With racing yachts sailing harder and faster than ever before, whose responsibility is it to see that they remain safe?

The desire to win offshore races sometimes results in boats being pushed further than they were intended to be. As a result, we have seen a number of structural issues in coastal and offshore races in the last 18 months that have seen boats either finish in a damaged condition or retire from the race altogether.

The 2004 Sydney Hobart is a good example of this, where the leading two 100ft Maxis failed to finish due to damage in very harsh wind and sea conditions, while the third, a brand new 90ft Maxi, went through to take line honours. It is my understanding that the skipper of the winning boat eased off a little, which enabled him to avoid any race-ending scenario. This race was, however, predominately upwind. On the other hand, the yachts in the recent Volvo Ocean Race, which have experienced all angles of sail and shown boat speeds in the 30kt-40kt range when reaching, have produced high “g” (vertical acceleration) forces and slamming loads on this point of sail, not normally seen in sailing yachts. Conventional ‘rules’ such as those in the ABS (American Bureau of Shipping) Guide for Offshore Racing Yachts are not likely to be applicable to boats that have developed so much further than yachts built at around the time the guide was released in 1986 (and modified in 1994).

So the question must be asked: has the advent of water ballast and canting keels made many of the design procedures being used in the industry out-dated, or are ‘we’ as an industry merely getting pushed or drawn too close to the limit — by the skippers, owners and expectations of the viewing public?

At High Modulus, we were using drafts of the ABS Guide in the early 1980s, before its formal release, and in my experience it has proven to be a very good guide. However, I fully appreciate why the ABS decided it was not a commercially viable option to continue using it as an outright rule for designing and engineering racing yachts under 30.5m (100ft) in scantling length. Primarily the risk of legal recourse would outweigh the financial return. I see particular significance in the word ‘guide’, in that it should be used as a guide for design and engineering, rather than an absolute. I would recommend that even for boats of mid-1980s design vintage, some areas of the yacht should have had higher strength requirements and some higher stiffness requirements — and at High Modulus, we applied them then as we do now. The stiffness increase over and above the guide’s recommendations in various areas may be for performance reasons, to increase the confidence of the crew, or cosmetic in that it can prevent fairing cracking at joints.

Do we need structural rules? Or, should we let the designers address the issue themselves?

I believe rules or guidelines are a good idea. However, as an industry we must ensure that we are not simply looking for an easy way out of a challenging situation. And who would be willing to expose themselves to the liability of formulating and publishing a new set of rules or guidelines?

Without rules for structural scantlings, it is hard for designers to resist the pressure from owners and skippers to drive the weight down and maximise righting moment to increase performance. In most cases it appears very difficult to persuade the skippers to ease off in extreme conditions when they are out there in the ocean, so it will be even more difficult to stop the limit being pushed too far when decisions have to be made on dry land.

The TransPac 52 class is an interesting example where the designer/engineer is required to sign a document saying the boat will meet the requirements of the ABS Guide. However, it is my opinion that the class here has developed scantlings in excess of the minimum requirements of the guide due to the high righting moments achieved, despite having conventional fixed keels and no water ballast.

The class attempted to further discourage the drive to reduce the structural weight by limiting the righting moment. However, from a performance perspective it is an advantage to keep the composite shell and structure to an absolute minimum weight, whilst adding internal ballast in the middle of the boat.

The guide does not have a ‘rule’ for everything, one example being the thickness of the inside skin. While one should consider skin buckling when designing, an extremely thin skin will be subject to other issues such as water penetration on impact with solid objects.

My concern here is what is ‘fit for purpose’, and does the purchaser know what they are buying when the yacht is sold on second hand?

In the absence of a rule or guidelines for a particular yacht, the owner could have it designed for racing at a nominated light airs venue. As such, the structure may be kept very light and not as strong as one might specify for a full offshore race yacht. This is fine as long as the owner sails the yacht as originally intended — but what happens when the boat moves on to a new owner?

The ‘edge’ has come closer to the boats as they have become higher performing and able to cope with greater loads, particularly when tight reaching. As a result, more work needs to be done and further research carried out to review and update what has been an essentially successful guide for many years. The sorts of research I believe should be carried out include measuring vertical acceleration forces, high slamming pressures and other such criterion. In addition, further work can be done to improve individuals’ design procedures. Is it so far fetched to imagine that a group of people from within the industry could come together at some point in the future, with no legal liability, to create such a guide?

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