Greenhouse gas emissions at Britain’s biggest container port have been cut more by than 24% in six years, according to its latest environmental analysis.

Previous measurements taken around the edge of the port had shown higher than acceptable pollution levels, but the drive for green energy and lower carbon levels has seen a big drop in emissions – and the port says it is aiming to do even more.

It has invested millions of pounds in environmentally-friendly machinery to cut carbon and other emissions, encouraged its workforce to adopt green attitudes and practices, while the massive ships berthing along its quays have also become greener machines.

Its latest environment report says the amount of CO2 generated per standarde-sized container handled has fallen by 26.4% compared with figures in 2008/09 when measurements were first taken.

Alan Tinline, the port’s environment manager, said: “We are moving a lot more containers for less energy.

“In 2008/09, the relative carbon footprint was 13.1 kg of CO2 per teu, while in 2014-15, the figure was 9.7 kg.

“Our performance continues to improve and we are working to achieve 30% down from 2008/09.”

The report highlights how investment in cleaner technologies and effective traffic management has improved air quality – with nitrogen dioxide concentrations reduced by 20% since monitoring began in 2007, and sulphur dioxide down by 80% since 2009.

Projects which have helped cut emissions include the current programme to convert 54 rubber-tyred gantry (RTG) cranes from diesel to electric.

Mr Tinline said: “We are one year into this project, which will take between two and three years in all and represents an investment of £18million.

“Once we have switched all of the RTGs, we will see a 30% reduction in diesel use at the port.

“The project will deliver many benefits – energy saving, emissions reduction, noise reduction and more efficient operation, too, because the auto-steer feature we are installing will help the drivers.”

Meanwhile, lighting across the port – offices and warehouses have been done, and cranes, masts and towers are next – is being switched to LED to cut electricity usage, and a record recycling rate of 82.5% has been achieved.