The styling of the Halo device might not be to everyone’s tastes, but there’s no doubt that it’s strong. Incredibly strong. Support the weight of a double-decker bus strong (or, should you prefer, two elephants strong). It has to be.
To pass its structural test, the 7kg titanium device has to withstand 125kN of force (equivalent to 12 tonnes in weight) from above for 5sec. Why so strong? So that it can stop a 20kg Formula 1 wheel, travelling at 140mph, from hitting a driver. Preventing such incidents has been a target of the FIA, motorsport’s governing body, since 2009, when Henry Surtees was killed in a Formula 2 race after being hit by a wheel and F1 star Felipe Massa was seriously injured after a suspension spring struck his helmet.
“We explored a number of different options,” says research engineer Andy Mellor, a consultant to the Global Institute for Motor Sport Safety, the FIA’s safety partner. “The challenge is that the position you need to put such a protective device in is also a position where the driver needs to see. So either you go for a transparent solution, which you can see through and does a structural job, or you go for a structural, non-transparent solution – but which can’t interfere with the driver’s ability to see.”
Various solutions, including transparent screens called the Aeroscreen and Shield, have been tested on crash rigs and on track during grand prix practice sessions. But there were ongoing visibility issues and other concerns about such devices, and other benefits of the Halo meant it became the clear choice. Crucially, recreations of various incidents, such as Fernando Alonso’s roll in the 2016 Australian Grand Prix, failed to find any situations in which the Halo significantly reduced safety.
“We had to look at how strong the chassis needed to be to support the Halo structure, so that it can do the job it needs to do,” says Mellor. “That load is similar to the loads for the principal roll structure on an F1 car, so the two were integrated, and Halo is now the secondary, forward roll structure on the car, and the test loads on it are higher than for the principal roll structure. So in addition to deflecting debris, the Halo is a very protective part of the car for dealing with incidents such as rollovers.