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Sailing Chandlery 2024 LEADERBOARD

One Design or Two?

by Dougal Henshall 9 Oct 2019 12:00 BST
Science fiction and the Terminator movies introduced us to the notion of shape shifting, but in the real life of the sailing dinghy world, how IS a shape defined? © TriStar

If one design isn't enough, would two designs be too many?

Although the recommendations that came out of the recent World Sailing Trials at Valencia for a new singlehander were destined to end up in the round recycling bin, there was enough detail contained in the reports to trigger some interesting discussions. Full marks then have to go to RS, as their Aero dinghy scored notably higher that the incumbent Laser is terms of strict compliance to the one design ethos.

There is little that is new in this, as the popular mythology has it that those in the know and with the right contacts (and with the right prospects for success) were somehow able to sneak in and measure hull and spar weights, whilst seeking out a Laser that had the truest centreboard slot and the best mast rake. The counter argument is that this doesn't happen in real life, but it certainly does and here I can speak from personal experience. On a number of occasions when a new boat was being put together, I was involved in after-hours visits to a well know mast maker, where sometimes 30 or 40 tubes would be weighed and checked, so that the 'best' one for the rig we wanted could be sourced (make that two tubes - if you are going to play these games it is best that you take a spare!). Did this make a difference and offer that slender edge in performance? Maybe, maybe not, but just the fact that we had been through this process and believed in it ourselves gave a great mental sense of superiority that was no bad thing once out afloat.

Although not the first of the SMODs, it was the Laser that set out making a virtue out of strict adherence to its one design status. Yet in recent years, rumours have been rife that there is a noticeable degree of variation between boats, with this being fuelled when adverts appeared to offer a lighter weight hull, set up with the optimum mast rake. Then there was the Australian versus European Laser... yet somehow the best sailors still do the winning!

And if the truth be told, back in the days of alloy spars, there were huge differences between a tube that had been extruded through a new die and one from an old, well-worn die; the same section could be willowy or something akin to a telephone pole in terms of stiffness.

One could argue that as long as these spars all measured, was this not part of the whole ethos that existed in the days before the SMODs ruled? You could go to any boatbuilder, mast or sailmaker, fit the boat out how you liked, even in a very individual manner if you so desired and as long as it measured and was issued a certificate, then all was well.

For the real innovators there was of course the option of migrating to the development classes, where the situation was even more relaxed.

As long as the boat fitted the parameters of the 'box', as defined by the rules, even the shape was a matter of personal conviction as to what worked best. Most of these classes are better described as restricted development; if you really wanted a near total lack of constraint, then as we saw with the International Moths in And now for something completely different, then this path of hull development could result in a step forward, but equally it could be a heroic failure!

Thankfully, most hull designs would come about as the result of continuous, steady evolution rather than the more radical step change of revolution. As we saw in the International Moth story, even evolution could end up in a 'winner takes all' conflict between two very distinct design philosophies, in this case between the tunnel scows and the skiffs, which then went on to become even more specialised when hulls were distorted even further to create boats that would only really perform in a single set of conditions.

This ended up with at least one derivative of the otherwise successful Magnum lineage being developed with a lot more rocker for competing in what was expected to be a light airs championships to be held on a Swiss lake, whilst another that was intended to be specifically for an event in Japan ended up staying there - in a skip! Of course, successful ground-breaking steps did happen - think of Bob Miller's revolutionary 18ft skiff Taipan - but all too often what initially looked to be a good idea would be recorded in the history of hull development as a cul-de-sac that would soon be forgotten.

However, through both success and failure, our knowledge of the hydrodynamics of hull shapes has increased, aided in part by the ready availability of computer packages that take out much of the guesswork of design, so it has had to be expected that hull forms would move ever closer to an idealised form within the existing parameters.

A good example of how these hull changes can be part of a continuous progression has been well documented within the Merlin Rocket class, where for a long time each new season would reveal the latest design to be demonstrably faster and visibly different to the previous years. However, progress would not always be in the right direction, with even master dinghy designer Phil Morrison hitting a few wrong notes at times, with his less than successful boats driving him rapidly back to the drawing board. But as his design thinking matured, the hull shapes of his NSM I, II. III and IV designs all showed remarkable similarities and careful examination of the plans show the differences between each boat getting smaller and smaller.

In more recent times, the Merlin Rockets have all but standardised around the superb boats produced by David Winder, even though the design is a development of a set of lines first drawn up by designer Ian Holt in the mid-1980s. Over the years these have undergone a number of tweaks, but none are significant enough to qualify as a 'new' design, with the result being that sailmaker Andy Davis is still sailing an un-modified 13 year-old variant to great success.

