Gérard Bachy came to CERN in 1967, straight after graduating from ETH Zurich, and spent his entire 35-year career with the Organization.

He started off as a mechanical engineer with the BEBC (Big European Bubble Chamber), where he was in charge of the design and manufacture of the expansion system. The bubble chamber is still on display in the garden of CERN’s Microcosm. In 1972 he joined the team of John Adams that was building CERN’s new flagship facility, the SPS, taking on responsibility for the coordination and installation of the new accelerator. The first protons were injected into the SPS on 3 May 1976. Gérard was then approached by Giorgio Brianti, then deputy head of the SPS division, to set up a section in charge of the UA (Underground Area) infrastructure and the installation of the experiments. He formed a team of motivated people where new ideas thrived and were put into practice. These included a bicycle-driven system for moving detector components weighing several dozen tonnes using air cushions. The conversion of the SPS into a pp-bar collider led to the discovery of the W and Z particles in 1983.

In 1981, when the huge LEP project was taking shape, Gérard and his team were brought in by the Director in charge, Emilio Picasso. The team was soon merged with the Engineering group to become the LEP-IM group, which went on to play a key role in the realisation of LEP. More innovations were to come in order to solve the many challenges associated with this huge project: modular access shafts; a monorail, which facilitated the installation of the various components, even though the civil engineering was not yet complete due to significant delays under the Jura; highly precise planning and logistics, etc. The project advanced at a fast pace, culminating in the start-up of LEP on 14 July 1989.

The engineering for the accelerators was spread across the various CERN divisions, which hampered efficiency. In 1990, Carlo Rubbia, who was Director-General at that time, entrusted Gérard with bringing all the different activities together under one umbrella, and the MT (Mechanical Technologies) division saw the light of day. Over the next five years, the focus was on modernising the facilities, infrastructures and working methods, first for the LEP200 project, then for the preparations for the LHC. Gérard fostered the development of EDMS, the Engineering and Equipment Data Management service, encouraged the creation of quality assurance plans and actively promoted the development of a project management culture.

In 1996, Hans Hoffmann, the technical coordinator for ATLAS, appointed Gérard as project engineer in his technical coordination and integration team. Gérard’s experience was to have a big impact on important technical choices, such as the “large wheel” concept for the ATLAS muon spectrometer.

Gérard retired in June 2001 to be able to devote more time to his other great passions, sailing and travel.

Gérard was a brilliant engineer and a charismatic leader. He played an undisputed role at the top level of engineering at CERN and acted as a mentor for many of us.

We send our heartfelt condolences to his wife, Catherine, their children and all his family.

His friends and former colleagues