Technical
If it’s good enough for the Cup...
No different to the service they offer their most demanding grand prix clients, Offshore Spars now offers all racing customers the opportunity to precisely match mast bend characteristics to sail design... as standard
After almost 50 years buildingmasts for everything fromcruisers to America’s Cup winners, Offshore Spars and its new owners are combining decades of experience with the latest innovations fromthe aerospace and automotive industries. The result is “bespoke” rigs, masts that perfectly match each boat’s righting moment and sails. ‘Back in the early days with aluminium, you’d just pick a mast section that matched your specs,’ chief technology officer (CTO) Trent Justice explains. ‘Now we're customising the entire carbon laminate so that at a particular wind load, the bend matches the mainsail’s luff curve.’ The best example of this
innovative process is the new mast Offshore Spars built for Black Pearl, a Botín 56. ‘They lost their rig in the RORC Transatlantic Race so they approached us,’ Justice says. ‘It was quite a tight timeline, which always makes a bit of extra challenge. But we delivered in the timeframe we set out, without sacrificing our three- and-a half-month design period.’ Sailpack software models how
a boat will sail through different wind ranges with different sail
58 SEAHORSE
configurations. One huge benefit, currently unique to Sailpack, is that it can calculate the stretch on multiple cables through multiple wind ranges whilst changing sails. Offshore Spars can provide a sailing tune instead of just the dock tune, which takes the guesswork out of setting up the rig for a particular day's racing. Perfecting amast’s specification
details requires collaboration, a massive change fromwhat Justice calls the traditional approach: ‘First the customer finds a boatbuilder and a designer, then they choose theirmast builder and lastly they figure out the sailmaker,’ he explains. ‘But the interaction between us and the sailmaker is really important, because we need to understand how they want the sail to perform. For Black Pearl, the design process kicked off straight away, with countless calls to get a spec together.’ Like a growing number of industry players, Offshore Spars uses Sailpack to coordinatemast design with Carbo-Link and Doyle Sails. Once they’ve agreed on the maximum load and a factor of safety, the most important characteristic is stiffness. ‘That determines how the
Above: after the Botín 56 Black Pearl lost her mast during the RORC Trans- atlantic Race, Offshore Spars built a replacement on a tight timeline. The new mast is more durable than the original but also 11kg lighter with a lower centre of gravity
mainsail’s luff curve will change through the wind range.’ Justice says the Black Pearl team is truly professional and terrific to work with, but there was a special challenge for this project. ‘They were keen to save weight but, more importantly, they did not want to lose another rig! So, a strong, robust rig was the primary focus.’ After consultations with their
project partners, Offshore produced a rig that is more durable but still lighter than the original. ‘We reduced the overall weight by 11kg (4 per cent) and lowered the COG by 300mm,’ Justice explains. ‘And we removed one of the deflectors, which helped with their ORC rating.’ They came up with these specs
thanks to input from Pure Engineering. ‘Pure Engineering works with Team New Zealand, Botín and numerous other designers worldwide,’ Justice says. ‘At Offshore Spars we use them for finite element analysis (FEA). Pure Engineering’s computer power is a massive investment and there's no mast company in the world that could justify it. So, for us to have access to that is huge. They modelled our carbon laminate, then refined it to
KURT ARRIGO/ROLEX
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 |
Page 71 |
Page 72 |
Page 73 |
Page 74 |
Page 75 |
Page 76 |
Page 77 |
Page 78 |
Page 79 |
Page 80 |
Page 81 |
Page 82 |
Page 83 |
Page 84 |
Page 85 |
Page 86 |
Page 87 |
Page 88 |
Page 89 |
Page 90 |
Page 91 |
Page 92 |
Page 93 |
Page 94 |
Page 95 |
Page 96 |
Page 97 |
Page 98 |
Page 99 |
Page 100 |
Page 101 |
Page 102 |
Page 103 |
Page 104 |
Page 105 |
Page 106 |
Page 107 |
Page 108 |
Page 109 |
Page 110 |
Page 111 |
Page 112 |
Page 113 |
Page 114 |
Page 115 |
Page 116 |
Page 117 |
Page 118 |
Page 119 |
Page 120 |
Page 121 |
Page 122 |
Page 123 |
Page 124 |
Page 125 |
Page 126
