Awhile back I wrote about the importance and joy of design practice. In that post I suggested that everytime we design something, we are practicing and improving our design skills. And while we do learn from our successful designs, we no doubt learn more from the failures that sometimes litter the path to a project success. If you have done any design practice at all, you have no doubt had a design failure or two. I wonder sometimes why we say doctors are “practicing medicine” and lawyers are “practicing law”, but engineers are just “engineering”. Seems engineers should have the luxury of “practice” one in awhile too. But I digress…
I recently attended a presentation by Dirk Kramers. If competitive sailing is not your passion, particularly on The America’s Cup scale, Dirk may not be a household name in your home. But he has the distinction of being the chief designer for the boat that won the 2013 Amercia’s Cup race. He spent nearly an hour sharing the story of his team’s preparations leading up to the victory. While the race ended with the United States team defending their trophy, the run up to the race is a cautionary tale of boat design specifically, and engineering design in general.
It is easy to watch the America’s Cup race and be amazed at how competing boats maneuver on the water. Even if water craft do not interest you, you have to be impressed at how well the boats and their crews perform on the water. Twin-hull craft are particularly fun to watch since a good stiff wind, coupled with an aggressive angle of attack into it, often lifts one of the hulls out of the water and turns a sedate twin-hull cruise into a slalom thrill ride. In recent years, teams competing in the America’s Cup have universally adopted twin-hull designs. Why? One word: speed. A twin-hull craft is generally faster than a mono-hull design of similar size.
So Dirk’s team started with a twin-hull design and decided to innovate by combining two additional sailing technologies: a fixed sailing wing and hydrofoils. The fixed wing wraps around the mast and makes the boat more maneuverable. Once at speed, the hydrofoils lift the boat hulls until the craft is essentially riding on stilts above the water. So what do you get when you add a wing and hydrofoils to an already fast twin-hull boat? Yep. More speed. But it turns out there is an engineering design price to pay for this boost in performance: instability. Add a fixed wing and hydrofoils to a twin-hull boat and you make it harder to control. While Dirk and his design team knew and anticipated this, they soon discovered the price demanded when the design and performance envelope gets pushed too far into uncharted waters, to use a maritime metaphor.
Dirk and his team set out to create a competition crushing nautical speedster. Members on his team were experts in their individual areas, no doubt some of the best in their fields. Given this pool of talent, was there risk in their approach? Yes, but they felt the risk manageable. The team did their due diligence in design, including running simulations, before building a boat to test. And the first seven testing days went well, but on the eighth day disaster struck. As the test day wound down, the crew lost control of the craft which toppled and started sinking. The fixed wing was destroyed and the rest of the boat badly damaged. Pushing the design and performance envelope crumpled carbon fiber, endangered crew lives, and nearly scuttled the team’s chance to compete in the race, let alone win.
Obviously Dirk and his team recovered and rallied to get back in the running, eventually besting Team New Zealand with a score of 9 to 8. But what design lesson can we learn from Dirk’s story? The answer is obvious: risk is an inherent part of engineering, particularly when dealing with unproven technologies, or combining proven technologies in unproven ways. And real danger often follows. Are these reasons enough to stop taking design risks? Of course not. Innovation in almost any design field requires risk, often by challenging old or traditional ways of doing things. Design risk drives innovation, and innovation often wins races, whether in sports or business. A key design objective, then, is to mitigate risk while still advancing technology – a perfect role for modeling and simulation. Design teams in many industries make their mistakes in simulation long before committing resources to prototype testing. And while failures still happen, the risk is better quantified.