powercat anchor chain size

[tenniscaptain]

Keeping in mind I want to keep weight within reason, I am considering chain size
for my primary anchor rode. Powercat is 67' weight 50 tons. Original plans call for 3/8 BBB chain of 300.' Opinions on whether 3/8 is sufficient or 1/2 would be necessary?

 

[dimer2]

TC, there are now stronger chains, namely G43 and G70, out there. This may let you go down a size. I am not an advocate of an all chain rode but everyone has their preferences. There are plenty of websites that will advise you on size, windage etc needs to be taken into account.

 

[Xsbank]

I'd go with 1/2" on a 50-tonner. I am planning 5/16" high test for my 50 footer, 29 tons, because I can't get 100' on my drum with 200' of 3/4".

 

[Xsbank]

Acco G4 1/2" has a working load of 9200# and weights 257# per 100#, which is only 50# more than 7/16" and no problem for a 67 footer. Good combination of weight and breaking strength.

 

[tenniscaptain]

Great information. Thanks very much.

 

[FF]

Usually the windage , even on a Cat, is not the problem with anchor loads..

Its either the surge from waves in the harbor , or more common the load as the boat veers in the windy consitions.

If the boat is docile at anchor it is a big help, other wise a bridal will need to be rigged to keep the dodging to and fro to a minimum.

A heavy weight a cast iron lump underfoot can dampen the dodging and ease the anchor load.

I would go for the 1/2 inch for overnight , and switch to stronger nylon in a blow.

Even fairly thick chain is not that strong.

 

[Xsbank]

Isn't working load on a chain 1/4 of its breaking load? 9200 pound working load is 36,800 breaking point? I'm a little rusty on this (intended) but I think you'd have to have at least 1" and probably larger rope to beat that chain.

 

[Xsbank]

In fact Wiki says 1/5th for lifting loads and high tensile could be considered lifting. How's 46,000 pounds?

 

[Xsbank]

Read the Samson rope catalogue for a definition of rope breaking strength and working load.

 

[dimer2]

This chart only goes to 50,000 lb and shows a 9/16 " chain.

BOAT SIZE ANCHOR RODE
Length (ft) Weight (lbs) Chain (dia.-inch) Nylon (dia.-inch) Length (ft)

20-25 2,500 3/16 7/16 90
26-30 5,000 1/4 7/16 135
31-35 10,000 5/16 1/2 190
36-40 15,000 3/8 9/16 225
41-45 20,000 7/16 5/8 240
46-50 30,000 1/2 11/16 315
51-60 50,000 9/16 3/4 360