Archive | March, 2006

Shosholoza, the soul of sailing

Posted on 31 March 2006 by Valencia Sailing

On Friday, Valencia Sailing had the chance to follow another team training session from a priviledged position. I was the 18th man aboard RSA-83, the yacht of Shosholoza, the first ever America’s Cup challenger from South Africa.

The South African team trained together with United Internet Team Germany, following a schedule that allows both teams to evaluate and improve their performance.

Aboard RSA-83

Never having been aboard an America’s Cup yacht it was impossible to fully grasp its complexity and understand how coordination and teamwork are absolutely necessary in order to make every maneuver.

Unfortunately, Friday’s weather conditions were not ideal with sometimes wind dropping to 4-5 knots and as a result did not provide the perfect setting necessary to fully enjoy these boats.

Stretching exercises before sailing. Valencia, aboard RSA-83, 31 March 2006. Photo taken by Pierre Orphanidis / Valencia Sailing

Dee Smith (left), team manager, tactician and skipper, and Jason Ker (right), chief designer of Shosholoza and father of RSA-83, discussing the day’s tactics and training plans. Valencia, aboard RSA-83, 31 March 2006. Photo taken by Pierre Orphanidis / Valencia Sailing

Muscle power in full use in order to hoist the mainsail. Valencia, aboard RSA-83, 31 March 2006. Photo taken by Pierre Orphanidis / Valencia Sailing

Team Shosholoza starting the day’s sailing. On the left, Tommaso Chieffi who joined Shosholoza last week as new helmsman. At the helms at that moment was Mark Sadler, new skipper of the team. Valencia, aboard RSA-83, 31 March 2006. Photo taken by Pierre Orphanidis / Valencia Sailing

Team Shosholoza training. Valencia, aboard RSA-83, 31 March 2006. Photo taken by Pierre Orphanidis / Valencia Sailing

Grinders provide all the power needed to tack. Valencia, aboard RSA-83, 31 March 2006. Photo taken by Pierre Orphanidis / Valencia Sailing

Grinders provide all the power needed to tack. Valencia, aboard RSA-83, 31 March 2006. Photo taken by Pierre Orphanidis / Valencia Sailing

Shosholoza, the soul of sailing, during training. On the left, Marc Largesse, navigator of the team, together with his inseparable companion, the computer. Valencia, aboard RSA-83, 31 March 2006. Photo taken by Pierre Orphanidis / Valencia Sailing

Shosholoza, the soul of sailing, training in Valencia. 31 March 2006. Photo taken by Pierre Orphanidis / Valencia Sailing

Shosholoza, the soul of sailing, training in Valencia. 31 March 2006. Photo taken by Pierre Orphanidis / Valencia Sailing

Shosholoza, the soul of sailing, training in Valencia. 31 March 2006. Photo taken by Pierre Orphanidis / Valencia Sailing

Shosholoza, the soul of sailing, training in Valencia. 31 March 2006. Photo taken by Pierre Orphanidis / Valencia Sailing

Shosholoza, the soul of sailing, training in Valencia. 31 March 2006. Photo taken by Pierre Orphanidis / Valencia Sailing

The training

The training shcedule depends on the needs of the team or is agreed upon by both teams in case of a joint session. For obvious reasons, we are not allowed to go into further details.

Shosholoza, the soul of sailing, training in Valencia. 31 March 2006. Photo taken by Pierre Orphanidis / Valencia Sailing

Shosholoza, the soul of sailing, training in Valencia. 31 March 2006. Photo taken by Pierre Orphanidis / Valencia Sailing

Shosholoza, the soul of sailing, training in Valencia. 31 March 2006. Photo taken by Pierre Orphanidis / Valencia Sailing

Shosholoza, the soul of sailing, training in Valencia. 31 March 2006. Photo taken by Pierre Orphanidis / Valencia Sailing

Shosholoza, the soul of sailing, training in Valencia. 31 March 2006. Photo taken by Pierre Orphanidis / Valencia Sailing

Shosholoza, the soul of sailing, training in Valencia. 31 March 2006. Photo taken by Pierre Orphanidis / Valencia Sailing

Shosholoza, the soul of sailing, training in Valencia. 31 March 2006. Photo taken by Pierre Orphanidis / Valencia Sailing

