An interview with JB Braun on North Sails' state-of-the-art sail making
by David Schmidt 6 Jan 2021 16:00 UTC
January 06 2021
JB Braun © Joe Berkele
Since 1957, North Sails has been a leader when it comes to designing and building fast airfoil shapes that translate into racecourse wins. The company's founder, the late, great Lowell North (1929-2019), himself a double Olympic medalist in the Star class (bronze in 1964 and gold in 1968), built a well-earned reputation for three things: winning sailboat races, crafting fast sails, and being an absolute gentleman. North sold the company in 1984, and while his capable hand was no longer on the helm, the company continued to develop ground-breaking products that helped teams and individual sailors win everything from local regattas to the America's Cup.
While North Sails has long made sails for sailors of all stripes, from cruisers to One Design sailors to Grand Prix players, the company's name is forever wed to two of its most iconic and state-of-the-art proprietary sail-building processes: 3DL and 3Di.
The 3DL manufacturing process was created in 1992 and employed articulating, computer-controlled molds to build mainsails and jibs using yarns made out of materials such as aramid, carbon fiber and layers of polyester film. Critically, these yarns and films were thermomoulded to hold their intended shape.
While this process won plenty of pickle dishes, North Sails has never been content to just hit repeat.
As a result, in 2010, the company created a new sailmaking process called 3Di, where filaments of pre-impregnated carbon fiber and ultra-high-molecular-weight polyethylene are laid down on an articulating mold by a printer-like applicator head. Once thermomoulded, the 3Di process creates a seamless, custom-shaped airfoil that's faster, lighter and far less prone to stretching or creeping than the company's older-generation 3DL sails, which North Sails stopped producing in 2017.
Now, eleven-plus years into the 3Di chapter of North Sails' history, the technology has been continuously refined and developed to the point that it has become a performance benchmark in many classes around the world.
I checked in with JB Braun, North Sails' director of design and engineering, to learn more about North Sails' state-of-the-art sailmaking.
Can you bring us up to speed on what state-of-the-art sailmaking looks like in 2021?
The sailmaking industry now uses automation and simulations. We're using simulations and sophisticated methods to help analyze the performance of sailboats, and the sailmaking has followed along with it.
We've gone from lofting sails on the floor with string and chalk and battens to now, at least with North Sails, [making them] with machines. The machines apply materials to a three-dimensional surface in a way that the designer has orchestrated based off the [pre-calculated] sail stresses and strains. And then that material [is] thermal formed into a monolithic sheet.
[This means that] it's not a woven or processed material, it's actually manufactured exactly for the boat and the intended use.
Now there's a whole new set of ways to look at sails, and automation and computer driven. We're designing sails [using tools such as] computational fluid dynamics [and] fluid-structure interaction.
How has 3Di evolved over its 11-year run? Or, in other words, how does a 2021-built 3Di sail compare to one that was built in 2009/2010?
With 3Di we have an unbelievable future ahead of us. We're only scratching the surface on the development application in use, even though it's been around for 11 years [and] has [gone] around the world [many times], [and has] won the America's Cup.
I remember in 2007, looking out my window in Valencia, Spain [during the 32nd America's Cup] and seeing these black sails on Alinghi going, "What is that?"
After that America's Cup in Valencia, I got involved to try to help develop [Alinghi's sailmaking] process into the [3Di] product that we have today.
[I] met with the engineers in Switzerland, and we were able to build sails, however we had a lot of learning to do. So, we tried all sorts of different types of materials, adhesives, structures...some [experiments] produced unbelievable sails, however, as soon as you hit them with something they would explode or things that maybe they weren't great in their shape, but they lasted forever. So, over the years of developing [3Di] and experimenting, we've come up with sails today that exhibit both of those traits. They're unbelievable structures that have the ultimate three-dimensional flying shape, but also the added durability.
We have different product tiers that we've engineered the different types of materials to suit the customer's needs, from Ocean, to Endurance, to RAW, combined with different material types.
There's still much more to learn. We have different material applications.
What our sails do today— we're able to defy physics.
And what I mean by [defying] physics is we're able to take a three-dimensional shape and a membrane that's built with material, and when a load increases —normally things stretch. With 3Di, we've engineered the structures of the sails so they actually can get flatter and [become] more appropriate for the [prevailing] conditions.
What kind of customer benefits does this translate to? Are we talking about lighter sails, sails with better shape-holding characteristics, sails with wider wind ranges, or ones with better longevity? Or, are these attributes not mutually exclusive?
The benefits for our customer [are] specifically on the product tiers. We have different materials that are applied for different product groups. Depending on the size of the boat, the type of sailing, or the goals and the application that [a customer is] interested in, the product tiers are uniquely designed and engineered for that.
Before 3Di Ocean came around, cruising sailors had not experienced a real product innovation in many decades. Now [they] have the opportunity to [buy] a 3Di Ocean sail. It's lighter, it holds its shape better. It has unbelievable technology applied to the design and manufacturing process of it.
In my mind, it's kind of like a revolutionary product that's providing an opportunity for customers to get more out of their sailing.
The same sort of application applies to the other tiers to the Endurance and the RAW tiers, but for different goals. The Endurance sail [is] for a bigger boat or [a customer who is seeking] less stretch [and] higher performance, but [it] also [has to] have the durability of the exterior materials that add some shape resistance and some long-term durability for the more performance-oriented cruiser or racer [who wants] that added sense of security.
