanks. It’s a british boat and mixed chain rode. Why do you think the chain looks big? It’s a 40ft flybridge. What do others use size wise?
'[...]
. I see no reason why Poignard cannot end for end his chain and use a Crosby G209 A shackle.
Thanks. I usually anchor in shallow water so mostly use only chain.If you had been carrying 70-100m of 10mm chain you might have found the weight excessive - with a mixed rode - not an issue.
However if you use the rope frequently (because you do not have much chain) then every time you retrieve the rode the rope sits in the bottom of the locker, well sodden with sea water. The chain sits on sodden rope and some of the water evaporates and condenses on the chain - its a recipe for corrosion. Ideally you want to separate rope from chain and ensure the locker has good drainage.
I would not use a stainless shackle and agree with Noelex and would use a Crosby G209 A shackle (they meet a Grade B standard in the US). They are possible the best you can buy and are available from Tecni in the UK (and presumably other distributors). If the shackle locks up in the slot in the anchor (not uncommon) the shackle WLL is reduced by 50% if the side load is 90 degrees and reduced by 25% if the side load is 45 degrees. The only shackles of a comparable quality (of the size you would need) are from Campbell in America and as far as I know are not avaliable in the UK. If you buy 'no brand' shackle - don't be surprised if they fail, if they are stainless they might simply distort, if they are gal they may simply break - buy shackles embossed with a reputable brand.
Note if you buy CMP Titan Black Pin shackles then the WLL is imperial short tons not metric tons.
A Crosby Grade B shackle negates any need for an enlarged link as the shackle is far in excess of the strength of chain to which they can comfortably fit. However just because the shackle fits the chain does not mean it will fit the slot in the anchor - and not lock up. Check and check again. I see no reason why Poignard cannot end for end his chain and use a Crosby G209 A shackle.
Jonathan
An interesting take.If you look at the pictures that Vyv posted of the 2 chains flogging the seabed it is interesting that the 2 pictures, or the impact of the flogging of the 2 chains is almost identical even though one chain Vyv's is 8mm, on a 35' yacht, and the other 12mm (on a 55' yacht). Despite the 12mm chain being seriously heavy (and the yacht possibly also heavy and slow to veer (effects of inertia) the 2 chains appear to have behaved similarly. To me this underlines that the chain spread sheets of chain size (weight) vs vessel length seem to be about right.
We, personally, have sacrificed chain weight (and the inherent catenary) and replaced it with elasticity of a bridle - as we are using a 30m bridle we are 'in effect' using a mixed rode (but in a different format to a conventional mixed rode). Your rode however needs strong cordage, equivalent in strength to the chain, we don't rely on the cordage so ours is thinner and more elastic.
Summarising - we believe in the mixed rode, so are biased.
And summarising my opening paragraph - if the chain is sized correctly, along the lines of the spread sheets then heavy chain will lift off the seabed as easily as smaller chain (unless you step outside the spreadsheets).
To me, or us, the chain is simply there to join anchor to vessel. It offers little help to the anchor. A good anchor should work by design and should work whether its joined to the vessel with piano wire or 12mm chain.
I have a few caveats. The chain actually reduces the performance of a good, or bad, anchor as the chain resists burial. If the chain resists burial then it hampers the anchor burying. Large shackles, lots of shackles, big swivels, swivels themselves also hamper burying.
Rather than heavy chain I'd advocate a decent anchor, one that has been tested for its holding capacity (of which there are many to choose from), Rocna, Supreme, Ultra, Excel, Kobra, Spade and as small a chain as you can get away with, G70, G80 (like ours), even G40 (if it allows you to down size ( - you still need the strength). Dispense with anything large in the rode, shackles etc - use a sensibly sized Crosby - so choose with size in mind and install a decent snubber.
I'm not condemning a mixed rode - my only caution is that it needs to be beefy, for strength, and beefiness reduces elasticity.
Our mixed rode involves use of a bridle and bridles reduce veering - an advantage you don't get with a conventional mixed rode. Our arrangement also improves scope, the ratio, and as a result of the arrangement reduces the impact of horsing, seesawing in chop - so our mixed rode does 'more' than a conventional mixed rode.
Sadly most of this practice needs to be considered when a vessel is commissioned or when you need a new windlass or chain. No-one is going to dump good 10mm chain for 8mm and few are going to buy a new gypsy - its too costly.
Jonathan
An interesting take.
I don’t however understand how in can be true.
If you have the same length of chain and the same pulling force, ie windage weight of boat etc the light chain must lift further off the seabed than heavy. How can that not be true?
I have no option but to use a delta by the way due to the boat configuration.
My boat could probably carry your boat and still not sink ..... it's officially unsinkable.Just remember that his boat is a relatively light catamaran, where every extra ounce of weight carried is disastrous. For those of us with proper boats, which can carry some extra tins of beans without sinking, use normal sized anchor chain, and enjoy the benefits of catenary. ???
This may help. It was a test done by an Italian sailing magazine looking at the effects of rode weight on the anchor’s holding ability. They tested the holding power achieved with all chain, a combination of 10m of chain and the rest rope, and finally an all rope rode. This was done for three different scopes 3:1, 6:1 and 10:1. It was a 12kg anchor (Delta from memory) and 8mm chain.An interesting take.
I don’t however understand how in can be true.
If you have the same length of chain and the same pulling force, ie windage weight of boat etc the light chain must lift further off the seabed than heavy. How can that not be true?
I have no option but to use a delta by the way due to the boat configuration.