This is Aemsigen, the main passing siding between summit and base. Cars on the right are travelling upgrade. Cars on the left travel downgrade. This is apparent because the cars on the left have their pantographs retracted. Their motor/generators are in the generator mode to produce dynamic braking during the descent. Power generated is dissipated through resistors as heat but I have been unable to determine where the resistor grids are located. The logical location would be the roof but there doesn't appear to be room in the photos. Can anyone help?