Anchor chain marking - Base 3 numbering

  • Thread starter Thread starter Anonymous
  • Start date Start date
[ QUOTE ]
Pass another Pinkers ol-bean ...

[/ QUOTE ]
Thanks for the input, which is what I was hoping for.

Ideally, of course, we would have a chain counter (especially an integral one!) but that is not affordable or practicable for us.

There are just two of us on board - like thousands of cruising couples or families - and I don't let my wife anywhere near the ground tackle. It is too heavy and dangerous for her and there is no need so I don't need a system that is intuitive for others.
anchor_controller.jpg

We anchor every day from May to September, very often in crowded or very constrained anchorages. Although markings every 5m might seem too fine to those of you who anchor occasionally and seldom in a very crowded anchorage, a few metres can make a big difference in the Med. Quite often in one wind direction you have to keep the rode very short but when the wind is in another direction you have more room. You seldom leave the chain length fixed if you are staying for a while, in a very crowded anchorage. When the weather is fine, you can often bring the scope down to 3:1, with a good bottom, but if the wind picks up you might need to increase that to 6:1 or much more. Suppose you are in 2m water, 2m freeboard, i.e. 4m 'depth', then 3:1 requires 12m chain and 6:1 requires 24m chain. Remember, a typical yacht is about 12m and we are often anchoring one boat length away. Frequently, others anchor to within a few metres or so then (hopefully) move on but not before we have had to pay out more chain to give clearance. So, you see, we are often changing the length of chain every day or several times a day, and we have to put out the minimum safe amount. The only way to calculate the minimum safe amount is on paper - find the depth, and make allowances for the bottom and the weather. It's not a 'seat of the pants' sort of calculation, it is quite deliberate and having made the decision to pay out, say, 18m, it would be nice to actually have 18m out there! As soon as you start paying out and bringing in chain on a regular basis you quickly lose track of where you are....you need a marking system that unequivocally states the length out there but you seldom (if ever) need to have that information instantly.

As for being 'intuitive', other than a chain counter, I don't know of any really intuitive system. I will print a card (photograph) which I will make up with Photoshop, which I will laminate and hang from the same necklace chain that the controller will hang from (see photo). There will be a diagram showing which way to read the colours, which will be as unambiguous as I am able (there will be a diagram on the rear side). It think that these colours, red, yellow and green, will be fine. We have a deck light and I always wear a head-lamp on deck at night, anyway.

As for base 3 vs base 2, or any other numbering system, if you look at the most significant digit, that gives a first order indication of depth. Have a look at the pattern and you will see that it is not as un-user-friendly as you would imagine. Similarly, the next most significant digit. Base 2 would require too many coloured bits; that would make it harder to read, and they are expensive! Base 10 would be ideal, using the resistor colour code, but I have found (and been told by others who have had the same experience) that after a short while paint becomes very hard to discriminate; you can always see that the area has been painted, but it becomes hard to determine between colours. I haven't found a source of anchor markers in the required colours for the resistor code - maybe there is a market opportunity for the manufacturers.

Many thanks for your thoughts, I appreciate the feedback, and please keep them coming in as I shall not make the final decision until the weekend.
 
If it's any reassurance, I also find the little coloured rubber chain markers good and have used them for a number of years, loosing very few. I also have my chain marked every 5 metres and do find 5m and 10m marks useful: on lifting the anchor they make it much easier to judge when it leaves the bottom, which is usually considered an event of some interest.

I must agree with others, though, that a base 3 system, while ingenious, does have drawbacks - particularly the need to remember which end of the colour sequence is the most significant. FWIW I use a system of symmetrical markings where each 10m is given a solid colour: red, yellow, green or blue with the 5m marks white between the "next colour up", i.e. RWR etc. I keep a sticker with the coding stuck on the underside of the anchor locker lid.

I do, however, only have 40m of chain and, given the limited range of available colours for the rubber inserts, am not sure how I would mark a longer one!
 