The stability within the Merlin Rocket fleet have prompted some to suggest that maybe now is the time for the class to close the book on further development, sticking instead to the tried and tested boats that now dominate the active element in the fleet. In some ways the one design route sentiment is understandable, as this would protect the investment that owners have made in their boats and in the class as a whole. Nevertheless, there have been still been some clever attempts in recent years to break the near monopoly exercised by the Winder/Holt boats on the Class, with the highly individualistic innovator Miles James producing his own FRP hull in a shed in North Wales and Jo Richards producing his Superfast Jellyfish.

In the hands of Simon Blake the Jellyfish has claimed some impressive victories, notably at Salcombe, but the problems these new designs face are best represented in the works of Jon Turner, whose Genii design, in the hands of Nick Craig and Alan Roberts, ended an unbroken seven year run of championship wins by the Winders. In the past, a mould breaking championship win such as this would have resulted in a flood of orders for the new design, yet in the cautious times of today, prospective owners seem happier to stick with what they know to be a solid all-rounder. The more recent news that east coast boatbuilder Simon Hipkin had recently completed the tooling for an exciting all new design of Merlin Rocket ought to have sent a seismic shiver through the class, yet even if the Rockatross can demonstrate a clear potential for winning out afloat, it will still face that same entrenched conservatism that blocks the path to the creation of the all-important critical mass and financial success.

All this searching for an idealised hull shape might be fine in the world of restricted development dinghies, where owners live with the understanding that a clever innovative designer might just come up with a new hull shape that has rendered your expensive pride and joy obsolete overnight, but this is a matter of conscious choice made by owners. The same cannot be said of the erstwhile one designs, the classes that make up the bulk of the upper echelons of sailing, where you might well be able to express a choice as to rig, foils and fittings, but the expectation is that the boats themselves are essentially the same. This though may well be another fallacy, as some of the differences in hull shapes in the established one design classes might be bigger than those between different designs in the development area, which rather brings into question the very term of 'one design'.

Sadly, yet again some of the popular myths have more than a little grounding in fact, with one example being the Jack Holt-designed Enterprise.

Back in the glory days for the class, start lines could be crowded by up to two hundred boats, many sailed by the top UK-based sailing talent, all determined to get off the line as best as possible. One of the hot helms reasoned that as you started on starboard tack, if you could get into your lane and break clear before tacking, then this could be translated into a race winning advantage. He used the build tolerances in the hull to create an asymmetric hull that would be faster on starboard than on port, but the age old Elvstrom adage of winning but losing respect saw this as something of a 'one shot wonder'. However, the use of what might nowadays be seen as 'generous' build tolerances to manipulate hull shapes has seen the making of some legendary boats, but equally the end of others.

One class where these changes are big enough to be visibly apparent is the International Contender, which is currently celebrating its 50th anniversary. For the first 15 of those years, building in the class was dominated by Rondar Boats, down in their factory at New Milton on the South Coast.

Ted May, who was the IYRU measurer with the watching brief on the international classes being built at Rondars, was a stickler for ensuring that the class rules were strictly followed, with these decreeing that build tolerances were for amateur home builds only and were not to be used for exploiting the hull shape. Ted's close scrutiny of both moulds and completed boats ensured that all the boats leaving the production line were as close to nominal as possible.

This would all change when another innovative thinker and amateur boatbuilder reasoned that as long as he built the boat himself, he could exploit the hull shape for his own benefit. The trick was to 'cheat the templates', the aluminium profiles used to check the authenticity of the hull shape. With careful design and some very demanding building, the result was a boat called Walkabout, which was based around a much more U shaped hull that had a flatter, lower rockered hull with a minimum waterline beam, yet a maximum beam at the sheerline.

It helped of course that the designer and builder of Walkabout, Steve Daniel, was already an accomplished and hard driving helm from the hot bed of Contender sailing at Weston Sailing Club, but once the boat had won two World Championships plus other titles, it was impossible to ignore the fact that the 'new' shape seemed quicker all round. Steve was both open and honest about what he had done, but as an amateur builder, the build tolerances could be said to apply and as such, Walkabout had no issues in getting a certificate. As the boat racked up even more winning results, it was only to be expected that others would want to follow suite and it was that this point that maybe the IYRU should have stepped in and restored the 'nominal' hull shape in keeping with their own rules.

Instead they kept the whole issue at arm's length and before long, the one design Contender had in effect become a two design, with the reality being that no-one wanted a boat made to the original shape. There have been some other attempts to manipulate the Contender hull shape, including one that included what looked very much like mini chines in the aft sections of the hull (viewed from astern the boat looked very OK-ish). Lest anyone think that these changes to the hull form as so minor as to be insignificant, at a well-known workshop where many a world championship winning boat had been built, there was a debate on whether or not the changes that came with the Walkabout hull shape had reduced the all-round performance, making the boat something of a one trick pony.

With a world championship looming, one multi-championship winning helm went back to the 'old' hull shape, only to find that he was going backwards in more ways than one as his lack of boatspeed in comparison with the newer shaped boats saw him persistently slipping back into the pack. It was the last time a hull was made from the old, original shaped mould!

