Swage fatigue & 3rd pass swaging

[ribbony]

We have just re-rigged the vessel, at last !
But, we now have a problem with the rigger who swaged the hardware to the wire (we provided all parts and wire).

He did 2 pass swaging on a roller swager. Could not achieve specification, had a swage fail (not ours), then told us his machine is faulty and not to use the rig (3 years of restoration work, then the week we were going to first sail)

He wants to do a third pass with the swaging to achieve spec. We know that is not appropiate but we need some written material to support our argument.

Does anyone know of some supportive documentation that goes against a third pass swaging. The vessel is for offshore sailing and the old rig was probably as dependable as this brand new rig.

Ouch !

[seacap]

I know from engineering school that Stainless is very susceptible to fatigue. But I understand your need for documentation. I would contact the guys at Mauri Pro Sailing - Sailboat Hardware, Sailing Gear and Sailboat Equipment or HOME both very reputable company's and ask for a second opinion.

[ribbony]

Thanks Gary

We have sent an email to the gang at riggingonly.com, they certainly appear to have a handle on the rigging situation, looking at their website.

[Talbot]

I would seriouly consider a second opinion from Brion Toss who appears to have a fearsome reputation in this area

[Marco]

Hi ribbony,

dont trust riggers, ever, ever, ever. They are by definition cowboys, they'll do anything to save time and costs. If you are not happy with the swaging, do it all over again with new kit.

This is what my boat looked like after I trusted a rigger that insisted I should not replace the port U toggle after my starboard side one had failed (he had to drive back to the shop to get a second one, probably he could not be bothered). I lost the mast 200 miles offshore, i was alone on the boat and it took me two days to get back to land.

Dismasting Pictures | blogSTAR

[skipmac]

Hi Ribbony,

If you need quick documentation on the problems from swaging you can reference Donald Street "The Ocean Sailing Yacht" and Nigel Calder "Boatowner's Mechanical and Electrical Manual". Both authors are highly regarded and generally acknowledged and experts in the field and. Both books address the issue of work hardening stainless due to multiple passes through a swaging machine and offer similar conclusions.

Single pass hydraulic presses are really the only good option, double pass portable machines probably OK, more than this does not seem to be recommended and can at the least lead to premature failure of the fitting.

[ribbony]

Thanks all.

Brion Toss gave a great response about the situation when we asked last week. It was the hard copy I need so I can back up the specifications from the manufacturer that only state dimensions of completed swages, they do not state that it should be achieved in a single pass (or two), etc.

We had two fittings pressed on by another rigging shop and are very happy with those, as in one press they went straight to specification and no bananas, unlike the other swages done on the faulty machine.

I was thinking of writing an essay titled "DYO rigging for Dummies" !

200 miles offshore, ouch ! No doubt it was not while becalmed in the doldrums.

[ribbony]

Marco - where did the toggle fail ? have you got a photo of the broken toggle. I ask because we have a bit of an issue with the manufacturer of the toggles whe have on the vessel. The pins do not bed into the U shape (under load) but sit clear of the bottom of the u with the pressure resting on two point of contact rather than spreas 180 degrees around the U. We see that there is the potential for problems there as the metal work hardens. Some of the very bad ones were swapped over by the distributor but all their stock is faulty from my perspective.

[Cheechako]

One option would be to buy new long screw fittings, cut the wire and start over if that is how you are rigged... or are you using eyes on the top of the turnbuckle? Rotary swaging is by far the way to go. I assume by roller swaging you mean the fitting is pressed in the longitudinal direction by a roller wheel? (direction of the wire lay) Surprised you cant find rotary down there. The best riggers here in the US have it, but the machines are expensive.

[ribbony]

It is both ends of the wire that need replacement, cutting them off would make them too short. Some wires can be used to make other stays from, but some new wire is necessary. I do not think Searig make long swage/threadded ends. Quite a lot of rigging seems to be done on the move and the riggers seem to like portable gear, though some of the better riggers do have good swage presses in shop.

[s/v Jedi]

The big advantage of a single pass swage (with portable hydraulic swager) is that you can check if it's done right without being present during swaging. It will have the two ridges, no other marks, is straight and within the diameter specs. If a single-pass swage is done right, you can't improve strength with additional passes. Some do it for getting rid of the two ridges (cosmetic) but I don't agree that it's a cosmetic improvement at all.

Multi-pass swages can hide the initial "banana shaped" swage which doesn't correct the problem, it just makes you don't notice it.

I had all swages done by the Swedish rigger in Trinidad (Jonas), even did some myself, on one of those portable/manual hydraulic swagers and everyone was correct first time.... even the ones I did so it isn't a magic art.

cheers,
Nick.

[Marco]

Hi ribbony, I put a picture of the starboard side toggle failure at this link, it's very close range but i guess you'll figure.
Failed U toggle | blogSTAR

This one was spotted before the rig came down, I was beating in 25kts of wind, took the sails down immediately and luckily was only 40 miles from port. Then you read my post, the rigger insisted i didnt need to change the port one and a month later I dismasted.

The port one failed nearer the top of the U, it is difficult to say if the toggles where faulty in the first place or if a hairline crack formed over time until corrosion set in... they were only two years old! Metal fatigue should be unlikely for such "young" equipment, but there is no way to say.

From what you described, if the barrel does not sit properly in the toggle, just forget that rigger. He is a cowboy, he should not consider installing it. The load will concentrate on two points, it will evenctually fail.

I dont want to sound negative, but it looks to me you are in the wrong hands, use a reputable rigger, only put brand new kit, preferably of a mainstream brand that is tried and tested on some production boat. If you have the extra money, change 19 strands for dyform, this will give you 30% extra strength for the same diameter for, well, about 30% extra cost. But a lot more piece of mind.

A lot of riggers will just tell you one thing one day the opposite the next, it just depends from what they have in stock. Whatever they say, check it independently, define some specs and stick to them, if your not happy or if what they install is not as discussed refuse to pay. Refusal to pay gets you a long way.

[ribbony]

Hi Marco

Good photo. That is some blow out in the toggle, ouch !

We have a drought of riggers at this end of Sydney, central and north end of the suburbs is peppered with plenty of riggers (competition is healthy for service provision). To be fair the rigger did not procure the hardware, we got that direct from the importer and though the hardware was rated much higher in BL (breaking load) than the other brands, we found the quality control with the toggles was woefull. That issue will be dealt with in time, for now we need to get the rigging wires sorted out.

[Marco]

Hi Ribbony,

The cost of replacing all my standing rigging, starting from scratch, and buying only the best stuff, would be in the region of 2000/2500 (american) dollars, would be less if you dont upgrade to dyform. As for the U toggle, the damage caused by that u toggle failure, which itself costs about 50 dollars new, was in the region of 30/35 thousand. The math is simple, change all the toggles, it'll be a few hundred dollars you'll never regret spending.

I'm getting ready to race in OSTAR, the single handed transatlantic race from the UK to the US. So, you can see why I would not compromise, it's a long to any land mid atlantic.

You can read a lot about the preparations on the race blog www.blogstar.org.uk I have changed mast, keel, rudder, autopilot, electrics, and a lot more to prepare.