A bit of fun from last week...enjoy...

https://www.youtube.com/watch?v=Z2Iz6Zqnlkw

--
Hobie 16 (3 formerly)
MacGregor 25 (formerly)
Chrysler Dagger 14 (formerly)
NACRA 5.0 (currently)
High Point, NC
--

Great video.
I agree with the spreaders getting hung up theory.

--
Sheet In!
Bob
_/)_____/)_/)____/)____/)_____/)/)__________/)__
Prindle 18-2 #244 "Wakizashi"
Prindle 16 #3690 "Pegasus" Sold (sigh)
AZ Multihull Fleet 42 member
(Way) Past Commodore of Prindle Fleet 14
Arizona, USA
--

Something was definitely hung up with the mast. The mast was counter-rotated before the bang and then swung into proper rotation after the bang. Whether that was a spreader, shroud, or something else isn’t clear in the video, but it was definitely related to the mast being counter-rotated and then letting go under load.

sm

Spreaders. Probably due to being over-rotated and under-downhauled.

Put lots more tension on that sail and you’ll find it faster and easier to control. Maybe recheck the tension in your diamond wires and shrouds too. Since they all work together.

I was out on the traps this weekend on a Miracle 20 and the trap rings suddenly seemed too high. I also felt a weird sensation in the rig as I leaned out and moved around. It felt “twitchy”.

Turns out my trap line was wrapped inside the spreader bars and I was rotating the mast like crazy every time I moved! Good thing it didn’t slip and drop me in the water. When it released, it made that same popping/twang sound you experienced.

Love your videos. Keep posting.

--
Prindle 18
96734
--

I can't see how a spreader arm would get tangled in a side stay ... (looks like) there is a lot of space


I know trap wires can get tangled around spreaders ... but you have none

I know rotator limiters can get fouled on booms - but you have neither (as far as i can see)

I know spreader arms can get tangled in overlapping jibs ... but mast spreaders in side-stays?


i guess i could be wrong and during your last tack if your stays are slack enough to have slop in them i guess they could touch a spreader ...

i would suggest another possibility is your shackle on top could have been fouled/twisted somehow and released the stored up energy when it finally popped into the right place



Edited by MN3 on May 22, 2019 - 10:47 AM.

I’m not terribly familiar with the NACRA 5.0, but my thought was that the spreader probably got hung up on the leech of the jib after a tack. If the jib was sheeted in hard and fast onto the new side before the boat completed the tack, I could see that happening. There probably isn’t a whole lot else that it would have likely hung up on that would have caused a counter-rotation. A twisted shackle probably would not cause counter-rotation.

sm

Quote

spreader probably got hung up on the leech of the jib after a tack.

agreed -

I have never seen the jib hang up on spreaders on a 5.7 or 5.0. The rollers at the end of the spreaders are very effective, & the jib doesn’t touch them to near the degree of say an H16. Holding that tension would tear the jib.
In very flaky winds, the boom less Nacra masts can bang around quite violently. What I have seen is one of the shackles from the shrouds get twisted or hooked on the forestay shackle. . It “holds” the mast from free rotation, but eventually under load pulls free. The mast then rotates, & you hear the bang, & witness the release of the mast.
Perhaps your rigging was loose?
If you trailer sail, it’s easy to forget tightening that last shroud after raising the mast. Have a look at your mast hound, tape around protruding ends of shackle pins.



Edited by Edchris177 on May 22, 2019 - 08:45 PM.

--
Hobie 18 Magnum
Dart 15
Mystere 6.0XL Sold Was a handful solo
Nacra 5.7
Nacra 5.0
Bombardier Invitation (Now officially DEAD)
Various other Dock cluttering WaterCrap
--

I know the 5.0 comes without a boom, but did you add one?

--
Dart 20
--

klozhald

Great video.
I agree with the spreaders getting hung up theory.

Thanks, I'll be taking a look at everything suggested.

--
Hobie 16 (3 formerly)
MacGregor 25 (formerly)
Chrysler Dagger 14 (formerly)
NACRA 5.0 (currently)
High Point, NC
--

nohuhu

Spreaders. Probably due to being over-rotated and under-downhauled.

Put lots more tension on that sail and you’ll find it faster and easier to control. Maybe recheck the tension in your diamond wires and shrouds too. Since they all work together.

At times more downhaul would be appropriate, but our puffs are so short and lake so small I usually try to find the best fit middle ground for daysailing with more attention to it while racing particularly on larger bodies of water where the benefits of more on the fly tuning can be realized.

I have re-checked the diamonds and they were as tight as they were when I left the beach. I check the tension in them before every sail.

nohuhu

Love your videos. Keep posting.

Thank you they're fun to make and share. Hopefully they inspire folks to give cat sailing a try and/or put a smile on someone's face.

--
Hobie 16 (3 formerly)
MacGregor 25 (formerly)
Chrysler Dagger 14 (formerly)
NACRA 5.0 (currently)
High Point, NC
--

Edchris177

I have never seen the jib hang up on spreaders on a 5.7 or 5.0. The rollers at the end of the spreaders are very effective, & the jib doesn’t touch them to near the degree of say an H16. Holding that tension would tear the jib.
In very flaky winds, the boom less Nacra masts can bang around quite violently. What I have seen is one of the shackles from the shrouds get twisted or hooked on the forestay shackle. . It “holds” the mast from free rotation, but eventually under load pulls free. The mast then rotates, & you hear the bang, & witness the release of the mast.
Perhaps your rigging was loose?
If you trailer sail, it’s easy to forget tightening that last shroud after raising the mast. Have a look at your mast hound, tape around protruding ends of shackle pins.

Thanks Ed. All good advise. I haven't had time yet to take the mast down and inspect everything forensically. I will post what I find.

Also big thanks to everyone else who responded with theories to be investigated.

--
Hobie 16 (3 formerly)
MacGregor 25 (formerly)
Chrysler Dagger 14 (formerly)
NACRA 5.0 (currently)
High Point, NC
--

Edchris177

What I have seen is one of the shackles from the shrouds get twisted or hooked on the forestay shackle. . It “holds” the mast from free rotation, but eventually under load pulls free. The mast then rotates, & you hear the bang, & witness the release of the mast.
Perhaps your rigging was loose?

leeboweffect, I think Ed nailed it. Look at the gentle curve in both your shrouds are at 2:29 in the video, and then look at the change after the event. Your mast is rotated, the windward stay tightens up and the leeward one is even more loose.

leeboweffect

I haven't had time yet to take the mast down

Being able to store your cat mast up is sweet. Think about a small pair of binoculars to check on things aloft before you leave shore. I use a set because the five thimbles on my mast hound shackle sometimes get tangled when I step the mast. I have considered waterproof ones to take with me sailing to better ID the other boats, but they are $$$.



Edited by klozhald on May 31, 2019 - 11:39 AM.

--
Sheet In!
Bob
_/)_____/)_/)____/)____/)_____/)/)__________/)__
Prindle 18-2 #244 "Wakizashi"
Prindle 16 #3690 "Pegasus" Sold (sigh)
AZ Multihull Fleet 42 member
(Way) Past Commodore of Prindle Fleet 14
Arizona, USA
--