The High Speed Quad
Here is a short explanation of how a high-speed detachable
ski lift works.

The lift pictured below is the Thunderhead Express in
Steamboat, Colorado.

It was built by:
This page is a flow chart of how a high-speed quad terminal
works.  Follow down and click pictures for larger views.
The chair rounds the station.
A chair going down the line to the
Here are the black wheels talked about
earlier.  They provide the motion for the
chair when it isn't on the cable.  Notice
the derailer is in the down position.
The chair enters the derailer.  Notice
how the black arm stabilizes the chair.
The black metal strip derails the chair
while the black wheels slow down the
chair until the unloading speed is
Sensors ensure that the grip is properly
attached on the cable.
A chair in the base terminal slowed
down to the loading speed.
Here are brittle bars or sensors that
would stop the lift in the event of a
If a chair needs to be repaired it can be
removed here and left on this rail.
And off goes the chair!
Doppelmayr chairs consist of two
major parts connected where the chair
number is located above.
Doppelmayr high-speed lift
Left: This is the chair that
maintenance employees
use to work on the lift
towers and sheaves.

Right: The old Doppelmayr
high-speed grip.
High-speed lifts are sometimes built with rails (shown in the picture to the top right) so
the chairs can be removed in the summer or for maintenance.
Here is a quad chair with covers.
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The chair begins to accelerate to leave
the terminal.