[Rhodes22-list] Engineering Idea

[Arthur H. Czerwonky]

Slim,
I have found a solution on my boat for the mast crutch crunch - a tube with a fork on the top and a fork on the bottom, made steady with lines tied to the stern rail.
Art

-----Original Message-----
>From: Slim <salm at mn.rr.com>
>Sent: Sep 3, 2005 11:12 PM
>To: Rhodes <rhodes22-list at rhodes22.org>
>Subject: Re: [Rhodes22-list] Engineering Idea
>
>Thanks Todd and you're right--this is not my idea.  As I was raising my mast
>to launch in the Apostle Islands, a gentleman watching me told me of a
>couple other boats that use the boom for a gin pole.  I like the idea of
>parts doing double duty and wondered if we might dispense with at least one
>big part--the GB crane.  I'd rather not sail around with it on board, trying
>to find a place to stow it.  Our boat is already loaded up with stuff.
>
>I lower the mast to the stern.  But whether I use crane or boom, what about
>the quick-release levers on the forward lowers?  If I also got the mast bail
>(which I've just ordered) I wouldn't have to mess with disconnecting and
>reconnecting ANY shrouds!  That alone would save a lot of time and fuss.
>There are a couple examples in the WM catalogue pg. 1022 but the throw is
>only an inch or two.  If I could get an 8" throw, I could eliminate two more
>parts--the two extensions.
>
>I'd worry about lowering the mast without a crutch, letting it hang there
>while we motor under the bridge.  When it's down in that position, that's
>when there's the most stress put on everything.  And you'd be sitting in the
>cockpit at the helm if it failed--not good.  However, using the boom as a
>gin pole, its greater length would mean greater leverage and therefore less
>stress on everything.
>
>But thanks for the ideas and the drawings.  I like the cockpit table socket
>idea.
>
>Slim
>
>On 9/3/05 6:58 PM, "Todd Tavares" <sprocket80 at mail.com> wrote:
>
>> Slim,
>> 
>> I think Macgregor has done something like this already. It seems like
>> they saw GB's mast raising system and copied it.   I didn't study your
>> e-mail in great detail, but are you planning to lower the mast toward the
>> bow? Why do all of the extra engineering when you already have a mast
>> crane?  Maybe you could make a two piece or folding temporary mast
>> crutch.  Make a single pole temporary crutch that would, say fit into a
>> wooden block dropped into the cockpit table socket. Or a double pole
>> crutch that could be spread and set down on the cockpit seats?
>> 
>> Set your crane up like normal.   Disconnect the furler/headstay. Connect
>> the crane to the foredeck and mast using the stays or a bail on the mast.
>> (maybe attach your spreader link thingies?)  Lower the mast unto your
>> temporary crutch and motor like heck under the bridge.   You may even get
>> away with just lowering the mast and stop it where you need it.  I do not
>> know how the GB crane winch works, but can't you stop where ever you want
>> and ahve the winch brake hold the mast?  If so, you could have your first
>> mate steady the mast, set the brake, and you could go aft to hold the
>> mast while she motors under the bridge?
>> 
>> You would have to do the math to see how far to lower the mast to clear
>> the bridge at the highest water mark.   Make the crutch to the correct
>> length, and find its best position/ location.
>> 
>> For ideas, see:  http://www.boats4sail.info/mast.html and attached
>> drawings.  Sorry for the crude drawings, but I didn't have a lot of time
>> to draw them.
>> 
>> Todd
>> 
>> 
>> 
>> ----- Original Message -----
>> From: Slim
>> To: Rhodes
>> Subject: [Rhodes22-list] Engineering Idea
>> Date: Sat, 03 Sep 2005 15:30:18 -0500
>> 
>>> 
>>> 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
>>> 
>>> __________________________________________________
>>> Use Rhodes22-list at rhodes22.org, Help? www.rhodes22.org/list
>
>__________________________________________________
>Use Rhodes22-list at rhodes22.org, Help? www.rhodes22.org/list