Shosholoza, the soul of sailing, training in Valencia. 31 March 2006. Photo taken by Pierre Orphanidis / Valencia Sailing

Shosholoza, the soul of sailing, training in Valencia. 31 March 2006. Photo taken by Pierre Orphanidis / Valencia Sailing

Shosholoza, the soul of sailing, training in Valencia. 31 March 2006. Photo taken by Pierre Orphanidis / Valencia Sailing

Shosholoza, the soul of sailing, training in Valencia. 31 March 2006. Photo taken by Pierre Orphanidis / Valencia Sailing

Shosholoza, the soul of sailing, training in Valencia. 31 March 2006. Photo taken by Pierre Orphanidis / Valencia Sailing

Shosholoza, the soul of sailing, training in Valencia. 31 March 2006. Photo taken by Pierre Orphanidis / Valencia Sailing

Shosholoza, the soul of sailing, training in Valencia. 31 March 2006. Photo taken by Pierre Orphanidis / Valencia Sailing

Shosholoza, the soul of sailing, training in Valencia. 31 March 2006. Photo taken by Pierre Orphanidis / Valencia Sailing

Shosholoza, the soul of sailing, training in Valencia. 31 March 2006. Photo taken by Pierre Orphanidis / Valencia Sailing

Shosholoza, the soul of sailing, training in Valencia. 31 March 2006. Photo taken by Pierre Orphanidis / Valencia Sailing

Shosholoza, the soul of sailing, training in Valencia. 31 March 2006. Photo taken by Pierre Orphanidis / Valencia Sailing

Shosholoza, the soul of sailing, training in Valencia. 31 March 2006. Photo taken by Pierre Orphanidis / Valencia Sailing

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Shosholoza, the soul of sailing

Posted on 31 March 2006 by Valencia Sailing

On Friday, Valencia Sailing had the chance to follow another team training session from a priviledged position. I was the 18th man aboard RSA-83, the yacht of Shosholoza, the first ever America’s Cup challenger from South Africa.

The South African team trained together with United Internet Team Germany, following a schedule that allows both teams to evaluate and improve their performance.

Aboard RSA-83

Never having been aboard an America’s Cup yacht it was impossible to fully grasp its complexity and understand how coordination and teamwork are absolutely necessary in order to make every maneuver.

Unfortunately, Friday’s weather conditions were not ideal with sometimes wind dropping to 4-5 knots and as a result did not provide the perfect setting necessary to fully enjoy these boats.

Stretching exercises before sailing. Valencia, aboard RSA-83, 31 March 2006. Photo taken by Pierre Orphanidis / Valencia Sailing

Dee Smith (left), team manager, tactician and skipper, and Jason Ker (right), chief designer of Shosholoza and father of RSA-83, discussing the day’s tactics and training plans. Valencia, aboard RSA-83, 31 March 2006. Photo taken by Pierre Orphanidis / Valencia Sailing

Muscle power in full use in order to hoist the mainsail. Valencia, aboard RSA-83, 31 March 2006. Photo taken by Pierre Orphanidis / Valencia Sailing

Team Shosholoza starting the day’s sailing. On the left, Tommaso Chieffi who joined Shosholoza last week as new helmsman. At the helms at that moment was Mark Sadler, new skipper of the team. Valencia, aboard RSA-83, 31 March 2006. Photo taken by Pierre Orphanidis / Valencia Sailing

Team Shosholoza training. Valencia, aboard RSA-83, 31 March 2006. Photo taken by Pierre Orphanidis / Valencia Sailing

Grinders provide all the power needed to tack. Valencia, aboard RSA-83, 31 March 2006. Photo taken by Pierre Orphanidis / Valencia Sailing

Grinders provide all the power needed to tack. Valencia, aboard RSA-83, 31 March 2006. Photo taken by Pierre Orphanidis / Valencia Sailing

Shosholoza, the soul of sailing, during training. On the left, Marc Largesse, navigator of the team, together with his inseparable companion, the computer. Valencia, aboard RSA-83, 31 March 2006. Photo taken by Pierre Orphanidis / Valencia Sailing

Shosholoza, the soul of sailing, training in Valencia. 31 March 2006. Photo taken by Pierre Orphanidis / Valencia Sailing

