After seven years of testing and debate, a head protection system will appear on race cars for the first time in a Formula One race on Sunday at the Australian Grand Prix in Melbourne.
The feature, known as the halo - although the correct technical term is frontal cockpit protection device - is a roll-bar structure with a single central strut, made of titanium and weighing 15.4 pounds.
A driver's head has long been vulnerable in open-wheel racing. The need for better protection became obvious in 2009, when one driver was killed and another injured in separate events a week apart.
Henry Surtees, the son of John Surtees, a Formula One world champion, was killed when an untethered wheel struck him on the helmet during a Formula Two race at the Brands Hatch track in England.
Six days later, during qualifying for the Hungarian Grand Prix, Felipe Massa, then driving for Ferrari, was hit on the helmet by a suspension spring that had fallen off the Brawn GP car of a fellow Brazilian, Rubens Barrichello. Massa, who required a titanium plate in his head, returned to racing the next season.
"When we started the programme in 2011, we looked at a very large variety of solutions to ensure nothing was discounted," Laurent Mekies, safety director at the FIA, the sport's governing body, explained in an interview. Mekies, who is to join Ferrari in September in a technical role, added, "It was an open-minded approach, to look at everything, all possible concepts.
"So we looked at full canopies - a fighter-jet style of the canopy; we looked at a roll bar in front of the drivers, and a partial roll bar just in front of the monocoque.
"Some of these concepts made it to the track. For instance, with the GP2 cars, we used a roll bar in front of the drivers, in order to not only protect them but also assess visibility."
It was determined that a driver needed to be protected from an object as large as a complete wheel assembly, weighing 44 pounds and travelling at 140 mph.
"This was the driving factor of all the concepts," Mekies said. "All our testing was based around that.
"As we progressed the work, what we realised is that in asking for a structure to be as strong as what we were looking for, it had massive benefits in a number of other areas and potential accidents, other than a simple wheel strike," such as car-to-car contact or a car hitting a tyre or concrete wall.
"Having chosen the load, the testing conditions involved a full-scale dynamic test where we projected a wheel assembly at the structure, and observing the behaviour, or not, of that structure, in two respects: Does it fail? And is it able to deflect a wheel away from the driver's head?"
Throughout development, and before making a final decision on which device to use, Mekies and the FIA were aware of the impact the structure would have on the sport.
After its initial introduction at a preseason test in 2016, the halo was almost universally derided, in particular for its aesthetics. So Red Bull developed its own prototype, the aeroscreen, which struggled in tests conducted by the FIA before the team abandoned the idea.
The FIA had planned to introduce the halo for the start of the 2017 season but decided to look at other options, forcing a delay. At last year's British Grand Prix, and after relatively successful tests, a system known as the shield was fitted to the Ferrari of Sebastian Vettel during a practice session. During that short test, it was discovered that the device offered less protection than the halo. So the halo was adopted, but criticism remains. Toto Wolff, the head of the Mercedes team, recently said he was "not impressed with the whole thing."
"If you give me a chain saw, I would take it off," he said. "We need to look after the driver's safety, but what we have implemented is aesthetically not appealing.
"We need to come up with a solution that simply looks better. It's a massive weight on top of the car, and you screw up the centre of gravity massively. As impressive as the statistic is that you could put a bus on top of it, this is a Formula One car."
Mekies said making a decision was not an easy process. "The reason why is because you have many different sensitivities when it comes to how safe the sport needs to be; is the danger part of the thrill of watching it?" he said. "Then there were the aesthetic considerations of bolting a new structure on an open cockpit.
"From an aesthetic point of view, it was something so new - and we didn't target aesthetics then, we targeted function and maximum safety - the initial reaction was very mixed." Whatever the discontent among teams, the halo is now a fixture in Formula One. Although the halo is the first head protection device approved by the FIA, it is unlikely to be the last.