Sorry if the "intuitive" word causes problems. In my work I assume that the instructions to restore a particular process are going to be read by someone who has never read the manual before. Anc hor marks must be not be capable of misinterpretation; e.g. are they from the anchor end or from the bitter end ? Meters, yards or fathoms ?

Any system has to be "transportable" to the boat's other chains, so that if you swap a chain, or add one to another, you can get a pretty accurate (say to 2.5m accuracy) knowledge of the length beyond the bow.

I mark in etching paint in thick bands for each 10 m, with "blob" every intermediate 5 m. The paint doesn't wear off very easily, and as the chain goes out of the hawse you can see, say 4 big bands, and you know the next mark will be 45 m FROM THE ANCHOR.

Etching primer spray
http://www.duplicolor.com/products/primer.html


Each of the three chains we carry has a different colour, so if we ever had to join a couple, the foredeck gorilla calls out "Yellow 25" which you know is the add-on to the White chain - which is 60 m.

The windlass has a schematic of the marks, so that a new crew member can see what the codes and colours represent. It's part of the standard safety briefing. (The marks are made using Edding permanent markers as used in the aircraft industry. They do NOT wear off either steel or plastic.)


Aircraft permanent markers
http://www.edding.com/105_DEU_HTML.htm
 
Thanks for your input. I've only found red, green and yellow markers locally (made by Osculati). With more colours I would certainly re-visit the coding. I could easily postpone this project if I could obtain more colours by mail order but I haven't found any.

Meanwhile, knowing whether to read from one end or another isn't a major problem, I think, as I will make the card up in Photoshop with a small picture of the windlass and chain and a superimposed example, showing the user how to read the code. The code will start (MSD) at the windlass with the LSD nearest the bow roller. Since that's how you would always look at the assembly, it should be intuitive.

I agree with you re the last few metres. The other occasion is when the anchor gets fouled while bringing it up. You are on the foredeck, with a very short rode, causing terrible snatching, not knowing whether you are just jammed in a rock or something just under you or whether you have gone a couple of times round a piece or (uncharted) wreck which once happened to me. It will be nice to know the exact length of chain out!
 
Yes, mine are made by Osculati too and they definately do (or at least did) make them in blue and white as well as red, yellow and green, but I think that's it. (No black, brown, orange etc. so like others I used basically the resistor colour code but offset a bit...)
They also had a free code sticker in some of the bags.
 
Exactly. Keep it simple.

We are often anchoring in very crowded anchorages with lots of comings and goings. In the comparitively shallow waters we frequently have to use (between 8 and 12 feet) it is very important to get it right.

I just feel this 3 base system seems uneccesarily complex.

We find the self am tape does us for about three years. It also shows up well in night lighting
 
Like most others, I would suggest you reconsider.

I have used the plastic markers for years, but in low light conditions it is surprisingly hard to tell the difference between certain colours when they get a bit dirty (blue and green for example). And when the chain is whizzing out it will be almost impossible to discriminate.

I mark every 5 metres (yes, you don't ever want to put 5 metres out but you do want to know when the first five is out and the last five is back). I do this in blocks of colour i.e. 5 green, 5 red, 5 blue, 5 yellow. This covers 20 metres then I start over again. It's easy to explain and if you miss one it's not a problem. I put a sign with big letters on the anchor locker lid for newbies.

I've never lost a plastic insert, but I do find it's good to give them a scrub every six months or so depending on where one is anchoring.
 
[ QUOTE ]

There are just two of us on board - like thousands of cruising couples or families - and I don't let my wife anywhere near the ground tackle. It is too heavy and dangerous for her and there is no need so I don't need a system that is intuitive for others.


[/ QUOTE ]

That puts a different slant on things. If you are happy with it, it's the right system.
 
[ QUOTE ]
See above M'Dear.
Gosh. I wish people would read bio's before casting cistercians /forums/images/graemlins/laugh.gif

[/ QUOTE ]Fair point - and I have sailed in US waters with Admiralty Charts (in metres) and US charts in feet. Should have read your bio first tho'...
 
