6mm or 8mm

[Yachty98]

Hi all

Currently got 28m of 8mm grade 30 with 50m 14mm 3 strand on a 26ft 3T westerly yacht, having problems with the chain pipe and chain piling up and also the chain jamming in the bow roller against the forestay pin. Also the weight of recovery with a 10kg anchor.

My question is could i go from 8mm G3 to 6mm grade 3?

[Yellow bird]

For a 26ft 3Ton boat a chain of 6mm is is more than enough,
but better a G4 standard, and 35/40m of chain IMHO

[Ibetitsthisway]

there are tables to check the windforce on a certain boat at certain windspeeds.

Ausgeübte Zugkraft je nach Windstärke und Bootslänge

Bootslänge
15 knoten
(4 Beaufort)
30 Knoten
(7 Beaufort)
42 Knoten
(9 Beaufort)
60 Knoten
(11 Beaufort)
120 Knoten
(Orkan)
4,50 m 25 kg 100 kg 220 kg 450 kg 1800 kg
6 m 40 kg 160 kg 320 kg 650 kg 2600 kg
7,50 m 55 kg 220 kg 440 kg 880 kg 3550 kg
9 m 80 kg 300 kg 620 kg 1260 kg 5080 kg
10,50 m 100 kg 400 kg 800 kg 1630 kg 6540 kg
12 m 130 kg 540 kg 100 kg 2180 kg 8720 kg
15 m 180 kg 710 kg 1450 kg 2900 kg 11620 kg
18 m 220 kg 900 kg 1800kg 3620 kg 14530 kg
21 m 300 kg 1200 kg 2450kg 4850 kg 19620

so - decide on which weather you will anchor in and check the .. i dont know the english word ... maximum force your chain can cope with. any serious shop will give you the data.

greetings ralph

sorry for the table format - first column is the boat length... it should be available on english websites too

it becomes obvious that if you have a 12-15m boat and want to be safe for even 120kn gusts in remote areas, this will result in very heavy chains, or very expensive material.


for your boat bf 9 means about 500kg force - not problem with a 6mm chain.