mooring lines longevity

[Ken Heyman]

We are on a can approx. 5 months every season. When not on the can (day sailing or cruising) the lines are partially in the water. I have two lines running, from a shackle attached to the can, through the anchor rollers (on either side of the forestay) and then being affixed to a single cleat on deck via good professionally spliced loops  . The lines are "thimbled' and attached to the mooring can via a shackle. Accordingly there is little chafing and no metal to rope contact other than the thimbles. This is the seventh season for these particular lines. Since we bet "all the marbles" on the lines doing their job I wonder if they should be routinely replaced. The lines are 1/2 inch(or maybe 3/4) three strand. The loads are normally relatively modest as our harbor is well protected from surge although we do get an occasional micro-burst that can produce brief heavy winds (two years ago measured at 80 mph!)I haven't done much to maintain them although they look good upon inspection. I was considering cleaning them but felt my wife might object to the shackles totally destroying our washer and dryer. I wonder if there could be insidious non apparent damage. Any thoughts?

Ken

[Footloose]

Ken,

FWIW:  We have a similar situation.  I use 5/8" line and I replace my mooring line every three years.  By then it has gotten stiff and I don't trust it.  I figure it is cheap insurance. 

[Ron Hill]

Ken : Not too sure about the "age limit", but I'd guess that with your shortened season in the Chicago area you should be able to get about 5 years about of them.
Now on the type - Boat US had an interesting article that basically said that 3 strand will wear better than braid on braid !!  It seems that braid jacket and the core stretch at differant coefficients.  This differance causes heat and hence wear !! 
I'd use 5/8" for the size.  A thought