Inertial Tractive Effort as an Explanatory Variable in the Analysis of Locomotive Fuel Savings

Details

• Creators:
  Oldknow, Kevin ; Cotter, John ; Eadie, Don ; Elvidge, David ; Kennedy, Wayne ; Nedunoori, Srini ; Peters, John ; Replogle, Justin ; Ronasi, Hamed ; Stevens, Rob ; Weitzel, Loerella
• Corporate Creators:
  LB Foster Rail Technologies ; Union Pacific Railroad ; First Analytics
• Subject/TRT Terms:
  Alternate Fuels Costs Fuels Locomotives Railroad Transportation Rolling Stock
• Resource Type:
  Research Paper
• Right Statement:
  Public Domain
• Geographical Coverage:
  United States
• Corporate Publisher:
  International Heavy Haul Association
• Abstract:
  The purpose of the work presented has been the development of an explanatory variable that characterizes train handling effects, allowing for the identification of changes in locomotive fuel consumption over a given territory (for example in response to Top of Rail Friction Modifier (TORFM) application) with improved confidence. To generate the explanatory variable, the concept of Inertial Tractive Effort (ITE) was developed. Given the total instantaneous tractive effort (TE) dispatched by a locomotive consist to overcome all sources of resistance, ITE is an estimate of the portion spent overcoming inertial resistance to generate acceleration. Integrating ITE over time yields cumulative ITE (cITE), which is in essence an estimate of total energy spent on acceleration versus a train travelling at constant speed over the same territory. Analysis of data collected in revenue service on several Union Pacific coal routes has shown that cITE acts as an explanatory variable, effectively mitigating variability in the data and allowing for an improved confidence when analyzing the impacts of other variables such as TORFM application. With the incorporation of cITE as an explanatory variable in a multi-variable regression of locomotive fuel data collected over five months of revenue service operation on Union Pacific, the statistical power of the underlying model was improved to yield a P-value of 0.028 versus 0.202 otherwise (the corresponding fuel savings associated with TORFM application were estimated at 6.4%). The approach represents a novel and useful mechanism to handle fuel data variability, with the potential to underpin a broad range of analyses.
• Content Notes:
  Please cite: Oldknow, K., et al. Inertial Tractive Effort as an Explanatory Variable in the Analysis of Locomotive Fuel Savings. 2015.
• Format:
  PDF
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha-512:56000f18960445d654064d834c5bd9352a4a85196da946f378b8ffd096c611fff952a2de05d0c63bf047ee4311f3ca68773fd032a69fec6f88f29814119f3771
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/88128/dot_88128_DS1.pdf
• File Type:
  [PDF - 2.02 MB ]