Temporal Assessment of the Embodied Greenhouse Gas Emissions of a Toronto Streetcar Line
Abstract
Introduction
Research Context
510 Spadina Streetcar
Stage | Dates | Construction activities |
---|---|---|
Stage 1 (City of Toronto Archives 1986) | 1987–1990 (Howell 1990; Smith 1987) | • 2.2 km of at-grade ROW |
• 0.12 km long portal | ||
• Underground platforms | ||
Stage 2 (City of Toronto Archives 1990) | 1992–1997 (James 1992; Leckie 1997) | • Track-work and curbs along 2.4-km section of Spadina Ave. |
• Entrance portal and platform at Spadina subway station | ||
• Platforms along a 3.3-km section | ||
Stage 1M (Waterfront Toronto and City of Toronto 2009) | 2012–2014 (Waterfront Toronto and City of Toronto 2009) | • 1.3-km section of track was demolished and reconstructed |
Stage 2M (City News Toronto 2014; Toronto Transit Commission 2012, 2013, 2015b) | 2012–2015 (City News Toronto 2014; Toronto Transit Commission 2012, 2013, 2015b) | • Each of the four major unions (special tracks) along the route were rebuilt. |
• One union was reconstructed each summer. |
Data Sources
Methods
Emissions from Construction Materials
Estimating Material Consumption in At-Grade Structures
Feature | Stage 1 (City of Toronto Archives 1986) | Stage 2 (City of Toronto 2001) | Stage 1M, 2M (City of Toronto 2014a) |
---|---|---|---|
Track type | Embedded | Embedded | Embedded |
Track gauge (mm) | 1,495 | 1,495 | 1,495 |
Rail section used | 100 lb A.R.A-A | 100 lb A.R.A-A (assumed same rail section used for Stage 2 constructions as stage 1 because no additional information was available) | 115 lb A.R.E.A (City of Toronto 2008) |
Foundation | Tangent track: 75-mm thick layer of HI-60 Styrofoam placed on top of subgrade; Special track: 600-mm thick layer of crushed limestone placed on top of subgrade | Compacted gravel foundation used in all track sections | Compacted gravel foundation used in all track sections |
Track slab depth (mm) | 610 | 625 | 680 |
Width of track-work (mm) | 6,720 | 5,735 | 5,735 |
Tie specifications | Tracks mounted to foundation slab via direct-fixation system; no ties were used | Creosote impregnated hardwood ties used (cross section: ) spaced 610 mm apart (Project Manager for the City of Toronto, personal communication, 2017) | Steel I-beam ties— (City of Toronto 2014b) |
Note: If no source is listed for a given piece of information, assume that the default source for the construction stage in question was used, as listed in the heading.
Stage | Standard curved track-section | Special track-sections (located in intersections only) |
---|---|---|
Stage 1 | NP4aM girder railway is used only on one side of the tracks | NP4aM girder railway is used on both sides of the track. Creosote hardwood ties included at a spacing of 610 mm (same as Stage 2 constructions) |
Stage 2 | NP4aM girder railway is used only on one side of the tracks. Tie spacing unchanged compared with straight track-sections (original spacing is 610 mm, less than what is specified in the 2008 drawing; however, because generally curved sections require more support, the original spacing of 610 mm is preserved) | NP4aM girder railway is used on both sides of the track. Tie spacing unchanged compared with straight track-sections (original spacing is 610 mm, less than what is specified in the 2008 drawing; however, because generally curved sections require more support, the original spacing of 610 mm is preserved) |
Stages 1M and 2M | NP4aM girder railway is used on only one side of the tracks. Tie spacing 914 mm | NP4aM girder railway is used on both sides of the track. Tie spacing 1,524 mm |
Source: Data from City of Toronto (2008).
Feature | Narrow platform (City of Toronto Archives 1986) | Wide platform (City of Toronto Archives 1990) | Wide, ramped platform (City of Toronto Archives 1990) | New wide platform (Waterfront Toronto and City of Toronto 2009) |
---|---|---|---|---|
Stage | 1 | 2 | 2 | 1M |
Number of platforms constructed | 8 | 16 | 8 | 6 |
Width (mm) | 1,500 | 2,500 | 2,500 | 2,400 |
Length (mm) | 30,000 | 30,000 | 30,000 (plus a 12,000-mm long access ramp) | 30,000 |
Depth of concrete slab (mm) | 830 | 830 (assumed to be the same as narrow platforms) | 830 (average height of the ramp is 750 mm) | 830 (assumed to be the same as narrow platforms) |
Foundation specifications | 75-mm thick HI-60 styrofoam foundation above the subgrade | 150-mm thick gravel foundation (City of Toronto 2001) | 150-mm thick gravel foundation (City of Toronto 2001) | 150-mm thick gravel foundation (assumed to be the same as wide platforms) |
Key platform finishings | Two steel splashboards 915-mm tall and 1,200-mm long | Three steel bus shelters 2,100-mm tall and 3,720-mm wide | Three steel bus shelters 2,100-mm tall and 3,720-mm wide | Three plastic bus shelters 2,200-mm tall and 4,500-mm wide |
Steel railing running the length of the platform | Steel railing running the length of the platform | Steel railing running the length of the platform |
Note: If no source is listed for a given piece of information, assume that the default source, as listed in the heading, was used. Information on platform finishings was determined during two site visits to different platforms along the line (site visit, 2017-06-15, 2017-06-20).
