Geoff Tappern, Senior Installation Project Engineer at ATLAS, retired at the end of December, over thirty years after his first visit to CERN. “I came here in 1971 from Rutherford,” he says. “We were designing part of an experiment with Alan Astbury. Back then nuclear physics was still a bit of an unknown science. Cryogenics – I couldn’t even spell the word!”

Geoff has been coming back to CERN on a regular basis ever since, working on EMC, Aleph and now ATLAS. During his career he has also worked with Desy, Stanford and the Super Collider. A lot has changed over the years. "We're in a different phase, he says. "The experiments like Atlas are so expensive and large that it must have been 20 years ago that some of these detectors were designed.”

Instead, the emphasis during the construction of ATLAS has been on organising the installation process, says Geoff. “We have had some little problems but nothing too serious,” he says. “That’s remarkable, especially when you take into account that the clearances are very small for the size of some components.” For the larger components of the ATLAS detector, such as the barrel toroid, there were clearances of just 150 mm between the component and the access shaft walls. “That might sound a lot, but remember we’re dealing with something 25 metres long, and we’re handling it on a crane rope 80 metres long.”

The installation of the barrel toroid gave Geoff a heart-stopping moment, he remembers. “We had the Discovery Channel here filming. We’d taken the barrel toroid across the shaft, it was at an angle, and it was probably five metres down the shaft then there was this large ‘Bang!’ and the crane stopped. And you get this guy with a microphone from the film crew who comes up and says ‘Why do you think that happened then?’ And I forget the exact words I used, but it was something like: ‘Basically, it happened because you’re here!’ But we actually got out of that situation very well.”

After that kind of stress, Geoff is now ready to enjoy his retirement. “I’m looking forward to a break. It will be nice to not have the pressure. I prefer an engineering structure. I’ll come back obviously; I’ll still have access to the site. But you have to move on and let go.”

Does he regret retiring before construction on ATLAS is completed? “In a way, yes. You keep thinking it’ll be ready in the next month or so. When I was coming up to 65 it looked like I was going to see the end of it. Now that’s not quite going to happen. But I’ll probably come in to see how things are going from time to time.”

Retirement will give Geoff the opportunity to devote more time to his hobbies. “I collect Roman and Celtic coins from the UK. Of course this is a very Roman area too – there’s a lot of Roman history in Geneva. And I collect early British postage history right back from the 1600s,” he says. “I’d like to do a lot more walking too, now that I have more time.”