Showing their desire for technological innovation and design, the challenge of breaking the speed record on a salt lake arose. Images Team New Zealand
Last February, the New Zealand America’s Cup team announced a project to break the world land speed record using wind propulsion. The idea arose several years ago out of the mutual interest of Glenn Ashby and Grant Dalton, who share a love of motorsport. After having everything planned, TNZ took advantage of the impasse between the end of the America’s Cup’s previous edition and the start of the upcoming 37th edition to be held in Barcelona.
The challenge is to beat the current record held by Richard Jenkins, who set it in 2009 racing 202.9 km/h on California’s Ivanpah Salt Lake near Las Vegas. Jenkins conceived a new “vehicle” concept with a small wing arranged vertically in the form of a self-righting weather vane, with an aileron at the rear for trimming.
All areas of the powerful New Zealand design team got down to work, and quickly decided to follow the same concept as Jenkins, knowing that their technological potential would allow them to design and create a higher performance vehicle.
After construction was completed, the newly-christened Horonuku began long test sessions at the New Zealand military air base Whenuapai, close to the team’s Auckland facility. There, they first confirmed the solidity and strength of the various parts of the vehicle, and then focused on fine-tuning and optimisation. After several weeks of testing, they decided to trim a metre off the fuselage at the rear in order to concentrate the vane’s load centres, centre of gravity and lateral thrust as much as possible.
The vehicle has a long, narrow fuselage, with the pilot’s compartment in the centre, one wheel at the front and another at the rear. To prevent heeling and capsizing, it has a side arm with a wheel at its end, and the cockpit is also ballasted to help reduce heeling.
All controls and commands must be mechanical and human-operated, including when starting the vehicle. Due to the small surface area of the wing, just 10 square metres to minimise drag at high speed, the vehicle requires a manual push to start it and create its own apparent wind to slowly accelerate.
One of the big challenges for TNZ in this project has been to tackle the unfamiliar world of tyres. Experts in hydrodynamic resistance of foils, rudders and hulls, the tasks of tyre tread friction and their subsequent load forces proved to be somewhat new. The equation to be solved is to find the balance between the least friction on the surface, a suitable hardness to function on the “track” of dry salt crystals, and to avoid lateral deformations due to all the load forces bearing down on the three wheels.
With everything tested, the team made good use of its logistical expertise and ingenuity to travel to Australia. All the material, including the vehicle, was loaded into several containers. The Horonuku completely disassembles into parts, capable of being loaded on a special trailer, which is pulled by a vehicle and can be towed on the road.
One of the unforeseen events that has held Glen Ashby and the record-breaking project in check has been the conditions at Gairdner Lake. Team New Zealand’s chosen venue had been flooded with 10 centimetres of water several months ago. The water has been gradually evaporating, and they are confident that it will be dry by the dates initially planned for their attempt and the surface salt layer will have reached the appropriate hardness.
The wind-powered land speed record is certified under the supervision and regulations of the NALSA (North American Land-Speed Association), which certifies the measurements by ensuring that the course does not exceed a drop of one metre. The record must exceed the previous mark by more than 1.6 km/h for a period of at least three seconds.