Ogab® Report – Impact of Reduced Fuel Consumption on Railways
Rail Transport Fuel Consumption
In UK during 2018-19 financial year, passenger rail services consumed 3,976 million kWh of electricity and 469 million litres of diesel. Of the total 15,847 km of route open for trains (31,091 km of tracks) 38% is electrified (ORR, 2019a). So Diesel Multiple Units (DMUs), trains powered with diesel, are used because part of the lines are not electrified.
The Class 220 Voyager is a diesel-electric multiple-unit manufactured by Bombardier Transportation that operates in Country Cross network. In fact, all Country Cross trains are powered with diesel and 34 trains of the total 92 train sets are Class 220 Voyager.
The key characteristics of this train related to fuel consumption are:
- 4 cars per trainset
- Each car is equipped with a Cummins QSK19 diesel engine of 750 hp (560 kW) at 1800rpm
- Each car is equipped with a fuel tank of 1,300 litres of diesel
- Maximum range of approximately 1,350 miles (2,170 km) between each refuelling
- Class 220 operates at a top speed of 125 mph (200 km/h)
- It contains 200 seats
In order to calculate fuel consumption of Class 220, we used the amount of fuel that a train carries in the 4 cars and the maximum distance between each refueling.
With this calculation, a Class 220 Voyager consumes on average 3.85 litres of diesel per mile.
It has to be considered that the consumption is directly dependent on the speed. In Figure 1, it is presented the linear relationship between speed and energy used by trains, so at more speed, more energy used. But also other factors will determine the fuel consumption: train weight, seat capacity, the number of stops during the route.
Figure 1 Relationship between energy usage and speed. Source: RSSB, 2007
In this section, we analyse the fuel consumption and its impact. The assumptions made, based on data from RSSB, are:
- A passenger train in UK runs 330 days a year
- A Class 220/2201/222 runs an average 640 miles per day and power car
- A Class 220/2201/222 runs each day 15.1 hours
In the next table, the assumed fuel consumption is presented.
Table 1 Fuel consumption per mile, 1 month, 1 year and 5 years.
|Diesel consumed per trainset (litres)|
The related environmental impacts of current average fuel consumption is presented below.
Table 2 Environmental impacts of fuel consumption (fuel production and combustion) per 1 mile, during 1 month, 1 year and 5 years.
|Environmental impact category||Units||One Class 220 Voyager trainset|
|1 mile||1 month||1 year||5 years|
|Climate change||kg CO2 eq||11.3||198,040||2,376,481||11,882,407|
|Stratospheric ozone depletion||Kg CFC11 eq||5.97E-06||0.11||1.26||6.31|
|Ionizing radiation||kBq Co-60 eq||0.077||1,364||16,368||81,840|
|Ozone formation, human health||kg NOx eq||0.18||3,239||38,864||194,319|
|Fine particulate matter formation||kg PM2.5 eq||0.024||416||4,996||24,982|
|Ozone formation, terrestrial ecosystems||kg NOx eq||0.19||3,276||39,316||196,579|
|Terrestrial acidification||kg SO2 eq||0.074||1,307||15,688||78,440|
|Freshwater eutrophication||kg P eq||4.28E-06||0.08||0.90||4.52|
|Terrestrial ecotoxicity||kg 1.4-DBC e||7.90||138,979||1,667,746||8,338,731|
|Freshwater ecotoxicity||kg 1.4-DBC e||3.14E-03||55||663||3,314|
|Marine ecotoxicity||kg 1.4-DBC e||8.06E-03||142||1,702||8,508|
|Human carcinogenic toxicity||kg 1.4-DBC e||1.20E-03||21||253||1,265|
|Human non-carcinogenic toxicity||kg 1.4-DBC e||0.17||2,929||35,146||175,732|
|Land use||m2a crop eq||2.21E-03||39||468||2,339|
|Mineral resources scarcity||kg Cu eq||4.31E-05||0.76||9.11||46|
|Fossil resource scarcity||kg oil eq||3.5||60,868||730,418||3,652,089|
|Cumulative energy demand||MJ||153||2,691,906||32,302,868||161,514,339|
According to UK Department for Transport, the carbon dioxide emissions per type of routes in UK are:
- Intercity: 14.48 kg CO2eq/mile
- LSE (London and South East): 10.62 kg CO2eq/mile
- Regional: 8.05 kg CO2eq/mile
So, a Class 220 Voyager has a consumption inside the average for trains.
