Carbon Mast Breakage

gpdno · Jan 2, 2012

Because they are designing on the edge of lightweight/performance vs structural strength. Sometimes you get too close to the edge and fall off

CF is also quite strong in one direction but weak in the others. It's all a compromise of strength vs weight.

Stu Jackson · Jan 2, 2012

HNY, too.

In "pushing the envelope" design engineers many times are faced with a trade off between strength and weight. In addition, in the case of all manufactured products, as good as "quality control" may be, any small imperfections can create a failure.

Jackdaw · Jan 2, 2012

As stu said, anything will break when pushed past it's design limits.

The last generation VOR boats (VOR 60) were thought of as pretty bullet proof. You could push them 100% all of the time and things would not break. The newer 70s are much more powerful but you have to know when to back off. They can (and do) break if pushed too hard.

jackhartjr · Jan 2, 2012

Could it be that when you are spending other folks money...
If you caught the sarcasim, you did good!
Jack

RichH · Jan 2, 2012

In 'gonads to the wall' racing boats the scantlings or calculated strengths are reduced so that the final weight of the boat is at the absolute minimum so as to optimize 'performance'.

A 'blue water' cruising boat will most times be built and have components at a 'safety factor' of 3 or more (3 times as strong) than the 'historical' applied design criteria that 'worked' ... or didnt break. The gonad boats will sometimes only be 1.5 times as strong .... or less and with no 'reserve strength' inbuilt to accommodate unexpected and 'unforseen' stresses. A coastal design will at about 2X safety factor, an 'inshore' boat at 1.5X safety factor.
Survivability is the result of using the proper 'safety factors' which increase the inherent strength of a design. Ultimate Race boats use less 'safety factor' to save weight.

Bill Roosa · Jan 3, 2012

The safety factor is the crew. if they get cought with their slickers down then bad things WILL happen. The nature of the crew is to push the boat in this kind of racing so those two things are at odds once the wind pipes up enough to break things.
Do you feel lucky?

hwpratt · Jan 3, 2012

gpdno said:
Because they are designing on the edge of lightweight/performance vs structural strength. Sometimes you get too close to the edge and fall off.

Engineering maxim, adapted to the question:

If the mast breaks: It's built too lightly.

If the mast doesn't break: It's built too heavily.

dah · Jan 3, 2012

Screwed

Each screw or bolt which is attached to a carbon fiber mast weakens it and if the attachements are in a pattern, they weaken the mast as does a hatch on a deck weaken the deck. A envelope of stress transfer "()" around an attachment or hatch spreads the load around it such that if the adjoining area is not compensated for, will load failure into the system.

ktm500mx · Jan 3, 2012

el mostro

at the time of the failure puma was 30 miles from the lead boat and just shook out a reef when the mast let go they really wanted to win the whole shebang and just got a bang of the mast coming down instead. they just pushed it too hard.

kloudie1 · Jan 3, 2012

Race re-starts leg 2 tomorrow after the "stealth window" . Should be an interesting 98 mile sprint to the finish line in Abu Dhabi .. Start is at 0600 Z and finish should be 1100 - 1200 Z . Near Real Time tracking coverage will be available on the web site.
http://www.volvooceanrace.com/en/racetracker/rdc.html
The tracker allows ya to see speed and heading and position of the participants..
I was in Boston a couple of years ago for the show there .. Beautiful boats.. fun watching them prep the boats for the voyage.

Nodak7 · Jan 3, 2012

Ducati said:
Could someone please explain to me why those "high-tech" carbon masts keep breaking on those long distance races like the Volvo?

If I were the guy putting up the dough for those expensive race boats I would be pretty ticked at the designers/engineers who built them. And the Volvo is not the first event that this has happened. Is there a better or more durable method to make the rigging last then entire race?

Happy New Year

Ducati, to me it might be as much a problem with the stays and standing rigging. Since the mast by itself is not terribly strong if any of the stays loosen or break the mast is toast. Given the amount of forces these boats endure it could be just a slight misalignment of the stays and spreaders which contribute to the mast failure.

Just my thoughts!!! However I might add that these boats are amazing in their performance!!! As hard as they push their boats it surprises me that they do not have more equipment failures.

Peter Fridman · Jan 3, 2012

As an advertizing gimic, PUMA got a real bang for the money ! Their incident went way beyond sailing folks, the diesel transfer in mid sea, the TRISTAN experience created a new destination for eco travel, eaven the coverage on the web cast was posibly exposing PUMA more than TELEFONICA, this is an advertizers dream come true.

mm2347 · Jan 3, 2012

carbon masts

Ducati said:
Could someone please explain to me why those "high-tech" carbon masts keep breaking on those long distance races like the Volvo?

If I were the guy putting up the dough for those expensive race boats I would be pretty ticked at the designers/engineers who built them. And the Volvo is not the first event that this has happened. Is there a better or more durable method to make the rigging last then entire race?

Happy New Year

carbon fibers as all materials, have properties that have + or - advantages for a given product. For example: They are actually very heavy by equal area when compaired to many of the other fibers often used but also are many times "stiffer". With carbon the mast builders can produce a stiffer mast and at the same time, by using less materal save weight. Unfortionally, any flaw, like air in the layup or a small chip or scratch set up the start of a major break.
Ive never had a carbon mast but have built and used kayak and canoe paddles with carbon fibers as well as Nordic ski poles. Their performance is a huge advantage---untill they break. The problem is that most, if not all of the other racers have them and if you don't you start in a hole.

Benny17441 · Jan 3, 2012

I can understand in match racing where speed is the foremost consideration but in an endurance race where being able to finish the race is the only thing that will put you in contention for first place I don't see why they do not use the heaviest spar they can find to do the job with strength to spare.

Ross · Jan 3, 2012

It is worth remembering that these boats are complete systems. Every component has been considered with regard to its function with every other component. The standing rigging is attached to the mast and the hull, both flex and the standing rigging stretches. The math that goes into the calculations would fill several pages. The hull flexes because the sea is not flat, because the wind loads the sails which in turn load the mast and the mast flexes, this causes the standing rigging to change from a balanced static systen to an unbalanced dyanmic system and those numbers change with every wave and every wind gust and evry time a crew moves from "A" to "B".

tommays · Jan 3, 2012

1/2 of the fleet kept the mast up under the same conditions

If you have ever seen the boats stuffing the bow at 25+ knots of boat speed every few minutes it's kind of amazing they stay toghter at all BUT at least they have gotten better at keeping the canter From falling off

The race is not the same to me anymore now they don't have to finish all the legs under sail and can still win

Ray Bowles · Jan 3, 2012

I thought I read somewhere that PUMA was struck on the backstay by another boat as they were leaving at the start of the leg. If so, I wonder what that might have done, if anything, to cause the mast failure?
Ray

Skipper · Jan 4, 2012

Same reason $100,000 NASCAR engines discard substantialy more parts percentage-wise during a drive than a Honda Accord.