The station was later converted to burn supplementary oil over coal, and remained in use until it closed in 1973,[1] by which time its thermal efficiency was just 16.15 per cent.

[2] Two of the turbines were supplied by CA Parsons at 30 MW each driving a directly coupled air cooled alternator running at 3,000 rpm.

In its last years the 1500 4 pole alternator was decoupled from its turbine and used as a synchronous compensator thereby providing voltage regulation to its local grid.

These features became common in later power station designs utilising turbine generators rated at 120 MW and over.

[1] This 'Station was built in response to a rapid demand for electricity as the Country emerged from austerity of the post war years.

The oil-fired International Combustion Limited[3] boilers had an output capacity of 2,520,000 lb/hr (317.5 kg/s) of steam which was delivered to the turbines at 900 psi (62 bar) and 482 °C.

Originally built with three operational units having a design rating of 660 MW MCR (Maximum Continuous Rating), this was increased to 685 MW during commissioning with practically no additional engineering works required which is testament to the robust design standards rigorously upheld by the CEGB.

This resulted in an annual generation of circa 18 000 GWh which may be the unofficial record for the CEGB's 2000 MW class of power station.

Littlebrook D played a vital role in restoring power supplies to the South East of England in the days following the storm force winds of October 1987.

The black-start capability was facilitated by the presence of three GEC Gas Turbine Twin Olympus open-cycle gas turbines (OCGTs), each capable of generating 35 MW, which was sufficient to operate the station auxiliary equipment and allow a main unit to be started.

Each OCGT set incorporated two Rolls-Royce Olympus jet engines which are industrial derivatives of those that were used on the Concorde aircraft.

As well as providing black-start supplies to the station, the fact that they could synchronise and ramp up to full load in under five minutes means they were used to generate at the request of National Grid Company (who operated the UK electricity grid system) to deal with short-term peaks in demand.

Such peaks typically arise during the winter months, where evening demand is higher due to lighting and heating requirements.

The National Grid Company are obliged to ensure that there is enough operating reserve available at all times and as such, low frequency events are rare and will only arise where a substantial loss of generation has occurred.