Another Big Canting Keel Boat has Blown-up its Mast

Sometimes McClaren and Ferrari have failures. I think the difference is that there are massive funds and the expertise in Formula One to be able to design out the weaknesses. With matters marine, the technology to detect potential failures in masts and rigging is too expensive to purchase. In addition, independent race scrutineers go through every car before every race.

Are fittings and structural members of the mast etc., taken down and
xrayed or ultrasonically tested before every voyage? I think not.

Rig designers are at the stage the mediaeval stone masons were are in the 12th century. They would build and if the cathedral fell down, they would try something else. Most Master Masons were unable to read and write.

The Octagon of Ely Cathedral The pillars of the Nave originally continued through what is now an open space. Disaster struck on 22 February 1322, when the Norman central tower collapsed. The noise was so great that the monks thought there had been an earth quake. Alan of Walsingham, the monk responsible for the building, was deeply shocked. One of his fellow monks wrote: 'He was devastated, grieving vehemently and overcome with sorrow... that he knew not which way to turn himself or what to do for the reparation of such a ruin.'

Firmer foundations were found further out from the original pillars, and from this evolved the idea of building an octagon surmounted by a lantern. Its width of 74 feet (23m) was too great to support a stone vault, and so it was built in wood and covered in lead. The Octagon's internal height is 142 feet (43m), and its total weight is 400 tons. A masterpiece of medieval engineering, it took 18 years to build.

In the absence of F1 technology to examine every component before every outing, rig designers should be cognisant of the maxim, "To finish first, first one must finish".



Pericles (the Empirical)

 

Yes yes boys..

Some common nonsense:

1 Engineering a mast to withstand a certain load isn´t impossible.
2 Estimating loads is difficult, hence some gear failure in racing boats.
3 Canting keels are generally associated with boats built to a rule. Racing boats (be it canters or not) have generally been built as cleverly (lightly) as possible, thus prone to suffer from structural failure, be it hull, mast, keel or fittings. This is all a compromise between performance and strength - and the first boat to finish is the winner. It´s not all that unfair.
4 Canting keels haven´t been around in the big boats for very long. There are probably still things to learn in the field.
5 Racing rigs will keep coming down from time to time.
6 Herreshoff was extremely happy to see his spinnaker pole explode into matches. This is one way to figure out the loads.
7 There are at least two kinds of good boat races. Ones that roam about carrying Jupiter in their bilge make for excellent races. Light boats that give the exitement of speed and fragility thrill crews and spectators. Someone wants to go 50 knots in a monohull really badly.

These threads are evidence of the importance of progress, failure and the open mind needed to turn the boating people away from always buying that volvo that neighbours don´t have to get upset about.

Goot to get this off my heart. Thanks.

 

Hey Guys I think you have hit the spot.

I guess they are just trying and exploring the boats and rig limits for the next Vendee Globe. The new boats (Open60’s) are much more powerful than the ones from the previous generation and they are still on “uncharted waters”. These races are for them peanuts compared with the big one and I believe they will have the boats ready for that one. In the end, it is sailing technology that will be upgraded and when those uncharted waters become mapped, we all win.

 

Well, MAYBE

We win if suitable, dependable and affordable alternatives emerge from the fooling around with all the canting stuff going on at present.

That might happen if technological advances stall for a bit, allowing some of the ideas and solutions to be filtered down to the everyday guy who can't afford to have a carbon everything on his boat (and might not anyway) even if he could.

If the next end-all, be-all shows up on the racing radar screen before this canting stuff gets filtered down, then it is moot as to its value and you will likely see the rush to commericalize the next great whiff of racing tech so that someone... anyone, can captialize on the so-called, advances. At that point, canters will be relegated to the scrap heap as the crowd rushes onward to another mythical conclusion. Take a long look at the cycles of development in the computer industry and see where yesterday's tech has remained applicable.

Otherwise, it's going to be much like the active suspensions of the F1 cars that effectively went nowhere when it came to the everyday vehicles that you and I drive around town with the family.

Here's a good comparison... When F1 dudes like Ecclestone rule that all their vehicles need to be responsibly propelled by electric drive systems, rather than gasoline powered engines, there "might" be some trickle down applications that develop from that enterprise. That might then become a topic in which we can safely say that we all win, rather than the few who have the disposable cash for their chosen toy expenditures.

I do not see canting keel technology having that kind of global impact for the benefit of a wide latitude of people on this planet. Until that time arrives, if it ever does, then this is just more toys and the associated dreams of making use of those toys. It's no more functionally valuable than last year's hot shot video game.

I'm not against the development of technology, I use various aspects of its benefits all the time. But, let's put it in perspective as to its value and purpose, both in the short term and the relevant long term needs of our existence.

 

Canting Technology = SPEED!

