Moonshot, pioneering achievement, absolute speed record... these daring endeavors sound exciting, but they also come with a whiff of risk. And indeed, risk is part of life for pioneers, for designers of innovative concepts, for extreme athletes - and also for entrepreneurs. But these risks can be mitigated. Engineers in the Syroco Lab take safety very seriously, and are incorporating safety features in all their design work, but also in processes.
One thing about safety features and procedures: when designing them, everyone hopes they will never be used. And still, simulations and tests must be carried out rigorously, because if they ever need to be used, they better work!
Looking at the Syroco speedcraft that will shatter the world sailing speed record, a number of passive and active safety features and measures are being built into its design. Below are a few examples.
Early in the design process, the team had the privilege of meeting with the Leader of Patrouille de France, the precision aerobatics demonstration unit of the French Air Force. Through several encounters, this seasoned pilot walked them through a number of elements that are paramount to the safety of men and equipment when aircrafts are flying in formation at high speed and low altitude. The Syroco speedcraft is a boat, but it has many similarities with a plane, therefore all these topics are relevant.
As a consequence, every time the team goes at sea for trials, a safety briefing takes place to define emergency procedures and assign roles to team members in case of an incident or accident. This way, everyone knows what they have to do, and no time is wasted.
The team is also working on emergency braking. Among the solutions being currently investigated, a concept derived from a drag parachute - similar to the ones used by airplanes or drag racing cars, but deployed underwater - seems promising.
Capsule design and pilot protection
The fully enclosed design of the speedcraft body did not happen by chance: it is the only way to efficiently protect the pilots in case of a crash. At 150 km/h, an impact on water is extremely violent. When designing the body of the speedcraft, Syroco engineers ran many computer simulations of extreme crash conditions, measuring the forces that would apply, calculating the deformation and evaluating the breaking point of materials. As part of this process, reinforcements were added to the carbon structure to ensure that the speedcraft would protect its pilots in case such a crash happens, even at full speed.
Special attention is also paid to designing access panels that can be opened quickly in case of an emergency, electrical cutoff systems that are readily accessible even in unexpected postures, etc.
Another topic that was discussed both with Patrouille de France and with sail racing crews is the personal protection and survival gear of the pilots. This includes helmets, impact vests, floatation gear, but also emergency air supply and line cutters. Everyone has witnessed at some point a spectacular crash or capsizing of an America's Cup boat. Some of these dramatic events were more tragic than others, but all have helped shed light on some of the dangers of high-speed sailing.
The “aile d’eau” design chosen for the Syroco speedcraft requires two major elements to work: an airborne kite, and an immersed foil. The opposed traction of the two provides the propulsion force. But Syroco engineers had to think about what would happen if this balance was disrupted. For example, should the kite depower, or should the foil get out of the water. They worked out both urgency and emergency sequences for releasing the traction efforts and returning the speedcraft safely to the surface of the water.
In case of an incident (loss of control during a kiteloop for example), an on-load release has been installed to jettison the foil line and cancel traction on the kite lines. This “level 1” release can be triggered manually from within the cockpit or remotely, and is easy to rearm.
In case of an accident, the team selected a high-performance technology provided by its partner Tethys, an expert in pyro-mechanics. At its core, Tethys designs, develops and produces pyro-mechanisms used mainly as highly reliable ultimate security devices for extreme environments and very demanding applications. Applications are very diverse and include: aerospace, naval systems, nuclear power, fire protection, cash protection, specific airbags, etc. Tethys’ products are generally highly customized to meet the exact need of the application.
Syroco is very grateful for Tethys’ support in designing the emergency release system of the kite. The way this “level 2” emergency release works is quite simple (in safety systems, the simpler the better…). A pair of pyrotechnic cutters are positioned on the kite lines.
Should the pilot or the automated flight control system decide that the conditions are unsafe, a trigger signal sent to the pyrotechnic cutters will cut the lines in less than 5 milliseconds (with a reliability of 99.99%), immediately causing all traction to be cancelled.
Of course, this release mechanism will only be used in case of an emergency, because the lines will then need to be replaced, and the pyrotechnic cutters to be rearmed with a new pyrotechnic load! But be sure that like other safety systems, it is tested extensively before the start of trials, and that no risk is to be taken until it is confirmed that all safety systems work.