While the bottom of the valley is still covered in shadows, the west-side is bathing in sunlight. The town of Wassen seems to be strategically located, getting sun early during the day.
Train 67767 connects Hüntwagen-Wil with Sigirino – minutes before this sunny photo was taken, it was still riding in the dark part of the valley. These trains transporting gravel (I guess) were a common sight on the Gotthard railway. You could even see several ones per day. Today, they ride through the new base tunnel, too.