Canting keels have been around for 27 years plus.
THEY have and are now being used on some cruising boats. But their impact has been nothing short of extraordinary in ocean racing! The top raceboats in almost every ocean race and EVERY Round the World race (except the clipper race) use canting keels. They are the single greatest monohull speed producing technology of the last 20 plus years. Boats that use them are just plain fast-in fact: the fastest monohull ocean racers around use them with success after success after success to their credit.
Combined with other technologies they will continue to revolutionize monohull speed at sea!

 

We are not talking about canting keels. We are talking about rigs, rigs that are pushed over the limit (by canting keelers). That will end up developing rig technology and will give us stronger and better rigs for the everyday boat.

About carbon rigs, do you know that Selden has already a production line to make carbon masts? We talk about big production standard rigs for the everyday cruiser. They are not a lot more expensive than aluminium ones, are lighter and can take bigger loads.

 

The operative aspect of this quote is the word.... SOME.

Here we are 27 years into the game and only SOME cruising boats have a keel system such as this?

27 years?

Yes, I'd have to concur, Doug. The technology has made a stupendous impact on sailing for the average guy... The PEOPLE'S CRUISER, if you will.

Here's a list of seaworthy cruising boats as put forth by our esteemed member, Guillermo Gefaell:

http://www.boatdesign.net/forums/showthread.php?t=14860&page=57

After 27 years, are any of these highly respected blue water, monohull cruisers equipped with canting keels? I wonder how many of these designs have rig failure rates equivalent to those being experienced in this discussion?

And before Vega gets in a wad about this last question... I know they are not racing boats... and that's the point. For the technology to have any practical value, it has to have appropriate application to more common place design work. You know, the kind of stuff we "regular guys" use in the things we own and enjoy.

Well, I would respectfully disagree, Vega. If we are talking about rig failures, then we are also talking about that change in boat design which has made the failure rate so obvious. If it isn't the canting keels on these boats, then perhaps you could tell us just what it is?

As for the need for strong rigs; We already have strong rigs that are made from materials that are less expensive and more user friendly than any carbon mast that you see on a typical marina vessel. As the price of oil goes through the roof, (check the world markets for that number) the costs for anything made from petro-chemical based resins is going to escalate with it. Carbon anything is not going to get cheaper, Vega, it's going to get more pricey. More pricey means more out of reach for the average guy and his boating interests.

When one surveys the typical mast material for a boat under $100,000 dollars, one does not see carbon masts everywhere. Aluminum is still the wisest choice for a cost effective mast for a production boat. Having Selden put together a mast shop for the purpose of making carbon sticks is not going to change that function. The numbers are just not there to take the price downward.

What will change that function is if Bauxite suddenly gets scarce, the price for the aluminum raw material shoots skyward and all aluminum becomes spendy like anything made from oil with tiny black fibers in it.

 

If we were living in the 50's you could say the same thing about wooden masts, versus aluminium ones

I am not saying otherwise....but $100, 000 for an ocean going boat? Take a look at the prices of the boats on that list (new) and you will come up with an average of + 350 000 USD.

By the way there are modern ocean cruisers that have Carbon masts, several of them and they are growing everyday.

As an example we can chose an American shipyard, Tartan yachts, that produce boats that I would prefer to any of the boasts of that list. Not that they are not seaworthy boats, but almost all of them are old designs and slow boats. Tartans are seaworthy and reasonably fast boats.

Tartan yachts only make cruising boats. They don’t make racing boats, not even cruiser-racers and their boats are less expensive than most of the boats of that list (size for size).

They say about Carbon masts and cruising boats:

"In 2004, Tartan established another industry first. Our complete line is equipped with carbon-fiber masts as standard equipment…..
Why go carbon? Carbon fiber exhibits a tensile strength greater than that of steel. As a result, our Tartan carbon masts have a substantially greater section modulus than their aluminum counterparts. This superior strength means greater safety at sea."

http://www.tartanyachts.com/technology/technology_view.aspx?UID=3dcab910-dfdf-4689-ba6a-3457d8d29062

 

If alloy 6061 T6 comes with a cert, then what you see is what you get, right!!
with carbon, what you see, can be anything at all, ?

 

Something interesting:
"Given the quantity of carbon fibre required in a construction process which can span 35,000 man hours, you might think that ordering large boxes of the black stuff well in advance would be a smart first move.

But according to Goetz carbon fibre is no longer the key ingredient when it comes to the critical path planning. Instead, the process starts with ordering a large lump of metal."

More at:
http://www.volvooceanrace.org/news/article/2007/october/heartofsteel/index.aspx?bhcp=1

 

Not Right!

I worked for the largest manufacturer of aluminum masts in the Western USA back in the 1980s. Some of the extruded mast tubes we received from very reputable mills would have flaws where the material did not weld together correctly after the spider.

You could not always see these flaws, so they would get past the mill QC check. Sometimes we would not find the flaw until the tube was a finished spar. That was a big wasted expense!

It is possible that some aluminum spars get into the field with these problems. During my time at that spar shop we never had one mast come down, so maybe we were lucky.

