The nitrogen production plants can also be turned on or off in minutes to operate during times when utilities are experiencing reduced demand.

The dam is only required to operate during times of extreme drought.

At the same time, no democracy can operate without a degree of secrecy, during times of peace as well as war.

The 991A is operated by both companies at irregular frequencies during peak times, in both directions.

In general, selection operates most powerfully during times of famine or other privation.

Interestingly, the series depicts them operating as normal trains during times of peace.

Peaking power plants operate only during times of peak demand.

Normally operated by a three carriage set but during times of high demand these can be built up to four.

A route in orange on here means that it only operates during certain times, such as evenings or weekends only.

In 1951 4 trams per hour operated over the line during peak times.