Carbon is the material that has revolutionized the world of industry, and it has found cross-application from the world of aeronautics to the world of motoring, passing, of course, through the world of boating. Rigid, lightweight and with mechanical properties that, in the field of trees, they make old aluminum pale. And what’s more, carbon allows any custom solution, modification or repair to be made, since artifacts made from this fiber are resin-impregnated composites, it is possible to make solutions on the shafts that aluminum does not allow at all.
Today, carbon masts are no longer just a solution for racing boats, but also a viable, and safe, choice for cruising boats. The reasons for choosing a carbon mast, while taking into account the price difference, as we shall see, are many, even for a boat that is not for racing.
The manufacturers at the international level are now many, and all reliable, although they offer, as we shall see in these pages, different qualities and products, with different costs. Southern Spars and Hall Spars are the big boys, in a market landscape that has many reliable players such as Axxon, Pauger Carbon, LoriMa, and in Ge- nova, Italy, there is MaxSpar.
We talked about this and more with two “gurus” on the subject, Francesco Pizzuto and Fabrizio Lisco of RigPro/Sail Solutions, representing the Southern Spars, Hall Spars and Future Fibres brands.
The former has several America’s Cup campaigns and is one of the best known faces in the tree industry in Italy and beyond. Fabrizio Lisco, on the other hand, is fresh from his adventure in Auckland with Luna Rossa, where he was the rigger of the Italian boat. Two tree wizards, who will reveal the secrets of this material and with whom we will also dispel some false myths, such as the one about carbon trees attracting lightning.
But above all, we will try to understand what are the strengths of a carbon mast, on what kind of boat, by length and type, it is convenient to install them, and how to do a good maintenance. There will be no shortage of surprises.
ON WHICH BOATS IT IS CONVENIENT TO INSTALL THE CARBON MAST
The first question we asked ourselves when we started this chat with Francis and Fabrizio was precise: on what boats does it make sense, by type and size, to install a carbon mast?
According to Francesco Pizzuto, “Even a small boat of a 40- to 43-footer has benefits from a carbon mast because it gives safety and rigidity. When you start sailing in adverse wave and wind conditions the carbon mast provides extra security. In the boat up to 50-55 feet the benefit is perhaps less appreciable, going up above this size on the other hand it helps you a lot with the low center of gravity, less roll and pitching, so we are talking about comfort for the cruiser and not just performance for the racer, since for example, having less inertia at the top makes you more comfortable at anchor. A carbon mast allows you to reduce sails later when there is a strong wind because it does not pluck and move like an aluminum mast. We debunk the fact that the benefit is only for racing boats; in cruising it is significant. Making a comparison with motoring, think of cars with smart suspensions rather than brakes with large diameters-these are solutions that are also needed for production cars. The carbon mast can have this safety role for cruising boats. We are not just talking about weight difference, which is relative, but lower center of gravity, rigidity, perfect sail plan control with the adjustments that the carbon mast allows us. In the end, my cruising boat will pass over the wave with less pitching, but it will also sail better with the motor, more speed, less roll and reduced fuel consumption“.
Of similar opinion Fabrizio Lisco: “Ten years ago I would have told you that for cruising boats over 45 feet or 50 was not worth it, today with the technology advancing and the type of hull construction, which is different in approach and method than in the past, I would tell you that there is no limit below which not to go. Then if we are talking about racing boats, regardless of length and class, from the moment you are looking for extra performance the carbon mast can give you an extra edge“.
HOW A CARBON SHAFT IS BORN
In practice today, there is no limit to installing a carbon mast; its features can be an advantage regardless of the boat. But how is a carbon mast built and how does it really differ from aluminum? “They can be built from male mold to female mold,” Pizzuto says. “The female mold is made in two halves with reinforcements on the inside, while the male mold has a mandrel on which the tube is rolled and reinforcements applied on the outside. Everything then depends on what the client and the site need. Depending on the technical information, sail plan, displacement and righting moment, one can figure out how to design and build the carbon mast that can be made as a perfectly customized product. In the world of aluminum maybe you get 3 or 4 models from a 39- to 45-foot yard all with the same profile masts, because aluminum gives few possibilities for custom solutions. On carbon these limits do not exist. After layering the pre-impregnated fibers, then it goes into the autoclave for baking up to 6 bar pressure and so we have the raw tube, then we go to the cuts for the pulleys, spreaders and all the accessories, then it goes into painting (clear carbon, carbon look or white or asyou want) and at that point it is reassembled with accessories and shipped,” Pizzuto explains.
A QUESTION OF CENTER OF GRAVITY
However, the real advantage of having a carbon shaft is also another. Since the final artifact will be a composite between carbon fiber and resin, it will be possible to modulate the thickness to one’s liking according to the major stress points, as Lisco explains: “On an aluminum profile, the maximum thickness is calculated at the point where the shaft has the maximum load, and this thickness is replicated over the entire shaft, raising the center of gravity upward (it is around 50 percent of the length). If in addition you add local aluminum reinforcements, the center of gravity often goes over 50%. On a carbon profile, on the other hand, by modulating the thickness, the center of gravity can be lowered below 50 percent, especially improving sailing comfort: less heeling, less roll, and less pitching. It is not just a matter of weight: up to a certain size the final weight of the mast does not change much, up to 45 feet we are around 10 or 15% in favor of carbon. What changes in an important way is mainly the center of gravity, it’s not so much the dry comparison in terms of kilograms.” Fabrizio explains, who continues: “The difference in thickness along the carbon mast then gives very varied adjustment possibilities. The adjustment of the shrouds of a carbon mast already comes from the design team that designs the mast, which works out the thicknesses of the- the layup based on the loads and forces on each zone, and provides the shipyard builder with what is known as the summary load, which will then be useful for everyone, including the sailmakers who will know how the mast behaves at a given dynamic or static load. The more precise the design team, the more balanced the final product will be. In adjusting an aluminum mast 90%, on the other hand, it is the rigger’s or sailmaker’s experience, because at the design level the loads to be given to the rigging are not already worked out, we move by small steps until we get the desired result” concludes Lisco.