Shosholoza, the soul of sailing, training in Valencia. 31 March 2006. Photo taken by Pierre Orphanidis / Valencia Sailing

Shosholoza, the soul of sailing, training in Valencia. 31 March 2006. Photo taken by Pierre Orphanidis / Valencia Sailing

Shosholoza, the soul of sailing, training in Valencia. 31 March 2006. Photo taken by Pierre Orphanidis / Valencia Sailing

Shosholoza, the soul of sailing, training in Valencia. 31 March 2006. Photo taken by Pierre Orphanidis / Valencia Sailing

The training

The training shcedule depends on the needs of the team or is agreed upon by both teams in case of a joint session. For obvious reasons, we are not allowed to go into further details.

Shosholoza, the soul of sailing, training in Valencia. 31 March 2006. Photo taken by Pierre Orphanidis / Valencia Sailing

Shosholoza, the soul of sailing, training in Valencia. 31 March 2006. Photo taken by Pierre Orphanidis / Valencia Sailing

Shosholoza, the soul of sailing, training in Valencia. 31 March 2006. Photo taken by Pierre Orphanidis / Valencia Sailing

Shosholoza, the soul of sailing, training in Valencia. 31 March 2006. Photo taken by Pierre Orphanidis / Valencia Sailing

Shosholoza, the soul of sailing, training in Valencia. 31 March 2006. Photo taken by Pierre Orphanidis / Valencia Sailing

Shosholoza, the soul of sailing, training in Valencia. 31 March 2006. Photo taken by Pierre Orphanidis / Valencia Sailing

Shosholoza, the soul of sailing, training in Valencia. 31 March 2006. Photo taken by Pierre Orphanidis / Valencia Sailing

Shosholoza, the soul of sailing, training in Valencia. 31 March 2006. Photo taken by Pierre Orphanidis / Valencia Sailing

Shosholoza, the soul of sailing, training in Valencia. 31 March 2006. Photo taken by Pierre Orphanidis / Valencia Sailing

Shosholoza, the soul of sailing, training in Valencia. 31 March 2006. Photo taken by Pierre Orphanidis / Valencia Sailing

Shosholoza, the soul of sailing, training in Valencia. 31 March 2006. Photo taken by Pierre Orphanidis / Valencia Sailing

Shosholoza, the soul of sailing, training in Valencia. 31 March 2006. Photo taken by Pierre Orphanidis / Valencia Sailing

Shosholoza, the soul of sailing, training in Valencia. 31 March 2006. Photo taken by Pierre Orphanidis / Valencia Sailing

Shosholoza, the soul of sailing, training in Valencia. 31 March 2006. Photo taken by Pierre Orphanidis / Valencia Sailing

Shosholoza, the soul of sailing, training in Valencia. 31 March 2006. Photo taken by Pierre Orphanidis / Valencia Sailing

Shosholoza, the soul of sailing, training in Valencia. 31 March 2006. Photo taken by Pierre Orphanidis / Valencia Sailing

Shosholoza, the soul of sailing, training in Valencia. 31 March 2006. Photo taken by Pierre Orphanidis / Valencia Sailing

Shosholoza, the soul of sailing, training in Valencia. 31 March 2006. Photo taken by Pierre Orphanidis / Valencia Sailing

Shosholoza, the soul of sailing, training in Valencia. 31 March 2006. Photo taken by Pierre Orphanidis / Valencia Sailing

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SUI91 leaves Décision boatyard, destination Valencia

Posted on 30 March 2006 by Valencia Sailing

Alinghi’s third boat SUI91 left Décision Boatyard in Vevey, Switzerland today, 30 March 2006.

The new boat was shrouded in secrecy as it was wheeled out of the Swiss yard on the truck and trailer (in all 25m long), provided by Alinghi’s official supplier, the transport company Planzer, that is shipping it to Valencia, Spain.

SUI91 tucked up in plastic for the long road ahead, seen here crossing the ‘Pont du Fenil’. Switzerland, 30 March 2006. Photo copyright: Ivo Rovira / Alinghi

She is the first of two new boats that the Defender will build for the 32nd America’s Cup in 2007 and has taken 25 boatbuilders from both the boatyard and the Alinghi shore crew almost 20,000 man hours to complete.

