Dismasted this past weekend.

[tlgibson97]

Break at the top half.



Break at bottom half.



Looks like it made a clean break. It's just thin walled tubing. The twisted portion off to the side was where the two pieces remained attached until they broke apart handling it.
All I can see that I dont like is where the threads of the bolt eat at the hole.

I never removed the spreaders or really touched them except to tighten them a little when I bought it. Who knows how much the PO wrenched on it. I transport it with the spreaders resting on the lifelines.

[kmclemore]

To me it looks like a work-hardening break. How tight were your stays?

[delevi]

Sorry to hear about your mast breaking. First I heard of this on a Mac. First, be thankful that nobody got hurt. Also, want to echo the comments of most who responded. You did not push the boat too hard per your description. Assuming a properly tuned rig and undamaged mast, it should take much more than most skippers before anything breaks. When I had my I sailed in gale force conditions regularly. There are two likely reasons for what happened. The bend you describe was probably a weak point and may have had a shear and/or crack that wasn't visible. These masts bend but should not have any permanent bends. This is clearly a red flag. The other possibility is improper rigging. Even though the rigging survived while the mast broke, the mast may have broken because it didn't get proper support from the rigging, typically if it was too loose or severely unbalanced loads on one side. This may be covered by your insurance, so worth exploring. Best of luck.

Leon
Akula SF C380
formerly Mac

[Sumner]

How do you tension the rig when you put the mast up? I couldn't tell, do you run a furler or hank-on?

When you re-rig the boat I'd for sure invest in a loos gauge and get some figures on shroud and forestay tension and ask other X owners what theirs are. The upper shrouds should tension the forestay and the lowers should mainly make the mast straight from where the uppers attach down to the deck.

If I was guessing and this would be just a guess, the lowers were probably tight and the uppers loose and the mast over time was pumping side to side with possibly the previous owner and then maybe you also. Then the mast finally fatigued at the point of the lowers since it was bending there. Just a guess but you should be able to sail the boat in about any conditions without worrying about the mast breaking,

Sum

===================================
Our MacGregor 26-S

Our Endeavour 37

Our Trips to Utah, Idaho, Canada, Florida

Mac-Venture Links

[kevinnem]

I had 2 things I that popped in to my head.

1) I find it odd that the mast breaks at the top - is this typical??? the sail area is triangular - and gets smaller at top - and as such the forces should get small at the top as well.

2) is it possible that the speaders themselfs "pinched" the mast, deforming it and causeing a weak spot?

is there a torque/moment situation that caused this maybe?

Out of curiosity , when it broke did it break "left/right" or "fore/aft"?

Kev.

[DaveB]

The MacX in early stage came with a fixed spreader, there have been mods on this board to change to a swing arm spreader attachment.
I would look at this if the PO made the change and how he did it. Spreaders on mast is a weak point and any changes could weaken the stress point.
When sailing heeling over to windward, did you notice slack of stays at leeward side?
If rigging is tensioned proper even a strong acidential jibb would not cause a break at the spreaders.
Something here just doesn't add up and wonder why?
Dave

I had 2 things I that popped in to my head.

1) I find it odd that the mast breaks at the top - is this typical??? the sail area is triangular - and gets smaller at top - and as such the forces should get small at the top as well.

2) is it possible that the speaders themselfs "pinched" the mast, deforming it and causeing a weak spot?

is there a torque/moment situation that caused this maybe?

Out of curiosity , when it broke did it break "left/right" or "fore/aft"?

Kev.

[Catigale]

Ill second the loose upper shroud theory, followed by mast pumping, followed by mast failure.....

[Don T]

Hello,
Early Mac 26X's came with swing spreaders. In rough water and gusty conditions the spreaders will swing a bit and cause the mast to pump forward and aft. It also allows the lee shrouds to go slack. So between the pumping fore and aft (read fatigue) and shock loading of the shrouds as they slack and snap back, it is the worst of conditions for having the top snap off. Some early owners had the mast break there when tied to a mooring ball. I received my replacement fixed brackets in the summer of 96 IIRC.

[tlgibson97]

The shrouds were snug. I don't have a way to measure their exact tension but they were as tight as I could get them by hand. There wasn't any slop in them and they weren't so tight you could play a tune on them either.

It broke over the starboard side. That just happened to be the wa the wind was pushing it.

Now that I know that the rig should have been able to handle much more than what I was subjecting it to I guess what's next is get a new mast and make sure it's rigged properly. I won't have the hinged spreaders on the new mast so if that had any effect on the issue it won't be an issue next time. If anyone sees a mast pop up for sale let me know. Would like to get one a bit cheaper than the approx. $1100 it would cost to get one shipped from BWY. I'm not in too big a hurry since this was my last planned outing for the year. Planned to do some cosmetic work and some customization over the winter to have it all set for spring.

Thanks everyone for your feedback.

[tlgibson97]

When sailing into the wind the leeward shrouds and backstay got pretty slack. I'm afraid my lack of experience comes into play to know whether they were too loose or not. I just always understood that it was normal for them to be loose but I couldnt tell you if they were too loose.

[Divecoz]

OK .. snug can be snug and still FAR from proper / balanced tension.. IMHO get a Loos Gauge..
I am not laying blame but strongly suggesting as others have said as well , that the tension was Wrong..We All Really Need to know your location.. Add It To Your Avatar.. I know of an M ( rotating ) mast that is for sale very reasonably I do believe.. NO NOT Mine But I have No Idea where you live..

The shrouds were snug. I don't have a way to measure their exact tension but they were as tight as I could get them by hand. There wasn't any slop in them and they weren't so tight you could play a tune on them either. .

[tlgibson97]

Ill look into a guage to set the tension correct next time. Thanks.

I'm in the Atlanta metro area.

[Obelix]

Everybody is talking about correct tension on the rigging
Could somebody from the factory or somebody in the know at a dealership please specify the correct tensions and how and where the measurements should be taken, using what type of tool
I would like to check my rigging on my 2008 , but can nowhere find exact instructions how to check

Obelix

[seahouse]

http://www.amazon.com/dp/B0000AXNQH/ref=biss_dp_t_asn

This is on my Christmas list- I'm somewhat embarassed at not having one yet.

It's the best price I could easily find for that gauge, and way cheaper than anywhere I could find in Canada (no surprise there). There is a cheaper model - but this one is built to last.If someone knows of a better price - (forget about "used" ones - after all, this thread is all about something "used" with questionable provenance) I'd like to hear about it please.

It's exactly what you need to set correct tension on your stays and rigging.

- Brian.

[Hamin' X]

Since other owners of "early" X's say that they were offered free upgrades, I would call the factory and discuss it with them. They might possibly cover the new mast, since it was a "recall" item. I realize that the won't have to help you out, but hey, they might want some good publicity. Just be nice and non confrontational. Honey, not vinegar.

~Rich