Does Size really Matter?

[Sailorbob8599]

Ok, I know what some of you are thinking ... but my question pertains to the ID of a Deck Pipe for the anchor chain.

I'm installing a 'manual' MUIR Neptune windlass with a gypsy for 1/4" BBB Chain.

I need a simple Deck Pipe eg: Straight pipe with a deck-mount flange. I've purchased a couple of types from the Chandler but, they're not exactly what I'm looking for. Therefor, it appears my only option is to get one made at the local machine shop.

Now, I know there's a formula for determining the ID ... It is a multiple of the chain size. But what that multiple is temporarily escapes me. Would any of you long time sailor's have the number for me? Thanks .....

[GordMay]

Acco (Peerless) 1/4" (nominal) Hot Galvanized "BBB" Chain is actually manufactured from 9/32" wire (0.281"), and has a nominal inside width of 0.43".

Hence, the total width of chain would be [(.281 + (2 x .43)] about 1.141" - which should represent the approximate absolute minimum I.D. for a deck pipe.

You’ll actually want to be slightly larger, to allow easy passage.

Don't forget to measure your chain to rope connection, if fitted.

See also:
Welded Steel Chain Specifications:
http://www.nacm.info/Downloads/NACM%20_Welded_Specs.pdf