[ QUOTE ]
No offense, but you are like my friend (exactly the same age as me ie 50) who insists on his echo sounder being in feet even though the chart and all the tidal data is in metres. Each to their own.


[/ QUOTE ]

I'm with your friend! Our echosounder too is set to read feet but then so are our chart plotters. The chain however is marked in metres, that way as a starting point on arrival we put out as many metres of chain as the depth expected at HW is in feet, that gives 3xdepth with 10% extra for luck, after that I'll probably readjust the amount as I feel needed, usually let out more, then add the snubber and relax.

I work with small dimensions all the time and only work in metric since the early '70s, but above say 150mm I find harder to picture and no way can I visualise the difference between say 1.83m and 1.98m whereas the difference between 6' and 6'6" is easy!

As for chain marking, we have coloured shockcords through the links and fixed with small cable ties, these are available as prepacked swindlery kits but are easy enough to make up DIY and very cheap, they run over the windlass gypsy easily. I can't remember the marking code as we inherited this one but I don't have to remember it as it is written on the underside of the anchor locker lid.
 
Slightly modifying OleWill's suggestion, you could use 2 of the colours to mark off 10 metre intervals in a base-2 system and then use the third as 5m halfway markers.
This would use about half the number of inserts (so its cheaper) but it does run out at 40m so if you restart it, you would need to remember whether you have 10m or 50m out there.
 
[ QUOTE ]
Slightly modifying OleWill's suggestion, you could use 2 of the colours to mark off 10 metre intervals in a base-2 system and then use the third as 5m halfway markers.
This would use about half the number of inserts (so its cheaper) but it does run out at 40m so if you restart it, you would need to remember whether you have 10m or 50m out there.

[/ QUOTE ]I don't want to live with markers 10m apart as much of the time I will not be able to see a determinate mark. I am prepared to pay the extra to have a determinate mark every five metres.

With a base 2 system at 10m spacing using two digits you'd run out at 2**1 + 2**0 = 2+1 = 3 i.e. 30m, not 40m.
 
[ QUOTE ]
With a base 2 system at 10m spacing using two digits you'd run out at 2**1 + 2**0 = 2+1 = 3 i.e. 30m, not 40m.

[/ QUOTE ]

My maths is a bit shaky, but this seemed wrong because no-one is talking about starting the marking at zero chain, so I did it long hand:

10 white white
20 white black
30 black white
40 black black

Have I got this wrong?

Mark
 
No, you are perfectly correct in that sense - I was thinking in terms of longer chains in which case you cannot dismiss the zero.
 
You are kind of both right. I was thinking of starting at 0m just to simplify the calculation but as you wouldnt actually mark it off you are free to use the 00 as the 40m mark.

Lemain, if you want a determinate marking at the 5m interval, you can simply repeat the previous marking but append the 5m mark. This would have the added benefit of giving a categorical reminder of which way to read the numbers as one colour would never appear anywhere other than as last digit.

so the system would go:

00.5 = 5m
01 = 10m
01.5 = 15m
10 = 20m
10.5 = 25m
....>
11.5 = 35m
00 = 40m

This system should be much easier to memorize than the base 3 system. As i said previously, the only catch I can see is the need to double up to get to 80m
 
[ QUOTE ]

so the system would go:

00.5 = 5m
01 = 10m
01.5 = 15m
10 = 20m
10.5 = 25m
....>
11.5 = 35m
00 = 40m

This system should be much easier to memorize than the base 3 system. As i said previously, the only catch I can see is the need to double up to get to 80m

[/ QUOTE ]
This is looking promising, thanks. If I make the third band (the 5m band) yellow throughout the first 40m and red throughout the second 40m the marking is totally determinate and, as you say, easier as one does binary in one's head and anyone can multiply by 10. Unless anyone can come up with a better scheme, that's the one I'll go for. Many, many thanks!
 
You must log in or register to reply here.

Share this page

Top