An extensive study was made over a seven day period to determine if it would be feasible, from an air pollution viewpoint, to operate diesel locomotive powered trains through the St. Clair Tunnel. The trials in the tunnel were conducted using 175 C class GR-17 road switchers of General Motors Manufacture. In these engines the air blower, providing air for combustion, is driven directly off the drive shaft and therefore air intake is proportional to engine speed. The shape, dimensions, and absence of forced ventilation in the tunnel suggested the possibility of variations in exhaust gas concentrations at different points along the length of the tunnel. In addition, trains enter the tunnel on a down grade under their own momentum with engines idling and coast to about midpoint. To contend with this situation, it was necessary to collect air samples representing not only average conditions, but also fluctuating, peak, and residual conditions. Test methods are described. Concentrations of carbon monoxide found in the tunnel were well blow the maximum allowable concentration of 100 ppm for an 8 hour exposure period, but post-exposure figures indicated a slight trend toward higher carboxyhemoglobin saturation percentages in approximately half of the subjects. Concentrations of aldehydes were generally below the maximum allowable concentration of 5.0 ppm. Although average values for all samples taken for nitrogen dioxide were well below the maximum allowable concentration of 5 ppm, total oxides of nitrogen showed concentrations considerably in excess of 25 ppm. This is discussed. Smoke and particulate matter occurred in relatively high concentrations and resulted in the subsequent decision to install forced ventilation in the tunnel. Measured air flow displacement by the trains is also discussed.

  • Corporate Authors:

    Canadian Society for Chemical Engineers

    151 Slater Street
    Ottawa 4, ONo,   Canada 
  • Authors:
    • Rennie, R P
  • Publication Date: 1960-8

Media Info

Subject/Index Terms

Filing Info

  • Accession Number: 00041775
  • Record Type: Publication
  • Source Agency: Air Pollution Technical Information Center
  • Files: TRIS
  • Created Date: May 4 1973 12:00AM