Michel Marie, Alinghi shore crew coordinator comments: “Three months ago, Décision received the design files with the shape and to see the result today is exemplary of the standard of construction.” Décision successfully built both SUI64, the 2003 America’s Cup winning yacht, and SUI75, the 2005 ACC Champion, and enjoys a long term working relationship with Alinghi.

Yard director Bertrand Cardis says: “There has been great evolution from SUI64 to 75 and now to 91 in the pursuit of perfection. We continue to learn from one boat to the next and improve the quality each time.” Marie illustrates this fact: “The Swiss standard of precision found in watch making is found here in this boat.”

The trailer and cab carrying the new boat is 25m from tip to tail. Switzerland, 30 March 2006. Photo copyright: Ivo Rovira / Alinghi

SUI91 is due to travel the 1,230 km within a week to join stable-mates SUI64 & 75 in Valencia, where, Marie says: “the shore crew and sailing team are in the starting blocks to get her finished and sailing.”

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SUI91 leaves Décision boatyard, destination Valencia

Posted on 30 March 2006 by Valencia Sailing

Alinghi’s third boat SUI91 left Décision Boatyard in Vevey, Switzerland today, 30 March 2006.

The new boat was shrouded in secrecy as it was wheeled out of the Swiss yard on the truck and trailer (in all 25m long), provided by Alinghi’s official supplier, the transport company Planzer, that is shipping it to Valencia, Spain.

SUI91 tucked up in plastic for the long road ahead, seen here crossing the ‘Pont du Fenil’. Switzerland, 30 March 2006. Photo copyright: Ivo Rovira / Alinghi

She is the first of two new boats that the Defender will build for the 32nd America’s Cup in 2007 and has taken 25 boatbuilders from both the boatyard and the Alinghi shore crew almost 20,000 man hours to complete.

Michel Marie, Alinghi shore crew coordinator comments: “Three months ago, Décision received the design files with the shape and to see the result today is exemplary of the standard of construction.” Décision successfully built both SUI64, the 2003 America’s Cup winning yacht, and SUI75, the 2005 ACC Champion, and enjoys a long term working relationship with Alinghi.

Yard director Bertrand Cardis says: “There has been great evolution from SUI64 to 75 and now to 91 in the pursuit of perfection. We continue to learn from one boat to the next and improve the quality each time.” Marie illustrates this fact: “The Swiss standard of precision found in watch making is found here in this boat.”

The trailer and cab carrying the new boat is 25m from tip to tail. Switzerland, 30 March 2006. Photo copyright: Ivo Rovira / Alinghi

SUI91 is due to travel the 1,230 km within a week to join stable-mates SUI64 & 75 in Valencia, where, Marie says: “the shore crew and sailing team are in the starting blocks to get her finished and sailing.”

Comments (2)

Twin keel, what’s the deal?

Posted on 30 March 2006 by Valencia Sailing

Monday’s launch of USA-87 has raised a great deal of speculation on what’s going on below the waterline at BMW Oracle Racing. To the novice, the yacht looks extremely similar to her predecessors. However amongst the aware, heads are being scratched as clear signs are apparent, this yacht is quite different.

Underneath an AC yacht, what’s going on?
Below the waterline of a classical ACC yacht, there is one keel, and one rudder. Centrally attached to the hull, the 3 metre keel fin supports a 20 tonne torpedo shaped bulb. The rudder is another 2-3 metre fin about 10 metres further toward the stern (back) which turns to steer the yacht. In harmony, these two large fins give the yacht stability and the ability to sail in a straight line. More importantly, it allows the yacht to sail close angles toward the wind by providing ‘grip’ in the water. Until now, over 90 percent of ACC yachts have been built to this specification.

What is a tandem keel?
A normal keel sees the keel bulb supported by a single fixed fin in its centre that attaches to one point centrally in the hull. A ‘tandem’ keel uses two fins, one at each end of a long slim bulb that is connected to the hull at two points. Each keel blade is able to move independently on its own axis, allowing its attacking angle to the water to be adjusted. With this arrangement the yacht sails with no rudder, instead totally relying on the movement of the keel fins to steer.

