Meet the Strandbeests
Photo Credit - Loek van der Klis
Fragile, ungainly, and making their slow, creaky way across the beaches of Holland, Theo Jansen’s Strandbeests are constantly evolving.
Intricately composed from lengths of PVC tubing, the Dutch kinetic artist has been cultivating his creatures since 1990, with the ultimate goal that one day herds of his beasts will be set out to roam the beaches free of his input, living their own lives out on the sand. Jansen even talks of giving his creatures artificial intelligence, allowing them to navigate over and around any obstacles in their path.
Powered only by the wind that blows in off the sea, Jansen’s animated sculptures are a seamless fusion of art and engineering, with articulated legs that carry them safely across the sand. Gossamer fine ‘wings’ catch the energy of the wind and pump up and down, driving their feet beneath them. The beasts themselves are designed to walk sideways across the beach, their noses pointed directly into the wind. Some are even kitted out with a primitive ‘logic’, sensing changes in terrain, and forcing a change in direction to ensure their safety.
Making them move
In order to transfer the energy captured from the wind into kinetic energy that can drive the beasts forwards, the structure of each of the beasts’ limbs is vital. Very simply put, to understand the motion of the creatures, we must think of the creatures’ spines like the crankshaft of a car. As the sail-like wings fill with wind and start to pump, they feed energy into the spine, which, like the crankshaft in the engine of a car, begins to rotate. Instead of pistons, the spine has several legs attached to it, each of which is made up of eleven different sized rods. The rotation of the spine drives these legs around in an almost elliptical shape, bending at the knee, and moving the creature forwards across the hard sand in a level gait.
The efficient motion of the beasts means that heavy loads can be moved even with a very small external force.
Animaris rhinoceros for example, weighs in at around 3.2 tonnes, and yet can be moved by just one man, and walks with ease on the wind alone.
So devoted to his beasts is Jansen, that their evolution has spawned many different species, each adapted in their own way, and raced against their predecessors. Design concepts from the winning beasts are taken on to inspire future generations, just as changes to the genetic code have resulted in the evolution of nature over time.
Creatures such as Animaris percipiere for example have the capacity to store the energy of the wind. The beating of the wings forces air into racks of plastic lemonade bottle lined up along the creatures spine. As the tide draws in and the wind falls away, this hidden energy store gives the beasts the one last push needed to drive them away from the sea, seeking refuge from the tide in the sanctuary of the dunes.
Another adaptation is the development of primitive antennae, which can detect a change in terrain, forcing a life-saving change in direction. These feelers are made of narrow tubes, which, under regular conditions, will continuously suck in air. As the creatures near the sea and the tubes suck in water instead, resistance is created in the pipe, allowing the beast to ‘feel’ the danger ahead. This sense triggers the immediate release of stored air, forcing the animal to walk away in the opposite direction, and away from the sea where it would rapidly drown.Aside from the perils of the ocean, the biggest enemy of Jansen’s creatures is the weather, and in particular, the storms that buffet the Dutch coastline. One creature, those of the Apodiacula genus, has evolved an innovative solution to this, and when strong winds are detected, will trigger the hammering of a pin into the sand, and holding it in place until the storm has passed.
Although the animals currently still need a lot of additional input from their creator, Jansen is confident that in just a few short years, they will be able to survive indefinitely, completely unaided.
In this episode we speak to Dr Mark Schenk, an aerospace engineer whose childhood interest in origami led to innovative work developing foldable structures.Read more