Aerodynamic drag reduction benefits
Of all energy consumed by diesel DEMU, 68% is used by the engine to operate the train, 5% to provide auxiliary services to the train, such as ventilation and control, lightning and climatization, but 27% is lost, as it is shown in Figure 2, which means that strategies avoiding energy losses can result in a significant reduction on fuel consumption.
Figure 2 Energy usage on diesel Intercity DEMU (e.g. Class 221 Super-Voyager (200 km/h)) for the GB rail network. Source: RSSB, 2007
The inclusion of Ogab®’s Advanced TRS® system on the Class 220 Voyager proves to be very effective in reducing the drag coefficient, 22.34%. This means it is possible to create a reduction of 11.17% in fuel consumption.
In this section, the environmental benefits of a 11.17% fuel reduction is analysed.
Considering that a Class 220 Voyager consumes 3.85 litres of diesel per mile, the potential savings are:
- 0.43 litres of diesel saved per mile per train
- 7,572 litres of diesel saved per month per train
- 90,869 litres of diesel saved per year per train
- 454,346 litres of diesel saved in a 5 years period per train
This potential fuel consumption reduction can be translated into significant emissions savings. In the following table, the potential environmental benefits are presented:
Environmental impacts saved due to 11.17% fuel reduction in one Class 220 Voyager train.
1 mile 1 Month 1 Year 5 Years
Climate Change (kg Co2 eq) 1.26 22,121 265,453 1,327,265
For further information on the full impacts of fuel consumption view our comprehensive report by clicking below.
Department for Transport (2007) Delivering a Sustainable Railway. Available at: https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/243207/7176.pdf
Givoni, M., Brand, C., Watkiss, P., 2009. Are Railways ‘Climate Friendly’?, Built Environment, 35 (1), 70-86(17). Available at: https://ora.ox.ac.uk/objects/uuid:cd7d3eb7-e57c-427d-9ec6-70da72389cce/download_file?safe_filename=Are%2Brailways%2Bclimate%2Bfriendly%2B-%2BGivoni%2BBrand%2BWatkiss%2B-%2Baccepted%2Bmanuscript.pdf&file_format=application%2Fpdf&type_of_work=Journal+article
ORR (2019a) 2018-19 Annual Statistical Release – Rail Infrastructure and Assets. Office of Rail and Road. Available at: https://dataportal.orr.gov.uk/media/1532/rail-infrastructure-assets-2018-19.pdf
ORR (2019b) 2018-19 Annual Statistical Release – Rail Emissions. Office of Rail and Road. Available at: https://dataportal.orr.gov.uk/media/1550/rail-emissions-2018-19.pdf
RSSB (2007) T618 – Improving the efficiency of traction energy use. Rail Safety and Standards Board
Spielmann, M., Bauer, C., Dones, R., Tuchschmid, M. (2007) Transport Services. Ecoinvent report No. 14. Swiss Center for Life Cycle Inventories, Dübendorf, 2007
Annex. Impact categories description
|Environmental impact category||Unit||Description|
|Climate change||kg CO2 eq||An increased atmospheric concentration of greenhouse gases will increase the radiative forcing capacity leading to an increase in the global mean temperature (°C). Increased temperature ultimately results in damage to human health and ecosystems.|
|Stratospheric ozone depletion||Kg CFC11 eq||Emissions of Ozone Depleting Substances ultimately lead to damage to human health because of the resultant increase in UVB radiation. Chemicals that deplete ozone are relatively persistent and have chlorine or bromine groups in their molecules that interact with ozone (mainly) in the stratosphere. This increased radiation negatively affects human health, thus increasing the incidence of skin cancer and cataracts.|
|Ionizing radiation||kBq Co-60 eq||Anthropogenic emissions of radionuclides are generated in the nuclear fuel cycle (mining, processing and waste disposal), as well as during other human activities, such as the burning of coal and the extraction of phosphate rock. Exposure to the ionizing radiation caused by these radionuclides can lead to damaged DNA molecules and thus affect human health.|