Also, if the tube is in the T6 condition when received in the shop, and then spreader bases and gooseneck lugs are welded to it, the condition can drop to T0. None of these masts are re-treated to the original condition.

Our racing masts would use through bar spreader bases, but most of the cruising customers and production cruising boats (big names) would insist on the "stronger" welded bases.

 

http://www.seldenmast.com/frameset.cfm?id=5565&randnum=30920174

Good explanations on their site. Quite a few suppliers in the UK. Useful to know.

Pericles

 

Canting keels have been about for ages on the Open 60's and the mini transats, even self-build canters alowed?
I think its the way forward, just look at the performance of the Volvo 70s!
I know the Farr designed ones were not great, but know they introduced the 'no bomb doors' rule there should be no/less failures.
I think the mast explosion epedemic must be down to the 3/4 big mast producers not predicting accuratley enough or their quility control of carbon layup etc is slipping up, or whatever, I dont think it's down to the canting. Cause the mast on a 50 canter would be feeling similar rig loads to an old school, say, 65/70 footer, so they knew the loads that they had to put up with. Maybe dynamic Inertial loads due to the keel during slamming is distorting the surrounding bulkheads etc and giving slight movement to the stay anchoring points or some such.
I think if some engineers look deeply into frequency response on the loading of the keel and try some damping systems utilising play within the canting ram/s they could really reduce the transmitted stresses caused by the slamming keel's moment?
Maybe,
No,
yes?

 

Canting Keels

Well there is definately a heated discussion on this post. I would like to weigh in with some aspects that haven't been previously discussed.

There seem to be more and more mast failures in all types of rigs especially the canting keel systems. Now as for the reasons there are so many possible scenarios, but the most probable one is that due to the canting keel mechanism and the increased sail area that this allows puts the rig under a higher stress load. As I have read in most cases the lost rigs and masts are happening in conditions where there is a heightened sea state. Which makes sense to me. As you rise and fall over a sea state that is in turmoil it causes every vessel to move off it's intended track in some manner. Now this can cause a Twisting movement in the mast structure mostly from the Spreaders upward, and on other portions of the wave the boat can be in an almost free fall state where it is heading down a wave face at a greater than anticipated speed. This will cause a greater strain on the mast (gravity we can't escape it on earth). Now from looking at the boats initially discussed it seems that most of the dismastings are happening above a set of spreaders. This is interesting. From a physics perspective all things in motion will continue to be in motion. Think on it for a minute and you will understand that as a vessel comes down the wave face and into the trough the hull has stopped falling (in a liberal sense), but the upper portion of the mast still has momentum, and until that energy has to be transferred in some other way. This could relate to some of the dismastings as any weakness in the stucture of the mast is going to be exponentially greater under this stress.

Having been a Search and Rescue Boat driver in the US coast guard I have seen some of the worst scenarios and weather conditions possible. The ocean as we all know is one of the strongest forces on the planet. It will wreak havoc on all that we wish to throw it. I have seen enough Cruising sailboats that have been dismasting in Noreasters, and other major storms. The Technology advances in rigging that will be furthered by the canting keels and other racing inovations will eventually translate to the public cruising sector. Stating that there will never be a need for Carbon Fiber masts or new standing rigging forms is a backwards way of thinking. Additionally canting Keels may never be adapted to the common marketplace and that is perfectly okay. One look at formula one racing and we will all see they race on wide slicks, Who would put that on their car? Racing is Racing and we will always push the limits to be able to go faster.

Now lets talk about some solutions to this issue. As a designer and Racer I have some thoughts of things I am looking into and will be testing. First of all I would love to find out if any of the dismasted boats are noticing any new hairline cracks or weakness to the deck beneath the mast or to the mast step area as a whole. This will point to increased loads on the mast structure. Several things I am looking into are a compression mast in the lower third where as the mast comes under greater pressure and loading that it will have some flex (like a shock) to keep the pressure from damaging the carbon fiber mast. Second and almost important is a Oval mast opening in the deck that allows for a minor bit of rotational deflection also letting the kinetic energy of the mast at points to be transferred in a more gently manner to the boat strucutre.

As with any new technology we have to think of the entire system and all parts that are effected by the technology. Assuming that the Boat crews aren't properly taking care of the boat (come on these are professionals). We have to look at all the issues and parts, there is the Canting keel, There is the Greater Beam allowed by the Keel, There is the Flatter bottoms and Shallower droughts minus the keel. Carbon Fiber masts, and advanced standing rigging. This probably isn't everything but it will catch most of the factors. Looking at just the canting keel is extremely narrow sighted. Allthough it is the technology that makes so much of the other changes possible. Testing will have to be done, and real statistics will have to be kept to understand when and under what conditions. We must also capture the History of the boat itself to understand how these Items could be failing.

If you read all this thanks, I wrote fast so it might not always flow. Sorry...

 

Hey! Great first post
You are welcomed to the forum