Sails 20, 29, 31, 59, 78, 87?
The idea of a tandem keel is not new. In fact, in every AC event since 1992 tandem keel designs have actually made it into the water but not all competed in regattas. Oracle’s designer, Farr Yacht Design tasted some success with 1992 tandem keel design NZL20. The New Zealand Challenger made the LV Cup final, only to lose in a cliff hanger series against Italy’s Il Moro Di Venezia. The yacht was fast but difficult to sail, and only performed well in the hands of those who had time to truly understand her. Since that time other yachts trialled these concepts without success and most later changed back to classical arrangements. The current +39 challenger, (SUI)ITA59 started her life as a tandem keel yacht, only to be later purchased and converted by Alinghi to her current format. To this day, a tandem keel yacht has not competed in the America’s Cup Match.

General Benefits
A tandem keel can make a boat faster in a straight line, especially upwind. In essence, being able to adjust the angle of both fins independently reduces drag and increases efficiency. Both ‘lift’ and ‘wave’ drag are reduced meaning twin keels can do the job better than a more traditional single keel design. Other benefits include moving the yachts centre of gravity forward, which increases down force on the bow. Wave drag is reduced with the boat actually creating less wake (disturbance) in the water. It pays to note, the super long bulbs amongst the most successful of recent conventional yachts, are not that different to those used on tandem keel designs of the past. Past Tandem bulb trials may have already influenced modern bulb designs.

General Weaknesses
Historically, the main downfall tandem keel designs have been manoeuvrability issues. This is due to the removal of the rudder, and rather relying on two central fins with limited movement to direct the hull through the water. Once engaged in tactical duelling situations, these designs can be slow to regain their momentum after several manoeuvres in a row. This doesn’t mix well with AC Match racing, as an opponent could attack this as a weakness.

Tandem keels also have a larger wetted surface, meaning more resistance pushing through the water. Also eroding efficiency gain is ‘junction’ drag, which is where the actual fins attach to the hull and keel bulb. These moving parts create areas of inefficiency in their design. Overall, the design gains in a tandem keel have always proved small, and the challenges faced both in engineering and actual sailing have made it a risky choice.

USA87 – What’s raising questions?
On first impressions, there are distinct design differences between USA76 and USA87.

Mast Position – One of the first things we notice, that mast is a long way forward! Some have estimated it at between 2 and 3 metres further forward in this yacht, in comparison to other designs.

Forestay Position – The forestay is the high strength cable that supports the mast from the bow (front) of the yacht, also supporting the Genoa sail. The distance from the bow that this connects into the hull, is far shorter on USA87, than her predecessors.

What is this saying?
When eliminating a rudder from the design, a great deal of ‘grip’ on the water is lost at the back of the yacht. The rudder cancels the ‘spin-out’ effect upwind, created by the mainsail putting pressure on the back end of the boat. A tandem keel requires the force in the sails to balance more centrally in the boat, so the designers must place the sail plan’s centre of effort further toward the bow. They do this by moving the mast, and complete sail plan forward on the yacht. This may go some way to explaining why the mast and forestay on USA87 are closer to the bow.

Use of Bowsprit?
By moving the yachts mast forward, a bowsprit may be needed to provide a better angle in controlling the yachts spinnaker pole. The tip of the spinnaker pole will also extend 2-3 metres further past the bow than a classic design. This bowsprit is legal, and compensates for the extra ‘overhang’ of the spinnaker pole forward. This ‘extension’ provides a strong point further forward than the yachts actual bow, in which to provide downward force on the spinnaker pole ‘tip’. This is required to correctly trim the sail, & safely manoeuvre the pole when turning or ‘jibing’ downwind. We shouldn’t be expecting to see any sails being flown directly from this point.

What’s likely to be beneath the skirts??
It’s hard to say considering other advances in AC technology. Rigs and sails continue to progress in their development, and this affects the design of the hull. USA76 was Bruce Farr’s interpretation of V4 of the AC rule. USA87 may simply show some new Version 5 thinking in how the mast, sails, keel and bulb are positioned on the hull. What we have seen doesn’t necessarily confirm a Tandem keel.