|Ozone formation, human health||kg NOx eq||Ozone is not directly emitted into the atmosphere, but it is formed as a result of photochemical reactions of NOx and Non Methane Volatile Organic Compounds (NMVOCs). This formation process is more intense in summer. Ozone is a health hazard to humans because it can inflame airways and damage lungs.|
|Fine particulate matter formation||kg PM2.5 eq||Air pollution that causes primary and secondary aerosols in the atmosphere can have a substantial negative impact on human health, affecting the upper part of the airways and lungs when inhaled.|
|Ozone formation, terrestrial ecosystems||kg NOx eq||Ozone is not directly emitted into the atmosphere, but it is formed as a result of photochemical reactions of NOx and Non Methane Volatile Organic Compounds (NMVOCs). Ozone can have a negative impact on vegetation, including a reduction of growth and seed production, an acceleration of leaf senescence and a reduced ability to withstand stressors.|
|Terrestrial acidification||kg SO2 eq||Atmospheric deposition of inorganic substances, such as sulphates, nitrates and phosphates, cause a change in acidity in the soil. This change in acidity can affect the plant species living in the soil, causing them to disappear|
|Freshwater eutrophication||kg P eq||Freshwater eutrophication occurs due to the discharge of nutrients into soil or into freshwater bodies and the subsequent rise in nutrient levels, i.e. phosphorus and nitrogen. Environmental impacts related to freshwater eutrophication are numerous. They follow a sequence of ecological impacts offset by increasing nutrient emissions into fresh water, thereby increasing nutrient uptake by autotrophic organisms such as cyanobacteria and algae, and heterotrophic species such as fish and invertebrates. This ultimately leads to relative loss of species.|
|Terrestrial ecotoxicity||kg 1.4-DBC e||Human toxicity and ecotoxicity accounts for the environmental persistence (fate), accumulation in the human food chain (exposure), and toxicity (effect) of a chemical. This can result in affected species and disease incidences, leading finally to damage to ecosystems and human health.|
|Freshwater ecotoxicity||kg 1.4-DBC e|
|Marine ecotoxicity||kg 1.4-DBC e|
|Human carcinogenic toxicity||kg 1.4-DBC e|
|Human non-carcinogenic toxicity||kg 1.4-DBC e|
|Land use||m2a crop eq||Land use includes the direct, local impact of land use on terrestrial species via change of land cover and the actual use of the new land. Change of land cover directly affects the original habitat and the original species composition accordingly.|
|Mineral resources scarcity||kg Cu eq||Assessment of consumption of natural resources (distinguished in two indicators depending on whether the resources are energy or non-energy) including a weighting of these resources according to their scarcity and the speed of their exploitation. The more the resource is considered as scarce and exploited, the more the value of the indicator increases and the more the product contributes to the depletion of resources.|
|Fossil resource scarcity||kg oil eq|
|Water consumption||m3||Water consumption is the use of water in such a way that the water is evaporated, incorporated into products, transferred to other watersheds or disposed into the sea. Water that has been consumed is thus not available anymore in the watershed of origin for humans nor for ecosystems|
|Cumulative energy demand||MJ||The Cumulative Energy Demand represents the direct and indirect energy use throughout the life cycle, including the energy consumed during the extraction, manufacturing and disposal of the raw and auxiliary materials.|