Barriers that can protect drivers in high speed incidents are essential in open wheel racing. With short run-off areas at some corners, especially on traditional circuits such as Monza and Spa, a driver can often find himself hurtling towards a barrier at speeds in excess of 200 kph. For this reason the FIA and the FIA Institute have been focused on developing an ingenious solution – a barrier able to protect drivers in high speed impacts, at even the most constricted of circuits.

This special barrier, which can dissipate energy in a way that minimises injury for the driver, has been over six years in the making. It is set to revolutionise circuit safety. This is because it can absorb the energy of a 187 kph impact in just four metres whilst keeping the g-forces on the driver within acceptable limits.

The accident which triggered this particular research was Michael Schumacher’s crash in the 1999 British Grand Prix at Silverstone. The Ferrari driver left the track after a brake failure at Stowe corner at 204 kph and hit the tyre barrier at 107 kph. Incredibly, apart from a broken leg, the seven-times-world champion had no other injury.

However, FIA safety expert Peter Wright later recognised that Schumacher had a lucky escape. By studying data after the race, Wright found that the driver was particularly fortunate not to suffer any head injuries.

Wright contacted Hubert Gramling, a German engineer and crash-test expert, who had assisted the FIA already in the development of the Head And Neck Support (HANS) system. He asked his colleague to develop a barrier which gives the driver the best chance to survive a high speed crash without any serious head injury. That conversation led to a six-year sequence of calculation, computer simulation, brain-storming and testing in collaboration with German automotive safety group DEKRA, which would culminate in a leap forward for modern motor sport safety.

First, Gramling developed software to simulate the momentum from a crash at any given speed for different types of barriers. Using this programme he examined the crash data from different types of accidents. He found that some drivers had walked away unharmed from high-speed impacts whilst others were injured in seemingly less severe incidents. For instance, at the Spa-Francorchamps circuit in 1999, Jacques Villeneuve hit the tyre barrier at 190 kph and his car was brought to a standstill in 400 milliseconds over a distance of just seven metres. Yet he walked away unharmed. By analysing this data Gramling could develop a model of a barrier which would give the driver the ideal crash momentum.

A computer model was developed which showed the driver’s movement in the car during a heavy impact. Gramling’s first simulation was with a barrier with five separate layers. Using the computer programme he worked out the consequences from all possible combinations. “Within minutes we simulated over five million scenarios,” says Gramling. The research showed that the best solution was to allow the driver a relatively high g-load level - a speed reduction of approximately 40 kph - during the first part of the impact.

The initial part of the impact is not very critical because the driver has some space to move forward before the tightening of the seat belt, which in itself has some elasticity. In this phase the head often hits the steering wheel, where forces need to be reduced. The speed here should not pass five to seven metres per second (m/s). Schumacher for example hit the steering wheel in Silverstone at just 5.8m/s. But had there not been so many rows of tyres at Stowe corner it could have been easily 12m/s. Any speeds above 8m/s can be critical for the driver.

However, not every circuit has so much space available as the run-off area of Stowe corner. So Gramling came up with a theory that could solve this problem. The idea was to manoeuvre the driver in the first part of the accident inside the car to a position where he can sustain high loads in the latter part of the accident. This is what the tyre wall did in the Schumacher accident and explains the relatively small injury in such a major crash.

The car would also transfer the momentum of the first part of the impact onto the second layer of the barrier. Gramling explains: “It is just the same as what happens in a multi-car pile up. The first car gives its energy to the next one and so on”.

A first test was conducted with a 20mm thick conveyor belt placed in front of a tyre wall. However, with an impact speed of 80 kph the belt started to tear. At 100 kph the trolley penetrated the belt. “It was total destruction,” says Gramling. Strengthening the belt did not provide a solution either and, in fact, the barrier became so stiff and heavy it would be impractical for circuit use.

The tests also revealed a problem with the theory. Gramling explains: “The concept of a momentum transfer in two phases could not be made to work without accepting other downsides. What we needed was a consistent deceleration over the whole impact.”

After the tests with the conveyor belts had failed, the FIA received a call from French company TecPro International, which had designed some energy absorbing containers and wanted to work with the FIA on future projects. Gramling saw an opportunity and asked TecPro to donate these elements for testing with a view to future purchase. TecPro agreed.

The TecPro blocks are containers measuring 1.5m long, 1m high and 0.6m deep. Each end is formed like a half circle, enabling them to connect with each other like a jigsaw puzzle. Nylon straps hold them in place.

At the start of the experiment the containers were filled only with polyaethylen foam, a substance known to absorb high energies. Using a trolley with a front nose similar to an open wheel race car, which was specially developed by the FIA Institute, DEKRA commenced the test at its facility in Neumünster. At the first attempt the trolley crashed through the barrier just as it had with the conveyor belts. So to stop penetration, two 2mm steel sheets were placed vertically in the centre of each container with 30cm layers of foam on each side. The overall weight was 140 kg for a container, a feasible amount for two trackside marshals to handle.

The second test, at an airport in Itzehoe, took place with two rows of steel armed blocks. It worked. The trolley crashed into the structure at 127 kph and stopped without any penetration of the barrier material. The driver would have had to sustain only 30g during impact.

As chance would have it, Gramling realised that the data from this test correlated exactly with the data taken from a crash involving Felipe Massa at the Monaco Grand Prix in 2002. The Brazilian, who then drove for Sauber, had hit the tyre wall at Ste. Dévote corner at exactly 139 kph, following a brake failure. Massa also experienced a deceleration of just 30g and was unharmed.

Gramling soon realised that by combining the Ste. Dévote tyre wall with the TecPro barrier he could create the ultimate safety device. But there was still some fine-tuning to be done. The TecPro blocks were followed by four rows of tyres with a gap of 2m in between. In the middle of the tyres, tubes of high density poly-aethylen were inserted. Behind this was a final barrier, which was a special retaining wall supplied by German company Bernd Spengler. With this barrier a 173 kph impact was managed at a deceleration of 65g. A final crash test in 2006 proved to be the culmination of the previous six years work. The trolley was driven at a speed of 187 kph into a barrier made up of only one line of steelarmed TecPro blocks, followed by a 1.2 m gap (shortened to improve efficiency), then six rows of tyres with poly-aethylen inserts and finally a moveable retaining wall. The whole barrier was just four metres deep and the result was stunning. With a deceleration of 55g for the driver, the load was way within acceptable limits.

The accumulated data helped to develop this type of barrier for all kind of corners and run-off areas. As Gramling puts it: “We now know how big the gap between the TecPro blocks and the tyres has to be and how many layers of tyres we need for a given impact speed.“ It all bodes well for the future. Gramling says: “With what we know after all these tests we are confident that the barrier we tested at 187 kph can master a 210-220 kph impact in a limited area.” The research has delivered another positive result. The construction of the TecPro blocks has the added benefit of preventing the car from getting stuck in the tyres because the car carries the blocks with it into the next barrier. This will undoubtedly help safety marshals gain access to the driver immediately after an incident.

The research became reality in September 2006 when the barrier was used for the first time at a Formula One circuit for the Italian Grand Prix in Monza, where it was installed at the end of the run-off areas at the circuit’s second chicane and Parabolica corners. The FIA and the FIA Institute were delighted with the installations at Monza and have begun discussions on the feasibility of similar installations at other tracks around the world. It represents yet another step into a new chapter of safety led by the FIA Institute’s ongoing campaign.

This article was taken from ‘Formula For Safety’, the FIA Institute’s annual review. Click here to download a pdf of the publication.