But it didn’t take long for him to miss the familiar workshop air, and so Marschall returned to his role as an honorary guide. At that point in his 30-year career at the Visitor Service, he had already taken around 300,000 visitors on tours of the plant – and always on foot. One tour is around three kilometers long. He’s never stopped to think about how many pairs of shoes he must have gone through. In his past eight years as honorary guide, he’s added another 50,000 or so visitors to his tally.