"Roger Long" wrote in message
...
I would certainly agree with 10 years in salt water although very
few people actually do. I can't remember seeing or hearing of a
dismasted coastal cruiser.

Any Great Lakes or other fresh water owners have recommendations
or dismastings to report?

--

Roger Long

Not answering your question - but attempting to put another
dimension into the discussion -

Most failures on properly designed rigs are due to metal fatigue
(agreed, often initiated by tiny corrosion weaknesses). So surely
the prudent timing of rig replacement will depend on the degree to
which the rig is over-designed? A point often ignored by insurers.

A European example which I know of is the difference between a
40ft Oyster and a 40ft Beneteau, both built around 1990, with
nearly identical masts. All the Oyster's main rigging was 10mm,
with intermediates of 8mm. The Beneteau used 8mm with 6mm
intermediates. The Oyster was advertised as a 'round the worlder',
the other as a 'performance cruiser'. My (unthinking) reaction
would be to life the Beneteau rigging at around 10 years, and give
the Oyster nearly twice that.

But then the mean streak in me came out. Instead I instituted a
regime of annual *close* inspection (most of the suitable
techniques have been aired already). Bottlescrew crack? See if
there's an obvious cause of the fault; if you can't find a cause,
replace them all. Strand gone? Search for obvious causes; if none,
replace all similarly stressed wires.

Under this regime all the Beneteau rigging was replaced between 8
and 12 years old (inner forestay twice). Most replacements were
initiated by strand failures at the bottom swage. The Oyster
changed a forestay at 10 years (yard damage bent the stay when the
mast was lowered, cracking a strand at the upper swage) and the
backstay sustained damage on a yacht lift. The inner forestay was
replaced twice - cracks at the lower swage. All bottlescrews
replaced. 25 years so far for caps and intermediates . . . I think
the new owner is replacing these for long term peace of mind!

I'm aware that the Oyster was about twice the displacement of the
Beneteau, so the inertia stresses on the Beneteau rigging would
have been higher (all that bouncing around!). So perhaps my
assumption about overdesign has been amplified in this case.

Whatever, my conclusions a

1. Nothing beats annual *close* inspection for checking rig safety
2. Corrosion initiates many failures (bottom swage faults most
common)
3. Your chances of suffering a fault are much higher on more
highly stressed rigs
4. The 'life' of a rig can be very long indeed if it is
understressed (under-use or overdesign)

So, thinking about all the rain we have in W Europe, my opinion
(untested) is that the fresh water issue is probably secondary
compared to the design issue.

JimB