High Marnham was the most southerly of three power stations which lined the River Trent, known locally as Megawatt Valley, the others being West Burton and Cottam.

[3] The station was constructed by the Central Electricity Generating Board Northern Project Group, on a green field site.

[5] The work was overseen by resident engineer Douglas Derbyshire who later went on to construct the nearby West Burton Power Station.

The plant was designed and built by International Combustion Ltd. Five boiler units, each weighing about 14,000 tons, were suspended on beams and support columns, for a vertical expansion of 8 inches (200 mm).

One furnace carried the superheat pendants, connected to the boiler drum top and to an outlet header, fitted with a safety valve set at 2,450 pounds per square inch (16,900 kPa).

The lower section of the furnace corners contained a wind box with the pulverised fuel nozzles and retractable oil burners.

Fuel nozzles and burners were aligned at an imaginary circle in the furnace ensuring an even heat distribution.

Hot gas was drawn from the furnaces through the pendants, water tube economisers, rotating heat exchanger, cyclone dust collectors and electrostatic precipitators by two induced draught fans before entering the chimney flue ducts and passing up the 500 feet (150 m) high chimneys.

Condensed steam was taken from the turbine condenser and pumped back into the boiler feed system, via the unit evaporator, low and high pressure water tube heaters (after being subjected to bled steam heat from turbine cylinders) into a de-aerator.

At the end of May 1959, the first turbo-generator stator left English Electric at Stafford, for one of the 200 kW 3,000 rpm units.

[9] The annual electricity output of High Marnham was:[9][10] On 15 December 1963, the first 400kV supergrid link in the UK's National Grid was switched on between the power station and the Monk Fryston substation, near the Selby Fork on the A63 road towards Fairburn, North Yorkshire - a distance of 64 miles.

Prior to their closure Thorsby, Welbeck, Ollerton, Bevercotes, Clipstone, Mansfield, Rufford, Blidworth and Bilsthorpe collieries were also connected to the High Marnham Branch.

[13] A pipeline was built to take ash across the Trent five miles to former gravel pits at Besthorpe, Nottinghamshire.