Reducing Fuel Consumption

Reducing Fuel Consumption and Carbon Emissions

The previous page offered a generalised summary of modifications that can be expected to result in boosting of locomotive performance.  This page focusses on the associated benefits of reduced fuel consumption and consequent reductions in carbon emissions.

Any modification that improves a locomotive’s performance (in terms of power output), is likely to reduce its specific fuel consumption (i.e. its fuel consumption per unit of work output).  And any reduction in fuel consumption will result in a reduction in carbon emissions.

Reducing fuel consumption and carbon emissions can be approached in two ways:

  1. Improve combustion to increase the energy transferred from the fuel to the generation of steam;
  2. Reduce Specific Steam Consumption, thereby reducing the consumption of steam and the fuel that is required to generate it.

Dealing with each in turn:

Improving Combustion: In the case of coal burning locomotives, combustion may be improved and fuel carry-over reduced by either:

  • Fitting the firebox with a combustion chamber to increase its volume and thus increase the residence time of the fuel/air mixture in the firebox; or
  • Converting the firebox to a Gas Producer Combustion System (GPCS).  This reduces the volume (and hence velocity) of “primary” air passing through the firebed and thereby reduce its ability to lift unburne fuel particles off the surface (and thence through the tubes and out of the chimney).  Instead an increased volume of “secondary” air is passed over the top of the firebed to burn off combustible gases generated in (and released from) the firebed.

In the case of oil burning locomotives, provided the firebox is large enough to allow complete combustion, and provided the fuel burner is well designed and operating efficienty, there should be no measurable fuel carry-over.

Specific steam consumption can be reduced through any or all of the following:

Any of the above measures will result in a reduction of fuel and water consumption for any given duty.