Colligo Titanium Tangs Fractured in Two Separate Dismasting Incidents

[svaletheia]

Both I and a friend have now had titanium mast tangs from Colligo Marine fracture in nearly identical manners as part of individual dismasting incidents.

It is our belief, though not legally proven (yet) that the fracture of these tangs represent a defect in design or material which caused or were a significant component relating to the cause of the dismasting. Both sets of tangs were recommended by the manufacturer as being suitable for the application in which they were installed, and installed under the instruction and inspection of well regarded professional riggers.

I have more detail on my blog if you are curious as to the specifics, rather than just cut and paste here.

http://oddasea.com/archives/142-A-bi...asting....html

In my correspondence, the manufacturer has disclaimed all liability or responsibility and won't even refund the rigging purchase. I will post his email reply if you wish, and over on SSCA you can see his official response and the email he sent me, if you're an SSCA member:

http://www.ssca.org/forum/viewtopic.php?f=4&t=16557

So, if you're considering or have already installed titanium mast tangs, especially from Colligo Marine, beware. Two boats have already lost their rigs where this part was the only noted significant failure subsequent to the dismasting. Pass it on to your friends.

[Brion Toss]

Hello,
First, would you tell us a bit more about the rig? On your site, the pictures show a junk-rigged ketch; has that changed? I'd just like a clear idea of what the rig looked like.
Next, everyone be sure to read John Franta's reply in the second link you posted.
Next, while you say that the tangs were the only significant failure in the dismasting, I would have to count the folded mast as significant, too...
Finally, what was the other boat's rig?
Fair leads,
Brion Toss

[knuterikt]

The junk rig give you a rather long section of unsupported mast..

Are you sure that your lamp post sections have (had) sufficient strength?

http://www.oddasea.com/archives/P3.html

tangs ?


Lamp posts

[svaletheia]

The junk rig is what I turned to after the ketch rig came crashing down 250 miles offshore. It is brand new and was designed by a naval architect. It is not under question and, as it is fully unstayed, has zero tangs or shrouds.

I'm on an iPad now and will respond in more detail when I return from this trip.

The original allied ketch rig was fully serviced before the dismasting and nearly everything was dismantled and all hardware was replaced. The mast crumpled after the tangs let go. I saw/heard that much. Spreaders were intact in the water.

The other boat was a sloop rig also fully serviced with new Colligo tangs.

[jfranta]

Originally Posted by svaletheia

Spreaders were intact in the water.

Dan, with all due respect, this is what I received from you by email on Dec 4.

"Hi John,

Looking underwater, which is where I got the best look at the situation after the reflex of "what just happened" - it appeared that the spreader I could see (the starboard one) was not bent or broken, and as best I could tell (which, sadly, is not for sure, with the ripple effect and the murkyness and the general motion of everything) it appeared that the masthead bent off to starboard pretty much sideways. That's what it looked like coming down and after the fact. But I can't say for sure if there was any fore-aft component to that as I was sitting well aft and in the water everything was all wonky.

I can tell you for sure the entire rig fell down nearly straight on the beam, it did not come down forwards nor aft but pretty much straight perpendicular to the centreline.

--
Daniel"

Again, based on the information you provided of the incident on your boat, including the brackets that we analyzed, there is no conclusive evidence that the brackets were the primary failure mode. In fact, considering the strain rate sensitivity of titanium, a rapid application of a high load, as would be present in a spreader buckling or breaking or possibly some other rig failure modes, would be more in line with the damage shown on the brackets presented. If you have any other information we would certainly like to see it.

We are sorry that our analysis does not concur with yours. Dismastings are difficult as usually most of the data goes overboard, not giving us many opportunities to learn from.

John Franta, Colligo Marine.

[Cayo Quemado]

The Allied Princess 36 would seem to have a transverse rigging load of about 12,000 lbs. I would hope to find 9/32" or even 5/16" wire lowers, but even 1/4" lowers will have a combined break of 15,000 lbs. Daniel says he was verbally assured that the tangs were "massively over-engineered". The e-mail that he posted as coming from John reads

"The first thing that we did was to pull test another set of brackets from the same lot as the brackets you sent. As you know, they tested to over 13,000 lbs break strength."

Does "set" mean a pair? If so they actually seem a bit light to me. Or I've simply misunderstood the issue.

Daniel also referred to taking pictures of the rig in the water before he "let it go". The only pictures I've seen are the broken plates themselves but I can't imagine much of anything would be visible of a mast trailing behind the boat, fouling the mizzen, pounding on the hull while wire cutters were employed in very difficult conditions where time is critical and leverage is difficult to find, plus the constant movement of wires and mast all whipping about in 2 meter seas. "Let it go" indeed.

[jfranta]

If anyone knows anything about any Colligo titanium bracket failures out in the field please let us know. This is the second forum posting that Daniel Collins has made that specifically stated another boat, besides his own, has had fractured Colligo brackets on it. Aside from Dan's boat, we have not heard of any other issues with these brackets. We are very concerned and would like to investigate this alleged incident but we contacted Dan and he refuses to give us any information on the boat mentioned, or its owner. Time could be of the essence here as these are critical components. If you have any information please email customerservice@colligomarine.com or call 480 703 3675.

John Franta, Colligo Mariine

[quote=svaletheia;6872]Both I and a friend have now had titanium mast tangs from Colligo Marine fracture in nearly identical manners as part of individual dismasting incidents.