Nor was the Contender the only international class to flirt with the change from a round bilged to a more 'angular' hull form, as the then Olympic Tornado also appeared from a builder with what some tried to explain away as 'hard spots' in the hull, though in truth they looked to all the world remarkably like chines! Thankfully in both these cases the sailing authorities did for once take a more interventionist approach to ensure that the corners were knocked off.

There is no shortage of examples of there being more to what is popularly described as a one design, as amongst the senior international fleets, the Fireballs and Flying Dutchman, have all seen what are innocuously described as 'tweaks' to the hull form. One of the most senior classes and at the same time, one of the most 'tweaked' of the hull forms would have to be that of the 505, which has been through a large number of iterations whilst still maintaining it's one design title.

Going right back to the earliest days, there were serious concerns that it would be impossible to build a boat down to the minimum weight, only for the UK sailor Larry Marks to finally build a boat that would require correctors whilst ensuring that the hull shape at least stayed the same. With the French apparently having boats that enjoyed a boatspeed advantage, some of the British sailors even conducted a night-time measurement of the championship leading boat, only to find that it was no different to their own.

Still, after a run of French victories in the World Championships, the Australians decided that it was time for the title to go 'down under' which saw them create a dedicated project aimed at the specific target of winning the top event. Builder David Binks would make the hulls, which certainly exploited the template profiles, leaving sailors to look at the new boats with either disdain or wonderment, depending on your views on how the development of the class was progressing.

Once it had become understood that it was all okay with the class to play with the hull shape, a new growth industry sprang up based around the building of these 'new' shapes. Some of the builders took things too far, with one Nordic hopeful falling foul of the templates test when the forward sections were made so fine as to be a failure. It would take time get for builders to get things right, with the otherwise accepted wisdom of 'buying a Parker' coming to grief when the winning boats started to look like an American copy of an Australian boat which itself was a copy of the American version of a UK boat!

Luckily, computers would come along at about this time and one of the first practical applications of the high—tech approach saw a project being undertaken at Southampton University to accurately model the current 505 hull shapes. To everyone's surprise, the most successful hull shapes were coming back to resemble something that was very close to the original lines as drawn up by John Westell in 1953!. This situation would not last for long as in the ongoing battle between Rondars and Parkers, being able to claim a more advanced hull shape became a key part of the marketing message.

Today, with the big spinnaker, raking rigs and high aspect foils, the 505 has to be close to the ultimate all-rounder as it is currently possible to be, with a hull form that has been developed as far as it is possible to develop a 'one design' hull, though some helms have expressed concerns that the finer forward sections in the modern boat can make for a trickier ride downwind in breeze.

As has already been highlighted, with the far greater depth of understanding of hull dynamics and the easy availability of extremely powerful computers, it is only to be expected that the hull shape of today ought to be close to or already at the optimum. But is this the whole story, for in making an optimum hull shape, the question has to be asked 'optimum for what'? It stands to reason that the best hull shape for beating to windward may not be the best when running downwind, or a hull optimised for light airs might struggle if the wind unexpectedly picked up. It would hardly be a good thing for the sport if helms had different hulls that they could select from, depending on the expected conditions at an event.

Some developments have helped, with tee foils on rudders (where allowed) being used to cheat the normal rules surrounding how the hull behaves, but one option that is now being explored would be the ability to modify the hull shape in real time, whilst out racing. The technology is available now and nothing new in the way of design or materials is needed to make this innovative idea into a practical application. It will come as no surprise that the first boat to try shape shifting, manipulating the hull form itself, hails from the innovators in one of the restricted development classes - the National 12 - where it will soon be out on public display competing on a race course.

The legalities of the idea have been explored, with the view so far being that as long as at either extreme of the manipulated shape, that the hull still measured, then it must be legal. Unknowingly, the RYA may have already connived at this development when they waved through a new boat that was originally an old boat but was now clearly a new boat (apart from a deck beam or two and a thwart) but is still registered as an old boat, with their defence being that it was not for them to police these matters; if it swam and went "quack" and measured as a duck, then it was a duck and the breed was immaterial!

The danger will be if the shape shifter proves to be a success, as was proved with Walkabout, everyone will want one. But why not? The Aussie skiffs have multiple rigs, a technique that has now come down through the ranks to the leading single hander of the day where the Aero too has a choice of sail and mast combinations. We have the situation in the 'one-string' Merlin Rocket set up where simply pulling on one string can dramatically change the rake of the rig as a whole.

If pulling on another string significantly changes the shape of the hull (with the key word being how significant is significant) will that just be seen as yet another move towards a greater optimisation, or will it open the door to a hull shape being anything of an infinite variety? After all, if one design isn't enough and two are not too many, why stop there?

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