[Rhodes22-list] Engineering Idea

[ed kroposki]

Slim:
	You have too much time to think lately.  I thing you are trying to
reinvent the wheel.  The General Boats mast hoist can be used for exactly
what you are trying to do.  I have seen a picture of R22 doing exactly what
you want to do.  I do not think that he had the mast support during the
transit under the bridge. 
	Go measure the distance between the water, the lowered mast and the
bridge.  
	Now that you have all this time, when are you coming south?

Ed K
Greenville, SC, USA
Addendum: "If you put the federal government in charge of the Sahara Desert,
in 5 years there'd be a shortage of sand", Milton Friedman 

-----Original Message-----
From: rhodes22-list-bounces at rhodes22.org
[mailto:rhodes22-list-bounces at rhodes22.org] On Behalf Of Slim
Sent: Saturday, September 03, 2005 4:30 PM
To: Rhodes
Subject: [Rhodes22-list] Engineering Idea

Lake Minnetonka, my home waters, is divided into two parts separated by a
bridge.  If I could get under the bridge, it would more than double the area
in which to sail.  I'm thinking of a way to drop the mast quickly to get
under the bridge.  I'm no engineer so I'm way out of my league here but what
about this:

Eliminate the GB hoist crane and use the boom for the gin pole.  Replace the
big GB mast crutch with a single pole.  Eliminate the 8" shroud extensions
and replace with lever-operated quick release mechanism like some boats have
on running back stays and some boats have levers on the upper
shrouds--slacking one depending on the tack.

I'm imagining this procedure to take less than five minutes:

1. Slack the back stay tensioning line.

2. Disconnect the main sheet from the boom.  (No need to remove the traveler
bar.)

3. Deploy mast crutch. (Single telescoping pole with  "V" on top.)

4. Disconnect boom at gooseneck and walk the boom forward.  (The two lines
going to the aft end of the boom, the topping lift and the main sail
outhaul, stay connected and simply go slack when the aft end of the boom is
at the foot of the mast.)

5. Secure the aft end of the boom at or near the foot of the mast.

6. Disconnect bow stay and insert block and tackle between bow stay and the
chain plate.  (The forward lowers are holding up the mast.)

7.  Connect forward end of boom to the end of the bow stay/block and tackle
connection.

8. Throw off quick-release levers on forward lowers.

9. Lower the mast.

I know the devil's in the details--how to connect the aft end of boom to, or
near the foot of the mast and how to connect the forward end of the boom to
the bow stay.  The GB hoist winch won't spin if you let go of it whereas a
block and tackle would run if you let go.  (So don't frickin' let go!)  It
could have a cam cleat so you could set it and walk away.  The boom is a lot
longer than the GB crane pole and would provide greater leverage but maybe
it's TOO long--I haven't measured--although where it hooks on to the bow
stay doesn't necessarily have to be at the very end of the boom.

I'm just brain storming here but is this feasible?

Slim

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