Stage | Platform | Key platform finishings |
---|---|---|
Stage 1 | Narrow platform (City of Toronto Archives 1986) | Two steel splashboards 915-mm tall and 1,200-mm long |
Stage 2 | Wide platform (site visit, 2017-06-15) | Three steel bus shelters 2,100-mm tall and 3,720-mm wide |
Steel railing running the length of the platform | ||
Stage 2 | Wide, ramped platform (site visit, 2017-06-15) | Three steel bus shelters 2,100-mm tall and 3,720-mm wide |
Steel railing running the length of the platform | ||
Stage 1M | New wide platform (site visit, 2017-06-20) | Three plastic bus shelters 2,200-mm tall and 4,500-mm wide |
Steel railing running the length of the platform |
Estimating Material Consumption in Underground Structures
Estimating Waste Generation
Emission Factors for Material Emissions
Material | Material emission factors, () | ||
---|---|---|---|
Stage 1 | Stage 2 | Stages 1M and 2M | |
Concretea | 284.5 | 280.7 | 282.9 |
Steel—track and tiesb | 9,753.8 | 9,753.8 | 9,753.8 |
Steel—rebarb | 4,330.6 | 4,330.6 | 4,330.6 |
Steel—platform finishingsb | 13,459.1 | 13,459.1 | 13,459.1 |
Woodc | 609.0 | 609.0 | 609.0 |
Granular A, track infill and crushed limestonec | 11.6 | 11.6 | 11.6 |
Loose fill—soilc | 35.0 | 35.0 | 35.0 |
HDPEc | 2,419.2 | 2,419.2 | 2,419.2 |
Polystyrenec | 113.4 | 113.4 | 113.4 |
Unshrinkable fillc | 125.1 | 125.1 | 125.1 |
General plasticc | 3,177.0 | 3,177.0 | 3,177.0 |
Emissions from Construction Machinery and Transportation
Estimating Operating Times for Construction Machinery
Estimating Distance Traveled and Idling Times for Transportation Machinery
Emission Factors for Machinery Emissions
Machine | Activity | Source | Emission factor () |
---|---|---|---|
Excavators | Normal operation | Excavators (Frey et al. 2010) | 24,327 |
Wheel loaders | Normal operation | Wheel loaders (Frey et al. 2010) | 10,008 |
Skid steer loader | Normal operation | Skid steer loaders (Frey et al. 2010) | 8,721 |
Heavy-duty truck, dump truck, refueling trucks, concrete mixers | Driving | Graham et al. (2008) | |
Idling | Off-road truck (Lewis et al. 2012) | 11,000 | |
Paving machine | Normal operation | Excavators (Frey et al. 2010) | 24,327 |
Cold planers | Normal operation | Off-road truck (Frey et al. 2010) | 19,842 |
Mini-excavators | Normal operation | Skid-steer loader (Frey et al. 2010) | 8,721 |
Compactors | Normal operation | Backhoes (Frey et al. 2010) | 10,008 |
Portable crane; road sweeper; vans with boom lift | Normal operation | Off-road trucks (Frey et al. 2010) | 19,842 |
Rail threader | Normal operation | Skid-steer loader (Frey et al. 2010) | 8,721 |
Note: Emission factors for machines listed in bold were not reported in the literature.
Key Exclusions
Results
Material Emissions
Construction Machinery and Transportation Emissions
Overall Emissions and Future Projections
Discussion
Conclusion
Notation
- CMT emissions generated during reconstruction of College and Spadina intersection;
- construction emissions generated during reconstruction of College and Spadina intersection;
- construction emissions generated by machine ;
- material emissions;
- material emissions for th stage of construction;
- material emissions produced by material during th stage of construction;
- material emissions generated in reconstruction of College and Spadina intersection;
- number of trips taken per day by machine ;
- distance traveled by transport machine per trip (round-trip);
- idling time for machine ;
- operating time for machine ;
- gross material consumption;
- material consumption for material during th stage of construction;
- proportion of total emissions generated by construction machinery or transportation;
- emission factor for transportation machinery;
- emission factor for transportation machine ;
- emission factor for materials;
- emission factor for material ;
- emission factor for construction machinery;
- idling emission factor for machine ;
- emission factor for machine ;
- transportation emissions;
- transportation emissions for machine generated when driving;
- transportation emissions for machine generated when idling; and
- transportation emissions generated during reconstruction of College and Spadina intersection.