LIGHTNING IS A FALSE MYTH
On carbon shafts there is then another myth to dispel, that of lightning. Some of the common thinking on the subject wants carbon trees to attract lightning, this is completely misleading. First of all, resin-plus-carbon composite (if it were only carbon, the argument would be different, but there are no shafts made only of fiber) is a worse conductor of electricity than other materials such as steel. Lightning in fact, for reasons related to physical laws, tends to be attracted to the shape of trees or “antennas” in general. If we then throw in the fact that a boat with a carbon mast often has a higher sail plan than one with an aluminum mast, that explains some casisti- ces that, however, have nothing to do with the construction material. Rather on the subject of lightning and carbon, the problems are other, as Francesco Pizzuto explains, “Only the electronic part suffers damage if the carbon shaft is struck by lightning (and if it has a way out). But the shaft itself does not attract lightning; this is misleading. The way out is either a ground plate in water, which acts as a drain for the lightning energy. The damage it can do on a carbon shaft is that lightning passing through, if it doesn’t find its way out, heats up the resin, which softens, the profile can go into a twist, and when the resin cools it takes a different twist. But on carbon there is always a remedy, except in cases of particularly severe accidents, almost unbelievable repairs can be made. In fact, the carbon shaft has no end of life. If an aluminum shaft takes a hit it will almost certainly be unserviceable, on the carbon shaft there is a window of possible intervention, you can even rebuild a broken shaft.”
TREE AND EQUIPMENT
On a cruising boat, there is no contraindication to installing a carbon mast, which as we have seen can significantly improve sailing comfort, but is there a need for an upgrade of the deck equipment that needs to be increased because of the increased rigidity of the mast? This, too, is a myth that absolutely must be debunked, as Fa- brizio Lisco tells us: “The mast has load shapes dictated by rigging, sailing and righting; none of these loads are transferred to halyards and blocks. The only force that affects halyards and blocks is that of the sails, the stiffer they are the more the deck gear will feel the stress. Polyester sails are elastic and therefore more tolerant of halyards; low-stretch, high-tech sails, such as carbon or similar fibers, impose a higher peak load on the halyard. But this does not come from the carbon shaft. Absurdly as far as rigging is concerned, carbon being stiffer, you can sometimes even give lower loads on the rigging than the aluminum mast that has the rigging counteracting its movement.”
Another “hot” topic is that of carbon tree maintenance, but again there is no fragility to highlight, as Lisco further explains, “The care should be the same, whether the shaft is carbon or aluminum. Unfortunately, there is still little culture on this topic. The check at the mast should be like the check at the boat mo- tore, and we should do it every year independent of the building material. Always remember that we are talking about sailboats, and the mast is one of its primary parts, you have to think this way, especially cruisers. We have to think that the shrouds on a cruising boat are in tension all year round, in fact mast works all the time, much more than the engine that we maybe checking all the time. The ‘visual inspection should be yearly when the tree is up, with check of all accessories, full inspection with tree on the ground in the average should be every 3 years. Doing these checks is important because then we will not be forced to do costly maintenance work“, Lisco explains.
We come to what, for pockets, may be the sore point, which is price. There is no doubt about the fact that a carbon shaft is more expensive than an aluminum one, but we have also seen what this difference is justified by. It remains to be understood what a carbon shaft costs on average per meter and what the price differences, even important ones, between the various manufacturers of carbon profiles are determined by, and on the subject we are helped by Francesco Pizzuto’s experience: “The average price per meter depends a lot on the type of boat, can vary greatly, and depends on the structure of the mast and the righting moment it has to bear. To simplify, let’s say that a 50-footer with carbon mast, boom and rigging will cost a total of 100 to 120 thousand euros, but the fork can change a lot depending on the type of boat. Much then goes according to the needs of the site and the client. The price difference also lies in the ability to accurately calculate the final true loads at the design stage, to make a product that is pinpoint accurate and not with excess materia- le that costs and is not needed. As for differences between manufacturers, it depends a lot on how much a manufacturer invests in research and development of a large number of profiles to offer customers according to their needs. For example, the Southern/Hall Group has within it a significant team of engineers and highly skilled technicians working on development, all of which drives up operating costs. Southern invests in a number of profiles and thus has a range of options to offer. The price between a company that, for example, between 40 and 50 feet offers only one or two profiles, and one that offers more, cannot be the same, because the latter will be able to make a mast that as thicknesses will be more accurate for the boat that will have to accommodate it.”
From a technical, performance, and safety point of view, carbon beats aluminum without appeal; in fact, the comparison between the two materials does not even exist. Everything in the end depends on the budget you have and according to the type of use of the boat. If you are going to do long sailing, living aboard for a long time, the comfort that even on a cruiser the carbon mast can give becomes crucial.
FABRIZIO LISCO: from Bari, Italy, professional sailor and racer, rigger for Luna Rossa in the last America’s Cup, with extensive experience in shore team activities.
FRANCESCO PIZZUTO: From Senigallia, he is one of Italy’s best-known “alberai” masters, with several America’s Cup campaigns behind him, and one of Italy’s top carbon mast experts.