Eastern US, sailing south to north: % of distance sailed in true wind speed of 10kt or less = 47% % distance sailed in true wind speed of 16kt or more = 25% % distance sailed at a true wind angle greater than 130 TWA = 50% Not surprisingly, the time spent during the Bermuda races east of the Gulf Stream pushes the average wind speed for this area up but, given that water ballast goes in upwind at TWS 14kt and reaching at TWS 16kt, by far the greatest time is spent on these races not fully powered up and cer- tainly not with water ballast. Hence the new design is targeting optimal upwind/down- wind performance in a range of wind speeds from 8 to 12kt, with a requirement for little or no loss in performance against her more powerful cousins until TWS 15kt upwind and TWS 17kt reaching.
Ballast
While it would appear that the distribution of ballast is less important for our Class 40 sailing off the east coast of the USA, or in the English Channel for that matter (in the spring and summer months) when com- pared to Transat optimised 40s, in practice this isn’t the case. With only 750 litres of ballast available within the rule for a boat that ideally would have 1,200 litres or more (were it allowed) to satisfy a complete range of upwind/downwind conditions, the positioning of water ballast tanks on a Class 40 has a very great effect on the rela- tive performance of the boats upwind and downwind. This is often forgotten by all but a few when reviewing the merits of dif- ferent boats. For example, the performance of what appear from the outside to be identical Marc Lombard-designed Akilaria RC2s is quite different depending on their ballast tank distribution, which does vary from boat to boat. With the 60-footer Kingfisher, OCD were the first to introduce the central ballast tank to the Imoca 60 class as a means of increasing without penalty the righting moment of lighter, narrower designs. This has long since become stan- dard in all Imoca 60s. One innovation in this 40 is that to maximise the range and use of water ballast we have opted for three tanks per side. This approach will help best mitigate any losses against the more powerful Transat boats in the higher wind speeds at a wider range of wind angles. It is a more flexible solution pro- viding essentially an extra gear which the standard two tank layout doesn’t have.
Rig and sailplan
Hall Spars have been chosen as the mast supplier for the project, working closely with OCD, who have also contracted inde- pendent spar designer Chris Mitchell to provide overview, reporting to the client. This approach of independent checks and balances has also been extended to the design of the keel and lift-up rudder systems, being deemed as areas requiring
additional resources in line with the project’s requirement for both innovation and reliability. OCD supplied the prelimi- nary P1 rig file to Hall this month and those who are interested in the class can expect at least two significant differences in the rig on this boat compared to any- thing before seen in the class.
Keel
In line with the most recent Class 40s, the keel fin is a fabricated box section with glass/foam fairings fore and aft. The lower half of the keel fairings is hollow, allowing for the easy addition and subtraction of lead counterweights to trim the boat within the maximum righting moment, minimum displacement band of the rule. CNC machining of the fin is not allowed by the class rules, so while the middle of the fin is faired to templates, the forward and aft fairings will be built in glass from moulds, ensuring complete adherence to the foil design and reducing the cost of subsequent units. The keel fin and bulb are to be built in New Zealand and finished at COY, with Steve Koopman of US-based DK Structures checking and providing oversight.
Kick-up rudders
While we’ve always offered this as an option to clients going as far back as the Kingfisher Open 60, this will in fact be OCD’s first lifting rudder system that has been fitted to any of our designs. For the boat’s target events OCD clearly favoured lift-up rudders over conventional fixed spade rudders because: The additional weight of the lift-up system would be absorbed within the structure mass allowance and will not push the boat over the minimum 4,500kg limit. The frequency and retention of weed on the rudders is more of a problem in this area of the world than in Europe and, because the races are predominantly of shorter duration, time spent dealing with this problem is more critical. Because of the higher percentage of light airs and downwind sailing conditions, Class 40s in the US spend more time than their Transat counterparts at low angles of heel and speeds below ‘hull speed’ where wetted surface area and viscous drag are a more significant factor. As Seahorse readers may well know, making these systems 100 per cent reliable has been an issue for many well-financed, experienced projects and has been a problematic area in both the Imoca 60s and Class 40s. Not wanting or needing to reinvent the wheel, we’ve opted for a system that has ultimately been seen to be successful in the Open 60 world and, to further leave no stone unturned, Steve Koopman is also providing support to our engineering team in this area.
Finally, I’ve just returned from the US again and the excitement among everyone involved is palpable. The spring in Newport RI can’t come early enough.
THE NEXT
GENERATION OF SAILS
AUSTRALIA Sydney T. +61 419433889
T.
australia@onesails.com AUSTRALIA Perth
Pe
T. +618 9331 3910
perth@onesails.com
T.
AUSTRALIA Brisbane T. +61 7 3203 1330
T.
brisbane@onesails.com AUSTRIA Wien
T. +43 1 7065454
office@onesails.at
T.
CHINA T.
T. +852 65063832
china@onesails.com
CROATIA Rijeka T.
AT
T. +385 (051) 289179
croatia@onesails.com
CROATIA Split T.
AT
T. +385 (0)21 398 676
croatia@onesails.com
T. +61 419433889
mati@onesails.com
ESTONIA T.
GERMANY Travemünde T.
AT
Levington T.
AT T. +49 04502 2038
germany@onesails.com GREAT BRITAIN EAST
T BRITAIN EAST TA
T. +44 (0)1473 659 878
east@onesails.co.uk
GREAT BRITAIN SOUTH Hamble
T BRITAIN SOUTH TA
T.+44 (0)2380 458 213T.+44 (0)2380 458 213
south@onesails.co.uk
HONG KONGHONG K T.
KO T. +852 81981784
hongkong@onesails.com HUNGARY Balaton
RY +36 84 340 705
hungary@onesails.com INDONESIA Bali
T. +6281916463561 T.
indonesia@onesails.com ON
ITALY La SpeziaTALY
T. +39 0187 631515
laspezia@onesails.com
JAPAN Okayama-ken T. +81 (0)865-68-2121
japan@onesails.com
PA
MALAYSIA Seri-Manjung Perak T. +60 164115151
AY YS
malaysia@onesails.com MONTECARLO
T. +377 97 98 26 65
montecarlo@onesails.com NETHERLANDS Huizen
T. +31 (0)6 53 78 65 54
info@onesails.nl
NEW ZEALAND Auckland T. +64 21 2804378
newzealand@onesails.com NORWAY
WA AY Kristiansand T. +47 380 62 600
norway@onesails.com RUSSIA Mosca
T. +7 495 364 8796
russia@onesails.com
SINGAPORE T. +65 65424246
singapore@onesails.com SLOVENIA Materija
T. +386 (0)5 618 11 00
slovenia@onesails.com
SPAIN Mallorca PA
T. +34 971 604 290
palma@onesails.com
SWEDEN Helsingborg T. +4642-162656
sweden@onesails.com SWITZERLAND
Genthod - Geneve T. +41 79 120 65 35
switzerland@onesails.com TURKEY Bodrum
T. +90 532 242 30 49
turkey@onesails.com
EXCLUSIVE CONTINUOUS STRUCTURAL FRAME COMPOSITE TECHNOLOGY
WWW.ONESAILS.COM
info@onesails.com SEAHORSE 41
W..O
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68 |
Page 69 |
Page 70