Tideway’s extensive use of the river to transport construction materials has dramatically reduced the impact of the project’s vital work on London’s air quality, new research shows.

The studies, commissioned by the company building London’s new super sewer, demonstrate that Tideway’s tugs and barges produce far fewer emissions than the road equivalent.

One of the largest 1,600-tonne barges, for example, can carry as much material as almost 100 lorries. This has obvious benefits for cyclists, pedestrians and other road-users.

But beyond that, the new data shows that Tideway’s use of the river has dramatic effects on the impact of its work on air quality.

Compared to modern standard Euro VI HGVs carrying the equivalent cargo, a 75 per cent engine load 1,000-tonne barge will produce:

• 90 per cent less CO2 (carbon dioxide)
• 95 per cent less CO (carbon monoxide)
• 86 per cent less NO (nitric oxide)
• 54 per cent less NOx (nitrogen oxides)

The air quality benefits of using tugs and barges (instead of lorries) increases when larger barges are used. Tideway has a number of barges ranging from between 800 and 1,600 tonnes.

Roger Bailey, Tideway’s Chief Technical Officer, said: “Tideway’s use of the river to transport materials is on a scale unprecedented in modern times. While our ultimate goal is to clean up the River Thames, we’re also committed to boosting the river economy, increasing jobs and improving safety standards.

“By transporting at least 95 per cent of our tunnelling waste by river instead of on the road, we’ll significantly reduce our carbon footprint, as well as reduce road safety risks in London. We are confident our work will lead the way in how businesses in future consider sustainable options for transporting goods and materials.”

Research into the dispersion of the emissions from the tugs was also analysed to measure the extent of its impact. A comparison of the average tug emission rate with the emission rate from 50 HGVs travelling at 20km/h found the lorries to be 2.3 times higher.

The study found that average emissions from tug ‘Felix’ contributed less than 0.13 µg/m3 to concentrations of nitrogen dioxide, even at locations very close to the tug.

Compared to the European standard for nitrogen dioxide levels (40 µg/m3), this is a negligible amount.

And, given that the tugs will generally travel at distances greater than 50m from bank of the Thames (and therefore from the closest receptors) the contribution to nitrogen dioxide concentrations from tug emissions at this distance is just 0.01 µg/m3.

Daniel Marsh, from Kings College London’s Environmental Research Group, which provides air quality information and research in the UK, said: “London is currently seeing large areas of urban regeneration coupled with major infrastructure projects and the supply chain for all this construction activity puts huge pressure on a road system that was already struggling to cope.

“Construction traffic not only adds to congestion, it poses a risk to the safety of other road users and pedestrians and can have a significant impact on local air quality. Tideway is leading the way by using the river to transport materials and have reduced their on-road freight requirement by 72 per cent and reduced the exposure risk from harmful pollutants for thousands of Londoners.”

Tideway is currently working with a number of organisations to trial various new technologies to the marine sector which will hopefully reduce its impact even further.

In addition, Tideway is working closely with the Mayor of London and the Port of London Authority to reduce emissions throughout the marine sector.