EMPTY FREIGHT CAR DISTRIBUTION STUDY
As freight cars represent a very large investment for the railways, their efficient utilization is of prime importance for the profitability of operations. The dynamic behavior of empty car systems, as determined by the structure, the information flows and the procedures used, dictate for a large part the adequacy of such a system. Improper or untimely responses to changing conditions may amplify demand fluctuations, causing car shortages to be followed by acute congestion. In order to study the dynamic characteristics of empty freight car allocation systems, Industrial Dynamics simulations are performed on models of centralized and decentralized structures, and under various external conditions. It is found that the structure of the system itself is of secondary importance, but that such factors as the average lengths of the delays in the system, and the proper consideration of in-transit inventories have a large influence on the stability of a system. In the context of improving short-term car allocation between autonomous car service centers, an allocation package is developed, which uses the Ford-Fulkerson "Out-of-Kilter" algorithm as its basis. Such a program finds the optimal allocation of cars between service centers, given that forecasts of shortages or surplus of cars for each service center for the coming five days are available. An application of this technique is presented, using the Western half of the Canadian Pacific mainline network as a basis.
- This study was funded by the Transportation Development Agency of Canada.
Queens UniversityKingston, Ontario Canada K7L 3N6
- Ouimet, G P
- Fullerton, H V
- Publication Date: 0
- TRT Terms: Car distribution (Railroads); Car shortages (Railroads); Car utilization (Railroads)
- Old TRIS Terms: Car shortage
- Subject Areas: Freight Transportation; Railroads;
- Accession Number: 00054706
- Record Type: Publication
- Source Agency: Canadian Roads and Transportation Association
- Files: TRIS
- Created Date: Jul 15 1974 12:00AM