Diesel Train Emissions and Air Quality in London Paddington Station

U. Chong, J.J. Swanson & A.M. Boies

Department of Engineering, University of Cambridge, CB2 1PZ, UK

Summary We present results from a measurement campaign conducted in London’s Paddington Station with the following objectives: (1) to quantify the air quality in London Paddington station, (2) to compare results to EU regulations and typical London roadside concentrations, and (3) to use modelled train emissions estimates to simulate Paddington particle concentrations with a mixed-box model. Experimental and modelling results can be used to estimate the emissions impact of future train technologies in Paddington and may be useful in guiding transportation technology adoption decisions.

Introduction

The EU and UK government regulate CO, HC, NOx, and PM emissions from new rail cars and locomotives as well as the sulfur content of diesel fuels (1, 2). These regulations could have an impact on London Paddington Station (the 8th busiest train station in Great Britain) (3). Seventy percent train journeys in Paddington are diesel powered and it is the terminus of the Great Western Main Line, which is the UK’s longest non-electrified train line (4). This study aims to quantify air quality and emissions in Paddington to understand the impact of these regulations and potential of emissions abatement technologies used to meet these and future regulations.

Experimental PM2.5 mass was measured at 5 locations using TSI AM510 monitors. Particle size distributions and number concentrations were measured at 2 locations using a TSI CPC and SMPS. Measurements were taken with and without a catalytic stripper to quantify the semi-volatile content of PM. Air samples were also collected on filters for analysis of metals, ions, and elemental/organic carbon (EC/OC) particle composition. Real time measurements of CO2, NOx, and SO2 were also measured at the same 2 locations. Using anemometers, wind speed and direction data were collected at the 2 largest openings into the station so that a simplified mixed box model of particle concentrations in the station could be derived.

Results Reported results include total particle number, mass, and size distribution for the locations shown in Fig. 1. Generally, results showed that respirable PM concentrations in the station were similar to concentrations on a typical London roadside (Marylebone Road). However, during some peak rush hours, concentrations of PM2.5 and NO2 exceeded outdoor EU limits. EC/OC measurements shown in Fig. 2 indicated that the organic fraction of PM depended on the location in the station with highest concentrations near Praed Ramp, furthest from the trains. Similar conclusions drawn from concentration metrics are also discussed in the presentation.

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Fig. 1: Measurement locations Fig. 2: Location-averaged EC/OC fraction. .

References 1. EU (2004) Directive 2004/26/EC of the European Parliament and of the Council. Official Journal of the European Union L-146. 2. EU (2009) Directive 2009/30/EC of the European Parliament and of the Council. Official Journal of the European Union L-140. 3. ORR (2010) 2009-2010 Station Usage Report and Data. UK Office of Rail Regulation. 4. DfT (2009) Britain’s Transport Infrastructure. UK Department for Transport.