Looking forward
to 2021 The annual IRC Congress meeting will be held online virtually in mid-October. IRC Congress is the international group of national rule authorities around the world that look after IRC in their individual countries. We receive reports from the rule authorities and discuss IRC racing and development in their regions. Congress is also the approval body for IRC rule changes; at the meeting proposed rule and rating updates for 2021 will be confirmed and will be published later in the year for sailors to understand the changes.
Top left: bow overhang measurement for the current IRC fleet for the length range 5-15m highlighting a selection of French designs. Top right: upwind sail area/displacement ratio for the same size range with some of the best French designs similarly highlighted
disadvantages with less crew and IRC treats the boat the same as if fully crewed.
There has been much talk suggesting that there is something specific or unusual about these French designs, maybe their bow configuration or a smaller sail plan (sail area/displacement ratio), or their slab keels (with no bulbs), but on deeper analysis by the IRC technical committee such distinguishing characteristics have proven difficult to identify. One area to look at are bow and stern overhang measurements – used to determine the waterline length with designers regularly attempting to trick the rule into assessing a shorter waterline length. However, IRC takes several measurements at the bow and stern and calculates a dynamic sailing length from a combination of this data. The plot of bow overhang against length of the most successful boats is nothing special, sitting firmly in the middle of the IRC fleet. The notable exceptions on our graphs (right) are
the latest SunFast 3300 (Andrieu) and the one-off Nivelt A13 Teasing Machine (now Phosphorus II) with a greater aft longitudinal bow knuckle position (X measurement in IRC). This can reduce the dynamic sailing waterline in both reality and in rating terms but getting that balance right is not easy. Phosphorus continues to do well with her current owner Mark Emerson and his young crew picking up where original owner Eric de Turkheim and his professional French crew left off. The SunFast 3300 is a much newer boat but it has already enjoyed a number of big successes. We will watch her too with interest. The keel type of many smaller IRC boats, including
International Rating Certificate
the French designs, has developed to a flat slab keel with no bulb as this is seen as advantageous, particularly offshore where the focus is on offwind performance and low drag. It’s worth pointing out that for 2020 the IRC formulation was tweaked to help transition ratings between different slab keel types and now uses a keel aspect ratio, leaving some of these boats with a small increase; but this year’s absence of racing means that this has yet to be tested offshore. There have been comments that these French-style designs have a smaller rig with different sail area/displacement ratios – a deterministic factor for yacht power. But if we look at the aforementioned designs in a plot of upwind sail area/displacement ratio we again see nothing remarkable when
compared to the IRC fleet as a whole. It is a similar story with the downwind sail area ratio. Generally these French designs do develop a higher proportion of stability through the hull shape (as opposed to the weight of the hull or keel) and this is a designer choice. However, stability does not seem to pose an issue for the boats in a shorthanded configuration, driven also by the rig and sail selection. Faster and with less drag off the wind and with adequate stability racing upwind with a smaller crew, it’s clearly a successful formula. But not the only one. In 2019 there were growing concerns regarding the
use of water ballast in single and double-handed sailing with the option to have an additional IRC shorthanded certificate in a different configuration. With the growth of shorthanded sailing, the idea of adding low volume water ballast (equivalent to 3 or 4 crew members) was developing in the minds of designers and sailors. Water ballast boats do not represent a large number in the worldwide IRC fleet but we wish to ensure this development is rated appropriately. The IRC technical committee therefore updated the variable (eg. water) ballast formulation for 2020 to prepare for a shift in approach. In conclusion these French designed boats do not flag up any extremes or specifics from a general analysis of design data. There is something that works very well for these boats but we maintain it is a sum of all the parts (perhaps that in itself requires more investigation?) Many of the boats are notionally cruising boats but built to a higher specification and this may be one of the determining factors in their performance, but not a significant advantage compared to crewing skill and training. So, let us talk about the consistent factor in this analysis, sailors from France. As mentioned before, they have grown up sailing in this environment with training grounds such as the Figaro circuit etc. Their results are regularly good in shorthanded events and this is not down to luck. It will be interesting to see how the new offshore double-handed format in the 2024 Olympic regatta will develop the sailors outside of France; hopefully we will not have to wait long to find out with many national authorities already using the offshore circuit as training and selection for their teams... Jason Smithwick, RORC rating manager
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