A carbon footprint analysis of railway sleepers in the United Kingdom
A carbon footprint analysis of railway sleepers in the United Kingdom
This paper provides an assessment of the lifecycle Greenhouse Gas (GHG) emissions associated with the four most common sleeper (railroad tie or cross-tie in North America) types present in the UK rail network. It estimates the embodied material, process and transport emissions linked with the lifecycle activities of construction, relay/renewal and end-of-life of these variants at low and high traffic tonnage. The analysis suggests that at low traffic loads, the softwood sleepers perform the best over the whole simulated-period. At high traffic loads, the concrete sleepers outperform all other variants in terms of lifecycle CO2e emissions, followed by hardwood, softwood and steel. Regardless of the scenario examined, the steel sleepers perform the worst due to the carbon intensive nature of their manufacturing process. This performance gap is amplified at high traffic loads, as their service life is excessively compromised. The analysis reveals that the end-of-life pathway of timber is a critical determinant of its footprint. Results suggest that the impact of disposing of these sleepers results in their footprint being magnified. Nevertheless, if a minimum of 50% follows the combustion pathway with subsequent heat recuperation, then a GHG reduction potential of between 11% and 18% of their footprint is feasible. From a whole-lifecycle cost lens, for higher tonnage routes, the choice of concrete sleepers results in considerable financial savings. If the infrastructure manager was to install sleepers with stiff under sleeper pads (USPs), it may achieve additional economic and GHG savings, with potential for increasing the latter using recycled carbon-neutral USPs.
Carbon footprint, Greenhouse gas emissions, Life cycle assessment, Life cycle costing, Rail track, Railway sleepers
Rempelos, Georgios
c58f755e-d094-489b-9716-0a8fb061ce8a
Preston, Jonathan
ef81c42e-c896-4768-92d1-052662037f0b
Blainey, Simon
ee6198e5-1f89-4f9b-be8e-52cc10e8b3bb
April 2020
Rempelos, Georgios
c58f755e-d094-489b-9716-0a8fb061ce8a
Preston, Jonathan
ef81c42e-c896-4768-92d1-052662037f0b
Blainey, Simon
ee6198e5-1f89-4f9b-be8e-52cc10e8b3bb
Rempelos, Georgios, Preston, Jonathan and Blainey, Simon
(2020)
A carbon footprint analysis of railway sleepers in the United Kingdom.
Transportation Research Part D: Transport and Environment, 81, [102285].
(doi:10.1016/j.trd.2020.102285).
Abstract
This paper provides an assessment of the lifecycle Greenhouse Gas (GHG) emissions associated with the four most common sleeper (railroad tie or cross-tie in North America) types present in the UK rail network. It estimates the embodied material, process and transport emissions linked with the lifecycle activities of construction, relay/renewal and end-of-life of these variants at low and high traffic tonnage. The analysis suggests that at low traffic loads, the softwood sleepers perform the best over the whole simulated-period. At high traffic loads, the concrete sleepers outperform all other variants in terms of lifecycle CO2e emissions, followed by hardwood, softwood and steel. Regardless of the scenario examined, the steel sleepers perform the worst due to the carbon intensive nature of their manufacturing process. This performance gap is amplified at high traffic loads, as their service life is excessively compromised. The analysis reveals that the end-of-life pathway of timber is a critical determinant of its footprint. Results suggest that the impact of disposing of these sleepers results in their footprint being magnified. Nevertheless, if a minimum of 50% follows the combustion pathway with subsequent heat recuperation, then a GHG reduction potential of between 11% and 18% of their footprint is feasible. From a whole-lifecycle cost lens, for higher tonnage routes, the choice of concrete sleepers results in considerable financial savings. If the infrastructure manager was to install sleepers with stiff under sleeper pads (USPs), it may achieve additional economic and GHG savings, with potential for increasing the latter using recycled carbon-neutral USPs.
Text
Manuscript_.v.final_GR_JMP_SB.v.4.1.1
- Accepted Manuscript
More information
Accepted/In Press date: 19 February 2020
e-pub ahead of print date: 28 February 2020
Published date: April 2020
Additional Information:
Funding Information:
This work was supported by the EPSRC-funded Track to the Future (EP/M025276/1) project. The authors would like to express their gratitude to Lucie Anderton and Lauren Brown from Rail Safety and Standards Board for kindly granting us access to the RSSB’s Rail Carbon Tool. The authors would also like to thank Network Rail and in particular Julian Williams for his support in providing data to carry out this research.
Publisher Copyright:
© 2020 Elsevier Ltd
Keywords:
Carbon footprint, Greenhouse gas emissions, Life cycle assessment, Life cycle costing, Rail track, Railway sleepers
Identifiers
Local EPrints ID: 438150
URI: http://eprints.soton.ac.uk/id/eprint/438150
ISSN: 1361-9209
PURE UUID: ec0f0668-4094-4e59-9a1a-92a6c2681b75
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Date deposited: 03 Mar 2020 17:41
Last modified: 17 Mar 2024 05:21
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Author:
Georgios Rempelos
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