The first project to build the line was proposed in 1873, suggesting a and 25% maximal gradient. It was concluded that the project was not economically viable. Eduard Locher, an engineer with great practical experience, then proposed an alternative project with the maximum grade increased to 48%, cutting the distance in half. Conventional systems at the time could not negotiate such gradients because the cogwheel that is pressed to the rack from above may, under higher gradients, jump out of engagement with the rack, eliminating the train's driving and braking power. Instead, Locher placed a horizontal double rack between the two rails with the rack teeth facing each side. This was engaged by two flanged cogwheels mounted on vertical shafts underneath the car.