It’s obvious that Farr has been given a license to think by the BMW Oracle team. The frightening upwind advantage seen from Alinghi’s SUI75 last season may have heightened the sense of urgency to push design parameters further. This is a natural trial and error process always seen in the America’s Cup, and is what produces champion yachts. BMW Oracle will get a good initial feel for the performance of USA87 over the next few weeks, and use that experience to make a decision on her debut. This will not only depend on her initial performance data, but also on the launch of other competitor’s yachts. Already we’ve seen Luna Rossa’s willingness to show their hand in the next Act, but the chance of BMW Oracle and others following suit is still to see. The question remains, if USA87 is a ‘rocket’, will Chris Dickson, CEO and skipper of BMW Oracle Racing, keep his cards close to his chest?

Patrick Carpenter. Valencia, 30 March 2006

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Twin keel, what’s the deal?

Posted on 30 March 2006 by Valencia Sailing

Monday’s launch of USA-87 has raised a great deal of speculation on what’s going on below the waterline at BMW Oracle Racing. To the novice, the yacht looks extremely similar to her predecessors. However amongst the aware, heads are being scratched as clear signs are apparent, this yacht is quite different.

Underneath an AC yacht, what’s going on?
Below the waterline of a classical ACC yacht, there is one keel, and one rudder. Centrally attached to the hull, the 3 metre keel fin supports a 20 tonne torpedo shaped bulb. The rudder is another 2-3 metre fin about 10 metres further toward the stern (back) which turns to steer the yacht. In harmony, these two large fins give the yacht stability and the ability to sail in a straight line. More importantly, it allows the yacht to sail close angles toward the wind by providing ‘grip’ in the water. Until now, over 90 percent of ACC yachts have been built to this specification.

What is a tandem keel?
A normal keel sees the keel bulb supported by a single fixed fin in its centre that attaches to one point centrally in the hull. A ‘tandem’ keel uses two fins, one at each end of a long slim bulb that is connected to the hull at two points. Each keel blade is able to move independently on its own axis, allowing its attacking angle to the water to be adjusted. With this arrangement the yacht sails with no rudder, instead totally relying on the movement of the keel fins to steer.

Sails 20, 29, 31, 59, 78, 87?
The idea of a tandem keel is not new. In fact, in every AC event since 1992 tandem keel designs have actually made it into the water but not all competed in regattas. Oracle’s designer, Farr Yacht Design tasted some success with 1992 tandem keel design NZL20. The New Zealand Challenger made the LV Cup final, only to lose in a cliff hanger series against Italy’s Il Moro Di Venezia. The yacht was fast but difficult to sail, and only performed well in the hands of those who had time to truly understand her. Since that time other yachts trialled these concepts without success and most later changed back to classical arrangements. The current +39 challenger, (SUI)ITA59 started her life as a tandem keel yacht, only to be later purchased and converted by Alinghi to her current format. To this day, a tandem keel yacht has not competed in the America’s Cup Match.

General Benefits
A tandem keel can make a boat faster in a straight line, especially upwind. In essence, being able to adjust the angle of both fins independently reduces drag and increases efficiency. Both ‘lift’ and ‘wave’ drag are reduced meaning twin keels can do the job better than a more traditional single keel design. Other benefits include moving the yachts centre of gravity forward, which increases down force on the bow. Wave drag is reduced with the boat actually creating less wake (disturbance) in the water. It pays to note, the super long bulbs amongst the most successful of recent conventional yachts, are not that different to those used on tandem keel designs of the past. Past Tandem bulb trials may have already influenced modern bulb designs.

General Weaknesses
Historically, the main downfall tandem keel designs have been manoeuvrability issues. This is due to the removal of the rudder, and rather relying on two central fins with limited movement to direct the hull through the water. Once engaged in tactical duelling situations, these designs can be slow to regain their momentum after several manoeuvres in a row. This doesn’t mix well with AC Match racing, as an opponent could attack this as a weakness.

Tandem keels also have a larger wetted surface, meaning more resistance pushing through the water. Also eroding efficiency gain is ‘junction’ drag, which is where the actual fins attach to the hull and keel bulb. These moving parts create areas of inefficiency in their design. Overall, the design gains in a tandem keel have always proved small, and the challenges faced both in engineering and actual sailing have made it a risky choice.

USA87 – What’s raising questions?
On first impressions, there are distinct design differences between USA76 and USA87.

Mast Position – One of the first things we notice, that mast is a long way forward! Some have estimated it at between 2 and 3 metres further forward in this yacht, in comparison to other designs.

