Whether you like it or not, Halo will make its full Formula One debut when pre-season testing kicks off in Barcelona on February 26. By that time we'll have seen how the teams have factored Halo in to their 2018 car designs and open-cockpit racing in F1, as we knew it, will be a thing of the past. Below are the key facts you need to know about one of 2018's biggest talking points.
What is it?
The Halo is a titanium structure that sits above the car's cockpit to protect the driver's head from flying debris. A single vertical pylon supports the structure in front of the driver and the hoop above the cockpit is mounted to the car's survival cell and cockpit surround. The device will be mandatory on all cars this season.
Who came up with idea?
After several years of FIA research into the safety benefits of front roll structures on single seaters, Mercedes proposed the Halo concept in 2015. The first Halo prototype -- made of steel -- underwent static tests at RAF Bentwaters in 2015 and performed well against a 20 kg tyre fired from a nitrogen-powered cannon at speeds of 225 km/h. A steel prototype shrouded in carbon fibre was track tested by Ferrari during winter testing in 2016, with drivers reporting acceptable levels of visibility despite the vertical pylon directly ahead of the cockpit and the large protective section above.
At the 2016 Austrian Grand Prix, a lighter, stronger prototype made of titanium was introduced. One of the notable changes was making the arc of the Halo wider in order to improve visibility and eradicate the risk of a driver hitting his head on the structure during an impact. Extrication tests took place in the pit lane before it was run on track at the following round in Silverstone. A series of tests followed during Friday practice sessions in 2016 and 2017 before a final design was decided upon and made mandatory for 2018 midway through 2017.
How much safer is F1 with Halo?
In 17 case studies of serious accidents carried out by the FIA, Halo would have resulted in a beneficial outcome in 15 while the other two would have proved neutral. The structure is designed to stop cockpit intrusion from large objects, such as wheels, another car or trackside barriers. However, it would not have made a difference in Jules Bianchi's collision with a heavy-duty track vehicle at the 2014 Japanese Grand Prix, which left the Frenchman with head injuries that ultimately proved fatal.
It is also hard to assess the impact it would have had on Felipe Massa's freak accident at the Hungarian Grand Prix, when a spring came loose from Rubens Barrichello's car and struck the Ferrari driver on the head. But in FIA studies of small objects being projected at the Halo from different angles, it was found that the structure would protect the driver 17 percent of the time -- as opposed to zero percent of the time without the Halo.
How strong is it?
New crash tests have been introduced in 2017 that are specifically designed to ensure the Halo is strong enough. Although the structure itself is built by an FIA-approved supplier, the mountings to the chassis are the teams' responsibility and they are the main focus of the crash tests. The biggest load applied to the structure is from above and amounts to 116 kiloNewtons of force.
The peak load has to be withstood for five seconds without a failure to any part of the survival cell or the mountings. Longitudinal forces of 46 kN and 83 kN have to be withstood from the front as well as a lateral load of 93 kN from the side. For comparison, the roll hoop on top of the car has to withstand 50kN laterally, 60kN longitudinally and 90kN from above.
Will all Halos look the same?
Not exactly the same. While the titanium structure and general shape will be the same, the teams can shroud them in their own carbon fibre fairings. Room for different designs is limited, however, with just 20mm of space for aerodynamicists to play with. During the end-of-season tests in Abu Dhabi last year, a number of teams introduced aerodynamic elements to their Halos, with the aim of re-directing airflow around the car.
Unlike the majority of prototype Halos tested so far, the outside of the structure does not have to be black and the Halo can be painted to fit the livery of each car. It should also provide valuable sponsorship space, which is likely to be exploited by all teams.
Will teams be able to gain a performance advantage from it?
To start with, incorporating Halo into car designs will be about minimising lost performance rather than gaining extra performance. Teams have not reported major challenges from an aerodynamic point of view, apart from the need to redirect airflow for cooling purposes and towards the rear of the car, but putting that much weight that high up is a car designer's nightmare. The Halo and mountings combined are expected to weigh between 10kg and 14kg, with teams looking to minimize the weight of the mountings while still passing the FIA's crash tests.
The minimum weight of the car and driver has been increased by just six kilograms to accommodate Halo, meaning teams are facing a struggle to shed kilos from their designs to accommodate the Halo. For some teams it will result in less ballast to play with around the car, but others may find their driver and car combinations tip the scales above the minimum weight at the start of the season. Don't be surprised to see some of the taller drivers looking super lean in pre-season testing.
Won't it impair the driver's vision?
Despite the bulky look of the Halo, very few drivers have complained about visibility issues during testing. There were fears that circuits with extreme elevation change -- such as Spa-Francorchamps -- might leave the drivers with a blind spot directly ahead when approaching a hill, but when Mercedes' Nico Rosberg drove it at the 2016 Belgian Grand Prix he said it made no difference.
"No problem at all, you don't even notice the top part," Rosberg said. "I think they can even come down with that because LMP1 is lower anyways. So for sure they could go lower." There are still some questions over the positioning of the starting lights on the grid, but the FIA is confident it can find a suitable solution so all drivers get a clear view come lights out in Australia.
Will drivers struggle to climb out of crashed cars?
This was one of the first concerns about adding further cockpit protection, with critics suggesting the Halo would get in the way and create a safety hazard in itself. Under the regulations, the amount of time in which a driver must be able to climb out of the car has increased from five seconds to seven seconds to cater for the added difficulty of navigating the Halo.
With cars rarely catching fire in modern Formula One, it was felt that the additional safety benefits of the Halo outweighed the extra two seconds it takes for a driver to get out of the car. In the unlikely event that an impact is strong enough to deform the Halo, cutting tools will be carried in the F1 medical car to ensure there are no issues getting drivers out of dangerous situations.
After his terrifying barrel-roll accident at the Australian Grand Prix in 2016, Fernando Alonso said a Halo would have been "very welcome" regardless of how long it took him to get out of the car afterwards. A subsequent study by the FIA revealed that the Halo would not have prevented Alonso climbing out and would have created extra "breathing space" for the driver to work his way free from the upturned cockpit.
Is F1 stuck with it forever?
While it is incredibly unlikely that the FIA will remove frontal cockpit protection from Formula One, the design and shape it takes may change. Prior to the final decision to introduce Halo in 2018, the FIA looked at the possibility of a curved windscreen known as the Shield in its place. F1's Strategy Group wanted to throw the sport's full support behind the Shield, but the future of the concept hinged on its first on-track test at the British Grand Prix last year. That test lasted just one lap before Sebastian Vettel returned to the pits complaining of distorted vision, aerodynamic side-effects and dizziness in his Ferrari.
Yet the FIA remains open to evolving the Halo and Formula One's new owners Liberty Media are convinced it can be made to look more appealing. Aesthetics are set to be a cornerstone of the next major regulation change in 2021 and F1 chief Ross Brawn is confident Halo can be built into the design of the cars to make it more visually appealing.
Several concept cars released by manufacturers in recent years have also featured some sort of cockpit protection, usually in the form of a canopy, and Formula E's recently launched Gen2 car does a much better job of incorporating the Halo into the design than the F1 prototype Halos. Ultimately, however, a new form of cockpit protection will have to be safer than the Halo to be considered.