In addition to measuring emissions of road vehicles such as trucks, vans and passenger cars, TNO is committed to measuring the real-world emissions of other vehicles and mobile machinery.
Excavators, tractors, generators, inland vessels and train locomotives fall within the scope of NRMM (Non-Road Mobile Machinery) emission legislation. Up to now, real-world emissions of this category are poorly known. Over the past couple of years, however, TNO has also been monitoring various inland vessels, trains, and construction machines using the Smart Emission Measurement System (SEMS).
During this monitoring peculiar emissions were observed, especially with diesel locomotive and with heavy machinery. For example with diesel locomotives, that are primarily concerned with shunting, the engines are idling for 80% to 90% of the time. During this idling, the NOx emissions are often much higher than during load conditions which are covered in the official test procedure. In these instances, fuel consumption is relatively low. In several cases, it is observed that half of the harmful emissions occur during idling and during very low engine load conditions. For fuel consumption this applies to a lesser extent. Still, a mere 10%-20% of fuel savings can be achieved when the engine is switched off during (long) idling periods.
Inland vessel and train engines roughly compare in engine size and yearly engine work performed to 3 to 6 truck engines. The emissions of current trains, inland vessels and construction machinery are disproportionally high compared to those of modern trucks.
Compared to the heavy-duty and light-duty emission legislation for road vehicles, the current Stage-IV emission legislation for non-road mobile machinery is lagging years behind. Often, emissions in normal use, are many times higher than prescribed by legislation. The emission limits themselves constitute only a fraction of the problem. TNO’s monitoring programs show that the formal monitoring test procedure for determining the emissions of NRMM, only partially covers these real-world usage for this type of machinery.
Based on this monitoring programme TNO observes the following:
Below, you can download relevant reports and presentations on measuring the emissions of non-road mobile machinery. Furthermore, you find links to related webpages on emission measurement.