And then you have the RAW sails, which is raw. It's [for customers whose only] concern is performance. [They're] willing to give up some of that added durability and take away that weight and have [high-end performance].
Has the pandemic slowed down the evolutionary arch of North Sails' design and build process?
Yes and no.
We've all been adversely or negatively affected by the pandemic. We feel for all the people [who] have had issues like [or pandemic-related] challenges.
For us at North on the design side it's been tough.
On the positive side, we've had the opportunity to take a breadth and look at what we're doing, reevaluate some of the programs and things we've been working on.
Taking that time has made us more focused on identifying [opportunities] and then having the time and the manpower to apply to [these opportunities]. On-the-water testing and on-the-water evaluation has slowed to almost nothing, but filling that gap has been the added simulation and focused design [work] on projects that we've been able [further using] our simulation and analytical tools.
Given that high-level TP52 racing and other Grand Prix regattas have largely been cancelled last year, what kinds of boats and classes have you been focusing your design work on recently?
Even though most, if not all, the racing has been canceled, it is starting to come back at very small levels. We've been focused on these more adventure-style races that are still being planned and the [Vendee] Globe.
The Ocean Race has been postponed. However, there's still lots of development happening there.
We see emerging fleets coming in different areas, [for example,] high-performance boats [that] have been used [for] One Design racing [are] finding a way to enter the rating game where they're playing with the ORC or ORR [rating rules]. There's opportunity to work with those teams, refining the inventories for those boats, and applying that to their use.
So even though some of the mainstream events have been canceled [or] were postponed, there's also the opportunity in other areas. So, we've been shifting our design resources to try to emphasize that.
Where do you see greater potential for development in the next five years—upwind sails or downwind sails? Also, why?
The opportunity for us to continue to grow and develop aerodynamically is out there for [both] upwind and downwind sails. We've seen some big advancements recently with [our] Helix Structured Luff and the load sharing in [our] reaching sails.
We're [also] seeing advancements in some of the upwind sails. I think there's opportunity in all the areas, reaching, downwind, upwind. It depends on the goals. If [someone is] looking at just strictly VMG upwind, [they] may have a different solution than if [someone who is] willing to give away a little upwind [performance] and try to gain [speed] reaching].
I think, and it's going to be [an] exciting next few years. There will be lots of development. We're perfectly poised to take advantage of that with 3Di, and the opportunity that presents for all of our designers and customers alone.
Are you seeing any emerging trends in spar and standing-rigging design that could influence how Grand Prix sails are designed and built in coming years? If so, what are these trends and how do you think they might impact sail design?
Sailmaking, spar making, [and] rigging hardware—it's all being connected together.
Aerodynamics is the engine; it's providing the power. Understanding the power that you have in the loadings—that result drives the design of the rig and the boat. So you want to match that together.
The loads that we're producing and predicting can vary depending on what [a customer's] goals and objectives are. With the Helix sails, where we load share the sails, you can get different loads, but it comes with a give and take. [For example, maybe a customer is] willing to give a little to gain in a certain area.
I think there's going to be continual development the next few years, and that you'll see a lot of new things coming out.
As a sail designer, do you feel that, over the years, you've gained more influence in how other parts of the boat are built?
I think the sail designers are becoming more frontline in the beginning stages of yacht design.
But also, in people's selections of boats, they're wanting certain things and then aerodynamically, we're able to try to help form those things into the right boat. [For example, if a customer wants] a lighter-air performing boat, [we can] go to the higher aspects rigs and higher aspects sails. [But if a customer wants] a super-fast reaching boat with a big wide groove, [we] might start to select lower-aspect sails with lower center of effort, and give away a little efficiency to gain a bigger groove.
We're seeing that people are asking us these questions and we're helping to provide the answers, [which help] create a better package for the customer.
What kind of sail-design challenges does the growing acceptance of hydrofoils and foil assistance present? Can you please explain?
The [horizontal-style] foils are generally considered foil assisted. [These foils share] the displacement of the boat with the water in the hull and the foil.
We talk about lift fractions...if it was 50% lift fraction, 50% of the displacement would be supported by foil assistance, and 50% by the hull.
So the IMOCAs, and The Ocean Race boats are sort of the foil assistance [kind] where they don't have foils on the rudder, so the hulls are taking part of the displacement and the foils are supporting [part of] the boat.
[Conversely,] America's Cup boats [use] hydrofoils where they're all the way out of the water. Generally, these boats sail at much tighter apparent wind angles, because the boat speeds are higher. The tighter apparent wind angles do two things. It increases the apparent wind speed because the boats are faster so the [apparent] wind is higher and the angle is closer to the bow.
That produces unique opportunities for a sail designer.
Are the sail shapes for foiling boats more aggressive than non-foiling boats?
Generally, foiling boats tend to have much more efficient sails, meaning less twist and higher efficiency. So, for a given amount of lift [these sails produce] less drag.
Is there anything else that you'd like to add, for the record?
I think there's a tremendous opportunity to listen and learn.
When you get involved with the big programs, like the America's Cup and The Ocean Race, you learn things.
I think there's going to be some good opportunity to develop not only our product, but also in our tools.
We'll continue to refine and develop [our sail-design and sailmaking] tools, and it is a unique time and opportunity to try to incorporate those ideas and keep furthering our development.