Only as a last resort (Power Emergency) to avoid the risk of a complete blackout does ERCOT ask utilities to reduce demand by dropping load through rotating outages.

FORBES: Lights Dimming in Texas; Rolling Blackouts Likely

Warnings are issued by ERCOT when there is a high risk that rotating outages will be needed to reduce load.

FORBES: Lights Dimming in Texas; Rolling Blackouts Likely

Being simply a rotating horizontal shaft with a heavy vertical load on it, early locomotive axles suffered severe stress reversals in their outer skins with every rotation.

ECONOMIST: Aircraft fatigue

For example, the vector-based maps load quickly and allow for smooth tilting and rotating of 2D and 3D views.

FORBES: Google Maps App Comes To iOS 6