The Criminal Trial Surrounding Ayrton Senna’s Death in the 1994 San Marino Grand Prix

The tragic deaths of Roland Ratzenberger and Ayrton Senna during the 1994 San Marino Grand Prix weekend shook the world and put Formula 1 under intense scrutiny. While Ratzenberger’s accident was caused by front-wing failure, Senna’s death became the subject of frenzied speculation.

The Investigation into Ayrton Senna’s Steering Column Failure

As the FIA sought to find lessons from the fatalities that could be translated into effective safety improvements, the Italian legal machine swung into action, and a criminal trial ensued. Public prosecutor Maurizio Passerini’s case focused on establishing that a shear in Senna’s steering column caused his crash at the Tamburello corner.

To investigate this claim, Professor Enrico Lorenzini, Dean of the Faculty of Engineering at the University of Bologna, was appointed as an expert. The steering column was analyzed by two teams of specialists from different institutions to compare and correlate their findings. One part of the investigation was entrusted to the Air Force’s Research and Experimentation Division, based in Pratica di Mare, near Lazio, and the other to the Metallurgy Laboratory of Industrial Chemistry at the University of Bologna.

Thirty years later, Motorsport.com managed to contact Gian Paolo Cammarota and Angelo Casagrande, the two professors from the University of Bologna who performed the analyses. They have remained friends and still occasionally see each other.

The Analysis of Ayrton Senna’s Steering Column

Cammarota, born in 1936 in Milan, now retired, divides his time between Bologna, Venice, and Germany. A slender, reserved man, he weighs every word carefully. While Cammarota’s speciality was Industrial Chemistry, Casagrande, a Bolognese, is still part of the teaching staff in the Faculty of Metallurgy.

In the original design of the Williams FW16, the steering column was a single-piece metal tube measuring 910.2mm in length. To accommodate Senna’s wishes, Adrian Newey – then ’ chief designer – directed the drawing office to lower the steering column by 2mm. When this was found to snag the FIA template, the next best solution was to reduce the diameter of the column by 4mm in that area.

The Findings of the Analysis

Cammarota and Casagrande carried out a series of tests on the steering column, including metallographic analysis, internal and external roughness tests, and fractographic examination. Their expert report submitted to the court read that the three-piece steering column was indicative of a poorly designed modification, as the thinness of the section precisely at the point of maximum stress, the abrupt change in cross-section with an excessively small fillet radius, and the scratches caused by the mechanical processes of drilling and turning all contributed to creating a structurally critical situation.

The modified column was divided into three parts, two made of T45 steel, with external diameters of 22.225mm and a wall thickness of 0.9mm, with an intermediate section of EN14 steel 18mm in external diameter and a wall thickness of 1.2mm. These parts were welded together.

The Impact of the Findings on Formula 1 Safety Measures

The lessons learned from Imola not only informed the FIA’s ongoing safety project but also affected the process of car design in Formula 1. Williams, for example, brought in a system whereby safety-critical components could be signed off for production only after the designs had been counter-signed by an experienced stress engineer.

Regardless of whether that steering column caused the accident or not, it was a bad piece of design that should never have been allowed to get on the car, according to Adrian Newey in his autobiography. The criminal trial was wide-ranging, accusing Frank Williams, Patrick Head, and Adrian Newey of manslaughter, and FIA official Roland Bruynseraede, race organizer Federico Bendinelli, and Imola track manager Giorgio Poggi of culpable homicide. As it progressed, Passerini moved to drop the charges against , Bruynseraede, Bendinelli, and Poggi, focusing his attentions on Head and Newey.