Best shape for chain locker?

[GHA]

Thinking tall and skinny is better than low and fat to stop the chain jamming? And is there by any chance a formula for space needed for 60m of 10mm chain?

TIA

 

[RupertW]

I can only speak about the dreadful shape of mine which causes the chain to pile up every couple of metres. It is deep and self draIning (good) but the windlass drops the chain onto the top of a slope down to the rest of the chain. So the chain simply rests on the slope and takes very little to reach the windlass and jam.

So my tips would be deep, self draining, and as long a fall as possible with no slope, and if you have any doubts and can afford it then slippery chain.

 

[vyv_cox]

This pic shows 50 metres of freshly galvanised chain in a tall chain locker, admittedly fairly large although only on a 26 ft motorsailer.


By contrast, putting the same length of chain in the flatter locker of our 34 ft boat requires chain shifting on two or three occasions.

 

[NormanS]

This pic shows 50 metres of freshly galvanised chain in a tall chain locker, admittedly fairly large although only on a 26 ft motorsailer.


By contrast, putting the same length of chain in the flatter locker of our 34 ft boat requires chain shifting on two or three occasions.

Yes, but freshly galvanised chain is always going to misbehave. Once it's been used a few times, and the excess zinc has worn off, it won't pile up like that. (Says he who has just had his chain regalvanised!).

In normal use, when the chain is pulled up, it's wet when its going into the chain locker, and even water acts as a slight lubricant.

 

[GHA]

This pic shows 50 metres of freshly galvanised chain in a tall chain locker, admittedly fairly large although only on a 26 ft motorsailer.


By contrast, putting the same length of chain in the flatter locker of our 34 ft boat requires chain shifting on two or three occasions.

At the moment mine just goes straight into the forepeak, tends to form a hill a bit but not quite as bad as that, once in a while on a rough passage it can fall over which is a pain to unravel single handed so thinking a thinner space will mean it can only fall a little and not jam,,, guessing a bit though.. as ever

 

[Kukri]

Merchant ships have tall cylindrical chain lockers. There is a formula for diameter of locker in relation to diameter of chain but it’s for stud link chain so it wouldn’t work for boats. None the less tall and narrow is the way to go I think.

There are formulae for chain weight and volume. I thought it was in Nicholson’s Boat Data Book but it isn’t so it must be in Skene’s Elements - “loan oft loses both itself and friend”... so I draw a blank.

 

[GHA]

There are formulae for chain weight and volume. I thought it was in Nicholson’s Boat Data Book but it isn’t so it must be in Skene’s Elements - “loan oft loses both itself and friend”... so I draw a blank.

Ah, of course, still a little bit of paper onboard John Vigor Boatowners handbook has 0.034M^3 for 18m of 10mm.

Wonder what footprint though...

 

[NormanS]

I'm sure that tall and narrow is an ideal to strive for, but realistically on a small to medium yacht, vertical height between the gypsy and the top of the pile of chain, is difficult to achieve.

 

[Cardinal]

I'm sure that tall and narrow is an ideal to strive for, but realistically on a small to medium yacht, vertical height between the gypsy and the top of the pile of chain, is difficult to achieve.

I agree. I have divided my chain locker with a stainless plate which sits across the narrower forward part and forward of which I Stow my first 30m of 10mm chain. The remaining 40 m thus has more height available to fall into from the windlass. 40 m is enough for most occasions but the rest can easily be pulled back into use if necessary. It just then needs to be stowed forward again after use.

 

[Kukri]

The best chain locker I have seen was built into the Shuttlewoods smack yacht Bird of Dawning by my old friend Chris Briggs, and it consisted of a part bulkhead forming a compartment a few inches deep, with a full width bulkhead behind it, running up to the deck with a vertical section of tongue and grooved boards run horizontally, quite slack, in hardwood channels with a finger hole in each. In the unlikely event of a jam, you could lift out the slats as far down as the blockage. I don’t recall that it ever did jam.

 

[Neeves]

If you go to chain makers websites, or at least some of their websites, they define how much chain is held in 'their' standard pail (or drum) - because if you desire they sell in drum of pail lengths.

I think Peerless or maybe even West Marine list the amount per pail - but you will need to be able to convert from imperial to metric.

