Locomotive Emissions Monitoring Program - Railway Association of ...

7.2.6
Low and Ultra-Low Sulphur Diesel Fuel
Sulphur in diesel fuel influences emissions both directly in the amount of SOx produced and indirectly by enabling
exhaust emissions reduction technologies such as diesel particulate filters and oxidation catalysts to function and
not become contaminated 18 .
In harmony with standards introduced in the U.S.A., as of June 2007 Canadian refineries are required to limit
diesel fuel sulphur content to a maximum of 500 ppm (0.05 per cent), referred to a low sulphur diesel fuel. As of
2012, ultra-low sulphur diesel fuel (ULSF) having a sulphur content limited to 15 ppm (0.0015 per cent) will be the
only diesel fuel marketed in Canada available to the railways. In view of the environmental benefits of ULSF, VIA Rail
Canada and the commuter passenger railways standardized on its use.
7.2.7
Freight Car Technology Improvements
The maximum allowable axle load has been increased from 119,545 to 130,000 kg (263,000 to 286,000 lbs) on many
lines in Canada. This means the needed gross tonne-kilometres of train consist to move a given amount of freight
is reduced. The gross-to-tare ratio of such freight cars is increased permitting the railways to reduce the number
of railcars without losing capacity. Similarly, to improve gross-to-tare weight ratios, the railways have invested in
lighter-weight aluminum railcars. Also, freight car rolling friction has been reduced through the use of steerableaxle
trucks and the universal use of roller bearings on running gear. 9
Double-stack container cars permit a higher container cargo volume for a specific train length, thus lowering the
fuel consumption and emissions per RTK of intermodal trains. However, on intermodal trains attention is required to
avoid unfilled slots, that is, flat cars without containers. Analyses have shown that improving slot utilization from
90 to 100 per cent reduced the aerodynamic resistance coefficient sufficient to save up to 2.4 L/km of fuel 19 .
7.2.8
Longer Trains
Trains up to 2.5 kilometres in length are now operating as a result of lengthened passing tracks and sidings. Longer
trains permit improved utilization of the locomotive power. In its long trains, CN is deploying Distributed Braking
Cars (DBC) which are placed at the end of trains to maintain airbrake pipe pressure at a certain operational level.
The DBC were developed to assist in the operation of long trains in cold weather conditions, particularly between
Winnipeg and Edmonton. The concept is based on the older-design air repeater car, which utilized an air compressor
installed in a box car that was placed in the middle of the train. DBC obviate the need for additional locomotives used
primarily in long trains to supply additional air for the braking system and, hence, avoiding the concomitant fuel
consumption and emissions. DBC are monitored by a suite of proprietary Wi-Tronix software that link CN managers via
the internet to provide data on: GPS tracking, fuel levels, refuel alerts, engine monitoring (running state, overload,
oil temperature, and coolant temperature), main reservoir pressure, battery voltage monitoring and the ability to
receive E-mailed alerts 20 .
7.2.9
Remote Power
Distributing a remote-controlled locomotive within a freight train permits better handling of long trains, especially
in undulating terrain, so as to provide more optimum locomotive power assignment and better air distribution for
braking. As well, distributing a locomotive within the train helps remove energy-dissipating slack action.
18 Operational Effects of Low Sulfur Diesel Fuel in Locomotives, report by Fred Girshick, Infineum USA, published in Proceedings of the 70th Annual
Meeting of the Locomotive Maintenance Officers Association (LMOA), Chicago, Illinois – September 21-24, 2008
19 Options for Improving the Energy Efficiency of Intermodal Freight Trains, Paper No.1916 by Y.C. Lai and C.P.L. Barkan, University of Illinois Urbana-
Champaign, published in the Journal of the Transportation Research Board – 2005
20 Wi-Tronix WiPUs to be Installed on CN Distributed Braking Cars, Press Release, Wi-Tronics LLC, Bolingbrook, Illinois – October 18, 2008
29 LEM 2008