Did you know that 50 micrometers can make a crucial difference on the way to the summit?

© Doppelmayr Seilbahnen GmbH

Did You Know…

…that 50 Micrometers Can Make a Crucial Difference on the Way to the Summit?


Cable cars and ski lifts carry thousands of people up to the summits or back and forth between ski resorts day in and day out, especially during the winter. Passenger safety is a top priority. This is why the production of all cable car parts depends on maximum precision down to hundredths of a millimeter. The drive pulleys that move the cable between the top and bottom stations are huge, and the center part alone weighs just under two tons. This central piece is surrounded by four wing elements.

Absolute precision is mandatory when manufacturing these parts so that the adapter plates of the wing elements can be connected seamlessly to the center part. In the case of a pulley with a diameter of five to seven meters, precision means that the working surfaces may only deviate from the ideal shape by a maximum of 50 micrometers. If the distance between them is any greater, the wing elements will no longer be able to close. These extremely low deviation tolerances demand comprehensive and extremely reliable quality assurance.

Cable car manufacturer Doppelmayr ensures the quality of its systems by using a bridge-type coordinate measuring machine from ZEISS. that scans the center part of the pulley in one complete CNC cycle. When doing so, it compares actual and target states, thereby detecting even the tiniest deviation. The results of the measurement can be retrieved at the touch of a button.

This enables the quality assurance process to be carried out much more quickly. In the past, quality was literally inspected by hand: A specialist would use a measuring arm to measure all relevant parts of each individual component. With the measuring machine, the process is not only shorter, but also four to five times more precise. Thus, the cable car manufacturer can guarantee the safety of his passengers – and they can focus on enjoying the view of the mountain from the cable car as they make their way to the summit.

30 October 2012