I had it wrong on my previous post. The train runs fron Brig Switzerland to Iselle Italy. I've copied a bit of wikipedia info below;
Car-carrying shuttle trains
There is a car-carrying shuttle between Brig and Iselle di Trasquera which provides a 20 minute train journey as an alternative to driving over the Simplon Pass. The service began on 1 December 1959. As roads over the Simplon Pass steadily improved throughout the 1970s and 1980s the tunnel's shuttle schedule was cut back, then ended altogether on 3 January 1993. Almost twelve years later, on 12 December 2004, the car shuttle service began again and now runs about every 90 minutes.