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Maine Passage - Day 5

Wwhen you tighten the shrouds on a keel stepped mast, the chain plates
are pulling up thus caving in the sides of the boat. The cabin deck is
pinched up and the partner rides up the mast.
Now imaging lots of sail up in a rough sea, those shrouds are apumpin
and that cabin top is moving up and down causing all kinds of problems
down the line.
The fix is a tie rod running from the step to the partner with a
strenghtened cabin roof. Top can't ride up, sides can't cave.
Gordon

Maine Passage - Day 5

"Richard Casady" wrote

It isn't spelled tension.

It's spelled "Rigging wire tension".

--
Roger Long

Maine Passage - Day 5

On Mon, 04 Aug 2008 10:15:10 -0700, Gordon wrote:

The fix is a tie rod running from the step to the partner with a
strenghtened cabin roof. Top can't ride up, sides can't cave.

Yes, and the whole boat will be stiffer as a result, like a big box
beam.

Maine Passage - Day 5

In article , Wayne.B wrote:
On Mon, 04 Aug 2008 10:15:10 -0700, Gordon wrote:

The fix is a tie rod running from the step to the partner with a
strenghtened cabin roof. Top can't ride up, sides can't cave.

Yes, and the whole boat will be stiffer as a result, like a big box
beam.

Once the novice had been round and tightened his shrouds (which were loose on one tack, IIRC), I'm guessing this set-up would then retain that tension... but the whole lot would be under a lot more stress.

Just curious.

Justin.

--
Justin C, by the sea.

Maine Passage - Day 5

On Mon, 4 Aug 2008 13:22:48 -0400, "Roger Long"
wrote:

"Richard Casady" wrote

It isn't spelled tension.

It's spelled "Rigging wire tension".

Especially when you are discussing the mast?

Casady

Maine Passage - Day 5

Yes, the proper tensioning of the rigging wire is a bit more complex and
critical in a keel stepped mast than a deck stepped one. Everything can be
quite loose in a deck stepped mast and the mast will be perfectly well
supported since it will just rotate about its step. Insufficient tension in
a keel stepped mast can introduce a bend just above the deck/cabin top
partners. This bend can contribute to column instability.

In practice, there won't be significant difference in wire tension between
the two rig types but the deck stepped is more tolerant of under tensioning
of the wires as long as the tension relationship between the uppers and
lowers is right.

--
Roger Long

Maine Passage - Day 5

Bruce in Bangkok wrote:

I have a deck stepped mast but from what I read all keel stepped masts
will deform when the shrouds are tensioned. The usual fix if a "tie
rod" which is bolted to the deck and the mast step to prevent the deck
from flexing upward. Apparently this is a normal trait of keel stepped
boats

I disagree that the boat should flex enough that he can't get the sole
hatches open w/o a struggle. Any reasonable boat design needs to
consider the rig being in proper tension.

I understand the tie rod you mention and would think that an issue on a
boat like an O'Day but on a seagoing vessel?

So here you are in the Morgan showroom taking delivery of your new
Morgan XXX. The salesman tells you if you actually sail the thing, you
can either buy a tie rod because the boat is improperly designed or you
can forget opening any hatches below because the boat is improperly
designed.

Seems perfectly incredible to me - either scenario.

Maine Passage - Day 5

On Mon, 04 Aug 2008 17:26:36 -0600, Paul Cassel
wrote:

Bruce in Bangkok wrote:

I have a deck stepped mast but from what I read all keel stepped masts
will deform when the shrouds are tensioned. The usual fix if a "tie
rod" which is bolted to the deck and the mast step to prevent the deck
from flexing upward. Apparently this is a normal trait of keel stepped
boats

I disagree that the boat should flex enough that he can't get the sole
hatches open w/o a struggle. Any reasonable boat design needs to
consider the rig being in proper tension.

I understand the tie rod you mention and would think that an issue on a
boat like an O'Day but on a seagoing vessel?

So here you are in the Morgan showroom taking delivery of your new
Morgan XXX. The salesman tells you if you actually sail the thing, you
can either buy a tie rod because the boat is improperly designed or you
can forget opening any hatches below because the boat is improperly
designed.

Seems perfectly incredible to me - either scenario.

First of all, you appear to be combining several posts into one.
Specifically mine about tie rods and someone else about hatches.

You can imagine anything you wish, however, the Pardy's wrote about
the installation of a tie rod in their second boat and while I hate to
quote them as an authority about anything they have probably sailed
more miles then most. I have also seen tie rods installed in keel
stepped boat of all sizes, shapes and material so I assume that there
is a reason, just as there is a reason for some boats having tie rods
connecting the chain plates, to the keel (again in a keel stepped
boat).

Bruce-in-Bangkok
(correct Address is bpaige125atgmaildotcom)