One of the key figures in the construction of LEP passed away on 18 May 2020. Henri Laporte led the civil-engineering work for the Large Electron-Positron Collider in the 1980s, the biggest construction project for fundamental research ever undertaken and which included the construction of the 27 km tunnel that now houses the LHC.

A native of Sète in the south of France, Laporte never lost his melodic accent, which, when combined with his characteristic southern loquaciousness and a talent for storytelling, always brought a smile to the faces of the people with whom he interacted. Laporte graduated from the prestigious French higher education institutes, the Ecole Polytechnique and the Ecole des Ponts et Chaussées, and began his career in marine engineering in the early 1950s. He was appointed as the chief engineer first for the construction of the port of Oran, then for the Toulon naval base, before moving to French Polynesia in 1963 to preside over the extension of the port of Papeete. In 1967, he was recruited by CERN to lead the technical services and buildings division.

Known for his relentless work ethic, his expertise and his authority, he joined the LEP project at the start of the 1980s and was given the responsibility for the hugely ambitious civil-engineering project by Emilio Picasso, the project leader. Before the excavation work could begin, however, CERN had to get the local authorities on board, since the tunnel would pass underneath about ten different Swiss and French communes and nine sites would be built on the surface. Under the leadership of Robert Lévy-Mandel, who was in charge of the impact study, dozens of consultation meetings were held. Laporte shone on these occasions thanks to his oratory and interpersonal skills. During project meetings, Lévy-Mandel and Laporte would indulge in memorable bouts of oratorical sparring, with Latin quotations generously thrown in.

The flagship construction project began in 1983 with the excavation of 18 shafts, followed by the excavation of the tunnel itself. Three tunnel boring machines were required to complete the task of digging out 23 kilometres’ worth of earth under the plain. Explosives were used to excavate the section of the tunnel below the Jura due to fears that a geological incident could halt the progress of the machines. And such an incident did indeed occur in 1986, when high-pressure inflows of water flooded the tunnel, causing delays to the project. Laporte’s expertise and leadership were decisive in the response to this incident and throughout the project as a whole. It was a regular occurrence for him to arrive on site at any time of the day or night to study damage and take urgent decisions. In 1988, the tunnel was finally completed.

But the main tunnel represented less than half of the total excavation work, since the ring is punctuated with access shafts, caverns and service tunnels. In addition, around 80 buildings were built on the surface. Jean-Luc Baldy, who managed the surface work, and Michel Mayoud, who was in charge of the crucial work of the surveyors, remember the trust that Laporte placed in them, giving them considerable room for manoeuvre.

Once the construction work had been completed, CERN became entangled in protracted legal proceedings involving the consortium of companies that had carried out the work. Laporte spent several years working with the Legal Service, once more demonstrating his trademark persistence. At the arbitration tribunal, Laporte distinguished himself not only for his technical knowledge, but also for his talent as an actor and his humour. Eva Gröniger-Voss, the head of CERN’s Legal Service, who was a lawyer on the case at the time, recalls that he would amuse the judges by explaining that, as a bon viveur, he kept hearing “confit d’oie” (goose confit) whenever the lawyers spoke of a “conflit de lois” (legal conflict). Laporte retired in 1993 and devoted himself to numerous intellectual and artistic pursuits for the rest of his life.

Henri Laporte was a man of great curiosity and was highly knowledgeable in many fields. He will be remembered as a charismatic man, with a firm hand and great tenacity, but also someone who exuded a contagious joviality and always showed compassion towards his colleagues.

His friends and former colleagues