They are called Gang Operated as they are operated in a Gang, all three switches together, using a single mechanism. They are also called air-break switches as they use air as the breaking medium or G.O.D.(Gang operated Disconnector) switch.
These switches do not have any load-breaking capacity. They can only be operated when the transformer is on no-load and only the small magnetizing current flows through them. A substation must be disconnected from the load it is feed and only then can these switches located on the incoming lines of the substation be disconnected.
These switches are used in lines with voltages about 5 kV. They can also be motorized and operated remotely. Gang operated switches can be mounted vertically or horizontally.
A thin film of non-oxide grease is usually applied to the contacts of the Gang operated switches. The Gang operated switches should be checked periodically for proper alignment and rigidity.