sail-world.com
 
 
News Home Cruising Photo Gallery Video Gallery
Sail-World.com : FX Rig Designer explains the working of the Fathead Rig + Video
FX Rig Designer explains the working of the Fathead Rig + Video

'The versatile FX Fathead rig allows the boat to be powered up for light winds and flattened out at the top end of the wind range.'    Richard Gladwell    Click Here to view large photo

Mackay Boats John Clinton explains how the Fathead Rig works using video taken from a test sailing session in the FX undertaken on Auckland Harbour on Saturday, when winds gusted to a recorded 31 kts.

Fathead rigs had their origins in 12 and 18ft skiffs, and are so-called because of their large square head in the mainsail.

A slightly flatter gennaker design gives the FX excellent handling downwind when the breeze kicks in. -  Richard Gladwell   Click Here to view large photo
They have been adopted into a variety of classes, right up to America's Cup level, because of their ability to carry extra area high up in the rig to give power in light and moderate winds, but allow the rig to depower itself in the bigger breezes as the head twists open.

Although the concept is simple, the sail and rig engineering is not. Getting the sail design to work with the spar package is critical, as is the need to reduce sheet loads on the crew.

Clinton has 30 years experience in sail and rig design, having worked as a sail designer for North Sails, and also for for Southern Spars, specialising in dinghy and skiff rigs in both situations. He's also one of New Zealand's top technical sailing coaches.

In these long, unedited video sequences, John Clinton talks us through the essentials of the FX rig using video from ahead of the boat, side on and astern.

Then in a long downwind sequence, he explains how high speeds are achieved in skiffs like the FX using a combination of rig and sail shape to make the boat sail faster, while remaining in easy control.

As Clinton notes several times in the video, the FX has a mast that is one metre shorter than the 49er, however modern sail and rig design allow the designers to optimise the boat to a crew weight - which in the case of the FX is around 120kg. (Interestingly the maximum weight for lightweight women rowers is only 58kg each - so the FX is optimised for crew only 2kg above the womens lightweight rowing weight).



The outcomes are that sailors can power up the rig in light winds, start flattening it using a downhaul - in a similar way to that used on windsurfer rigs, and then in the top end of the breeze the main is flattened, or depowered. The power in the jib is controlled by the sheet position - which was the purpose of the weekend's test in these quite extreme conditions. Also a lot of the rig power is adjusted through the range by changing the stay tensions. The uppers are loosened as the wind increases to allow the top of the mast to fall off sideways to depower the head.

The FX mainsail is flattened by pulling on a powerful downhaul attached to the luff of the mainsail which induces mast bend. The jib is flattened by adjustment of the clew position. Stays are loosened in a breeze to allow rig bend and depowering -  Richard Gladwell   Click Here to view large photo
The precision of the rig optimistion for a target crew weight, was demonstrated in on the water testing, involving a heavier, 135kg, very competent male skiff crew against the 123kg female crew in 20kt and 25kt winds, sailing two FX's. The test showed that the heavier male crew had an advantage around the above 25kts and the 123kg crew below 20 kts. 'But the differences around the course between the crews in these wind strengths was small', said Clinton. 'My guess is that the cross-over was around 22kts.'

Capsizing a skiff is covered at the end of the video.

Up and downwind capsize situations are covered, again with unedited video sequences, showing how quickly a skiff like the FX can be righted in about 90 seconds, in 25 knots of wind - even with spinnaker set, and when one or both crew have fallen off the boat.

The keys to the quick recovery are the FX's lower rig height and lighter rig weight, and having the skipper and crew correctly positioned. Swimming the boat into a position where the wind can help with the righting operation does help, but is not essential. Just like the 49er, in extreme situations (not seen in the video) the crew holds onto the centreboard in a move known as the Russian or Eskimo Roll, and effectively becomes a bulb keel, preventing the boat from capsizing a second time.

The handing on of sailing tips involving launching, capsizing, and boat handling from the Mens 49er crews has accelerated the progress of Womens crews transitioning into the FX. In both classes, and indeed all skiff classes, correct and precise technique is vitally important to sailing this type of boat to its best. Taking just 90 seconds to right the FX is testimony to the benefits of this sharing of experience.

The performance of the FX rig is expected to lead to the development of a significant 'Weekend Warrior' market as a variety of skiff sailors take to the class, using second hand 49er hulls and dropping the FX rig onto the boat, for a very modest outlay. Currently Mackay Boats already have orders for five FX rigs from Weekend Warrior crews.

The FX features a rig that is one metre shorter than the Mens 49er, but is optimised for a crew weight of less than 120kg -  Richard Gladwell   Click Here to view large photo

Wide wings make the FX easy to tack and gybe in a big breeze. The crew can run smoothly to the opposite side as the boat turns. -  Richard Gladwell   Click Here to view large photo


by Richard Gladwell

  

Click on the FB Like link to post this story to your FB wall

http://www.sail-world.com/index.cfm?nid=96707

9:43 PM Mon 30 Apr 2012GMT


Click here for printer friendly version
Click here to send us feedback or comments about this story.

