Author Topic: Cruising chute stemhead fitting  (Read 8083 times)

symphony2

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  • Boat Model: B33
  • Boat Year: 2015
Re: Cruising chute stemhead fitting
« Reply #25 on: May 20 2021, 13:31 »
First photo shows the standard arrangement for the strut that runs from the crossbar to the stemhead. (not my boat but exactly the same arrangement). It is bolted to the stemhead tang and is in 2 parts, the upper part which is welded to the crossbar, sliding into the lower and locked by a bolt. This enables the pulpit to be adjusted as i guess they are not all identical.

Second photo shows the crossbar with the platform removed. I cut the strut off here with an angle grinder then Dremel. Horrible job because of the angle and the amount of weld! Brackets were welded either side for the legs of the U bolt and then the two parts of the strut welded together to achieve exactly the right height between the lower tang and the crossbar. This means the spinnaker loads are taken direct to the stemhead tang.

The other 2 photos show the final product. Works OK , but a bit close to the forestay when used with the top down furler. My biggest concern was whether the pulpit and strut would be strong enough to take the loads, bit think my solution is OTT and might have been easier to have a stainless plate with a U welded on with 4 bolts going through the platform and saddles underneath around the crossbar. The locking bolt for the sliding part of the tube could then be replaced with a through bolt rather than welding the 2 together.

Hope this is of interest.

MagicalArmchair

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  • Boat Model: Bavaria
  • Boat Year: 2002
Re: Cruising chute stemhead fitting
« Reply #26 on: May 20 2021, 16:57 »
Thanks Symphony, I like the option of plate on top with saddles underneath.

Geoff, Rampage, do you have any photos of your set ups? I'm down at the boat at the weekend... might sneak down at lunch tomorrow too so I'll play around with a few options.

I'm away for a week on her in a week, so if the conditions are right I want to be able to fly the sail, and it will only be flown in light airs to start with.

MagicalArmchair

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Re: Cruising chute stemhead fitting
« Reply #27 on: January 22 2022, 15:11 »
I'm still contemplating this one.  ::) One of these looks particularly interesting.

https://www.oceanchandlery.com/oleu-tack-collar-large.html

Cheaper than the ATN, and it'll still have the same drawback of struggling dead downwind, but then, that is a pretty hateful course to be steering anyway. Has anyone got any experience of these? It seems like a nice simple way to fly the chute.

elias

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  • Boat Model: Bavaria 44
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Re: Cruising chute stemhead fitting
« Reply #28 on: January 22 2022, 19:10 »
I went through the same problem for hoisting an asymmetrical on a top down system but finally I made a retractable bowsprit  . I used Selden’s calculators for Righiting moments when healing . For your BV33 must be around 23KNm and the maximum force on your tack theoretically around 4,4 KN ( 400kg for simplicity ) .

To test it I did the following . I used a new thin rope of 1m of breaking strength 300kg , attached from the tack of the bowsprit fitting to the halyard ,I charged it slowly with the winch until break to see any deflections.