Forestay Position – The forestay is the high strength cable that supports the mast from the bow (front) of the yacht, also supporting the Genoa sail. The distance from the bow that this connects into the hull, is far shorter on USA87, than her predecessors.

What is this saying?
When eliminating a rudder from the design, a great deal of ‘grip’ on the water is lost at the back of the yacht. The rudder cancels the ‘spin-out’ effect upwind, created by the mainsail putting pressure on the back end of the boat. A tandem keel requires the force in the sails to balance more centrally in the boat, so the designers must place the sail plan’s centre of effort further toward the bow. They do this by moving the mast, and complete sail plan forward on the yacht. This may go some way to explaining why the mast and forestay on USA87 are closer to the bow.

Use of Bowsprit?
By moving the yachts mast forward, a bowsprit may be needed to provide a better angle in controlling the yachts spinnaker pole. The tip of the spinnaker pole will also extend 2-3 metres further past the bow than a classic design. This bowsprit is legal, and compensates for the extra ‘overhang’ of the spinnaker pole forward. This ‘extension’ provides a strong point further forward than the yachts actual bow, in which to provide downward force on the spinnaker pole ‘tip’. This is required to correctly trim the sail, & safely manoeuvre the pole when turning or ‘jibing’ downwind. We shouldn’t be expecting to see any sails being flown directly from this point.

What’s likely to be beneath the skirts??
It’s hard to say considering other advances in AC technology. Rigs and sails continue to progress in their development, and this affects the design of the hull. USA76 was Bruce Farr’s interpretation of V4 of the AC rule. USA87 may simply show some new Version 5 thinking in how the mast, sails, keel and bulb are positioned on the hull. What we have seen doesn’t necessarily confirm a Tandem keel.

It’s obvious that Farr has been given a license to think by the BMW Oracle team. The frightening upwind advantage seen from Alinghi’s SUI75 last season may have heightened the sense of urgency to push design parameters further. This is a natural trial and error process always seen in the America’s Cup, and is what produces champion yachts. BMW Oracle will get a good initial feel for the performance of USA87 over the next few weeks, and use that experience to make a decision on her debut. This will not only depend on her initial performance data, but also on the launch of other competitor’s yachts. Already we’ve seen Luna Rossa’s willingness to show their hand in the next Act, but the chance of BMW Oracle and others following suit is still to see. The question remains, if USA87 is a ‘rocket’, will Chris Dickson, CEO and skipper of BMW Oracle Racing, keep his cards close to his chest?

Patrick Carpenter. Valencia, 30 March 2006

Comments (4)

Twin keel ?

Posted on 29 March 2006 by Valencia Sailing

We will feature later today a very interesting and incisive article on the use of a twin keel in the America’s Cup, written by our good friend Patrick Carpenter, New Zealander and adopted Valencian. Patrick is extremely knowledgeable about America’s Cup yacht design as he is in charge of the modification of NZL-38, right here in Valencia.

In the meantime, take a look at USA-76 and USA-87 being towed out of Port America’s Cup on Wednesday morning, for the team’s two-boat training and testing session. They were taken at the exact same spot, a few seconds apart. Even a layman can observe the differences in the painting of the hull.

USA-87 being towed out of Port America’s Cup on Wednesday morning. Valencia, 29 March 2006. Photo taken by Valencia Sailing

USA-76 being towed out of Port America’s Cup on Wednesday morning. Valencia, 29 March 2006. Photo taken by Valencia Sailing

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Twin keel ?

Posted on 29 March 2006 by Valencia Sailing

We will feature later today a very interesting and incisive article on the use of a twin keel in the America’s Cup, written by our good friend Patrick Carpenter, New Zealander and adopted Valencian. Patrick is extremely knowledgeable about America’s Cup yacht design as he is in charge of the modification of NZL-38, right here in Valencia.

In the meantime, take a look at USA-76 and USA-87 being towed out of Port America’s Cup on Wednesday morning, for the team’s two-boat training and testing session. They were taken at the exact same spot, a few seconds apart. Even a layman can observe the differences in the painting of the hull.

USA-87 being towed out of Port America’s Cup on Wednesday morning. Valencia, 29 March 2006. Photo taken by Valencia Sailing

USA-76 being towed out of Port America’s Cup on Wednesday morning. Valencia, 29 March 2006. Photo taken by Valencia Sailing

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