After a serious accident during a test drive on 30 November 1876, it was decided not to use the roller wheel system and to operate the track as a pure adhesion railway.

Finance for electrification was not secured for a long time, but it was eventually approved at the General Meeting on 6 July 1938.

Electrical operations should have been started on the entire network of the Südostbahn at the timetable change on 15 May 1939.

Since 2018, all rolling stock up to and including class D4 (22.5 t or 22.1 long tons or 24.8 short tons axle load, 8 t/m or 7.2 long ton/yd or 8.1 short ton/yd linear load) has been allowed on the line.

Immediately afterwards, the 5.0% grade begins and the line runs along the slope in a south-easterly direction around the hill on which the ruins of Alt Wädenswil Castle stand.

Next to the line on the right is the Samstagern workshop and the station building with a goods shed and a loading ramp is to the left.

After a good two kilometres, the line reaches the Neuberg crossing loop, which lies to the east-northeast.

Until 1936, the Rabennest tunnel was located at the last turn before the line runs continuously to the south.

Shortly afterwards, the line reaches the storage sidings and Einsiedeln station a kilometre later.

After the train arrived in Schindellegi, the helical wheel which engaged on the track sections disengaged due to irregularities.

It is believed that oil leaked and fell the on the rails and the wheels, rendering the brakes ineffective.

At the entrance to Wädenswil station, the train had a speed of an estimated 120 kilometers per hour.

The Swiss Northeastern Railway (Nordostbahn) withdrew from its construction obligations as a result of the accident, as it seriously doubted the appropriateness of the Wetli system and, as a consequence, did not want to carry out any further tests.

On 26 July 1947, there was a head-on collision of two trains at the Bennau footbridge between Biberbrugg and Einsiedeln.

On 22 February 1948, a sports special train from Sattel to Zurich overran a buffer stop in Wädenswil station at 60 km/h after an error by the locomotive driver, who left the regenerative brake in the "power" position rather than the "braking" setting, and ran into the operating and administrative building of a fruit and wine cooperative.