Click for further information on
2010 Mackay Boats

Related News Stories:

28 Apr 2012  Womens Olympic Skiff proves a point in a 25kt breeze + Video
04 Mar 2012  FX: What the Sailors say about the Olympic Womens Skiff entry + Video
16 Feb 2012  Women's Olympic Skiff Trials: New FX put through paces + Video
27 Oct 2011  Prototype for Olympic Womens Skiff trials has great pedigree
27 Aug 2011  Team Jolly update on the Olympic Womens 470 at Weymouth
15 Jul 2011  470's to have Reunion Dinner at Takapuna - Book Now!
10 Feb 2011  Summer update from Womens 470 Silver medallists - Team Jolly
01 Feb 2011  Brits win NZ 470 Nationals at Takapuna
31 Jan 2011  Images of Takapuna: NZ 470 Nationals - Day 2
22 Dec 2010  49er World Youth Championship for Travemuende






News - USA and the World





























































America's Cup: Challenger calls Competitor Meeting ahead of deadline *Feature by Richard Gladwell Sail-World.com/nz,






U.S. Women’s Match Racing Championship - Top teams to battle
Audi-Tron Sailing Series - Melges 20 fleet ready for action
Volvo Cork Week - Front runners emerge on day 3
Nacra 17 Europeans - Big winds halt racing in La Grande Motte
49er and 49erFX Europeans - Tough end to qualifying phase + Video
New Classification Code for consultation released by the IPC
Clipper Round The World Yacht Race fleet heads for London
Volvo Ocean Race - Abu Dhabi and Team Alvimedi head for England
Rio 2016 in the sights of ISAF Youth Worlds 420 sailors
Exciting new International Audi Melges 20 Ranking System now in play
FISU World University Match Racing Championships - GBR women win gold
2014 Seiko 49er and 49erFX European Championship - Day 2
Volvo Ocean Race teams Abu Dhabi and Alvimedica leave Newport, RI
Half Ton Classics Cup - Champagne conditions on Day 2 + Video
ABYC Fourth of July Regatta - Snipes join the action
Volvo Cork Week - Three bullets for ballistic catapult
Nacra 17 Europeans - Besson and Riou lead the overall standings
Formula 16 World Championship - Aussies claim title in Newport
Vestas Sailrocket 3 - The journey beckons
Clipper Round the World - London to provide emotional heroes welcome
ISAF Youth Worlds - Italians to lead RS:X fleet in Tavira   
Vestas Sailrocket 3 - Over the Horizon   
Foiling Week - Italian Moth Championship - Final results   
NYYC Race Week - Yachting history on display   
Rescued sailors reach shore after dramatic ocean rescue   
Half Ton Classics Cup: Swuzzlebubble out front on Day 1 + Video   
New York Yacht Club Race Week - Yachting history on display   
Volvo Cork Week - Thrilling conditions welcome international fleet   
Nacra 17 Europeans: Success for Italy's Bissaro and Sicouri   
America's Cup: 2017 venue short-list reduced to two Cities   
Formula Windsurfing Youth and Master Worlds overall   
49er and 49erFX Europeans: Pitfalls aplenty on day 1 + Video   
ISAF Youth Worlds - Laser Radial sailors look to join list of legends   
Coville soon to chase solo circumnavigation record in giant trimaran   
Fierce competition at the Meanline Fins Slalom Challenge   
Volvo Ocean Race - Team Brunel opt for experienced winner   
Bakewell-White supermaxi designed to take Transpac's Barn Door Trophy *Feature   
Crew rescued by navy patrol from J/111 racer after Mayday in storm   
Team Alvimedica practice in Newport, RI - Photos   
18 foot skiff European Championship (Open Europeans) - Final results   


For this week's complete news stories select    Last 7 Days
   Search All News
For last month's complete news stories select    Last 30 Days
   Archive News







Sail-World.com  


















Switch Default Region to:

Social Media

Asia

Australia

Canada

Europe

New Zealand

United Kingdom


http://www.sail-world.com/event_images/image/Twitter_logo_small.png http://www.sail-world.com/event_images/image/FaceBook-icon.png  http://www.sail-world.com/event_images/image/RSS-Icon.png

United States

Cruising Northern

Cruising Southern

MarineBusiness World

PowerBoat World

FishingBoating World

 

Contact

Commercial

News

Search

Contact Us

Advertisers Information

Submit news/events

Search Stories/Text

Feedback

Advertisers Directory

Newsletter Archive

Photo Gallery

 

Banner Advertising Details

Newsletter Subscribe

Video Gallery

Policies

 

 

 

Privacy Policy

 

 


Cookie Policy

 

 



This site and its contents are © Copyright TetraMedia and/or the original author, photographer etc. All Rights Reserved.  Photographs are copyright by law.  If you wish to use or buy a photograph contact the photographer directly.
XLXL NEW US
LocalAds   DE  ES  FR  IT