As mentioned newly galvanised chain does not stack well - it needs to be used and 'polished' and as implied, obliquely, Cromox is the way to go (and you could downsize as its G60, not G30) - if you have a winning lottery ticket The other advantage of Cromox, apart from invoking envy, is that it is retrieved a bit cleaner in muddy anchorages.

Most chain lockers are simply the space left over after the accomodation is designed - and are an afterthought. Most of us have little opportunity to alter the design and the best you can do is add a grating at the bottom to ensure the chain does not sit in a puddle of water. To get a decent locker you need to move the windlass aft - and that then inevitably will impinge on the forepeak.

Ideally the locker needs to be both deep and wide/broad - allowing room to store any rope portion of the riode in the locker - but separate from the chain (hanging so as to dry)

https://www.sailmagazine.com/diy/know-how-ground-tackle

Jonathan

 

[NormanS]

To say that the chain locker needs to be "both deep and wide/broad" is a bit of a cop out.
Our forepeak locker has a raised deck, giving extra volume, and has access from two deck hatches, one to port, and one to starboard. I fitted a fore and aft bulkhead (made from a bit of plastic fishbox), so the chain is all kept to starboard, leaving the port compartment for all the other associated stuff. Thus we actually reduced the available space for chain, but there is still sufficient, even if it means that my wife sometimes has to put her (booted) foot in, and coup the pile of chain, once the anchor is nearly home.

 

[Neeves]

To say that the chain locker needs to be "both deep and wide/broad" is a bit of a cop out.
.

Accepted.

If its deep and narrow and rope is at the bottom - then the chain always sits on wet rope. Your idea is very sensible - but can only be achieved if the locker is deep and wide/broad and you make it skinny and narrow by adding a divider - and you end up with 2 deep and narrow lockers.

Based on the idea that chain, or anchor, lockers are an afterthought and simply use the space left over after the accomodation has been 'designed' then few will be able to divide the parsimonious offering into 2. An alternative is a means to hang the rope as high up as possible.

Jonathan

 

[vyv_cox]

Barry Neilson, owner of Sailing Holidays, wrote an article on the subject, in YM a couple of years ago. Some of his boats have chain lockers extended downwards, a modification carried out by themselves, to avoid the need for inexperienced punters to shift chain when anchoring, a potentially hazardous operation.

 

[NormanS]

Barry Neilson, owner of Sailing Holidays, wrote an article on the subject, in YM a couple of years ago. Some of his boats have chain lockers extended downwards, a modification carried out by themselves, to avoid the need for inexperienced punters to shift chain when anchoring, a potentially hazardous operation.

Visions of a "blister" extending out of the hull.

 

[vyv_cox]

Visions of a "blister" extending out of the hull.

Maybe combine it with a forward extension as with ships?

 

[GHA]

So what rectangular footprint works with 10mm chain anyone?

Tia

 

[Neeves]

I interpret you are considering changing your existing bow locker (or the locker that holds the chain) so as to better accept what you have.

This suggests you are considering some serious improvements.

An alternative is to think of 8mm G70 (or an 8mm G100 and subsequently galvanised) chain which will take up less room than the 10mm chain (which presumably would be or will be G30 or G40). You would need a new gypsy (as you would be singularly lucky to find an 8mm spare lying around) but this might be simpler than attacking the existing structure with an angle grinder and any subsequent remedial work.

I think I recall you use sensible snubber(s) and have oversized anchor(s) - you seem good to go (or at least good to consider).

Jonathan

 

[NormanS]

So what rectangular footprint works with 10mm chain anyone?

Tia

Having just had my 62m of 10mm chain regalvanised, I can tell you that it fills approximately 300mm of a standard 40 gallon oil drum. You can calculate the volume from that, but chain dropping into a locker may not stow itself quite as carefully.

 

[Neeves]

Having just had my 62m of 10mm chain regalvanised, I can tell you that it fills approximately 300mm of a standard 40 gallon oil drum. You can calculate the volume from that, but chain dropping into a locker may not stow itself quite as carefully.

Actually once the exterior zinc has been worn off and the underlying alloys polished a bit on the seabed - it should pack a bit better - but then the windlass will drop it all into one place - unless Norman you are willing to pack GHA's rode, carefully, every time he uses it.

Jonathan