"Bruce in Bangkok" wrote:

Something I have always wondered about is that everyone talks about
anchors but nobody seems to talk about the anchor rode.

For example, 3/8" Grade 30 BBB galvanized chain has a working
strength
of 2,650 Lbs., 25% of its breaking strength of 10,600 Lbs. 5/8th
inch
double braid nylon rope has a tensile strength of 15,000 Lbs. and if
we go to Kevlar core double braid we are talking 22,000 Lbs.

If you are going to use nylon rode in combination with chain, then the
nylon serves as a spring, stretching with increased load.

Basic reason to select 3-strand nylon of modest size to allow for this
stretch.
..
Yes, I know - catenary..... but Alain Hylas (Inventor of the 'Spade'
anchor) say the opposite. He says that once the wind gets 20 - 30
knots (a gale force wind) the chain becomes effectively a straight
line, in other words for all practical purposes the catenary is gone
(Note: you can never pull the chain completely straight) and wave
shock is transmitted directly to the anchor.

So why do nearly all cruising yachts use an all chain rode? And, why
does everyone talk about anchors but ignore the "thing" that
attaches
the anchor to the boat?


That's why snubbers exist when using all chain rode.

A hank of 3-strand nylon with a chain hook in one end and the other
secured around the mast will accomplish this function.

Lew