The Implications of Heavy Axle Load Operations for Track Maintenance on Short Lines

Abstract

North American freight railways have increased axle loads on high volume commodities such as grain, coal, and ore because of the significant savings in overall operating costs that result from heavier cars and corresponding higher axle loads. The resulting savings are in spite of increased maintenance of way and structures costs that result form the operation of the heavier cars and higher axle loads. Testing and subsequent experience has shown that well maintained main line track with heavy rail, sound ties, and good ballast sections can support these higher axle loads, though with an increase in the “annual” maintenance costs due to greater track component damage and shortened component lives. However, short lines often operate track with light rail sections and marginal tie and ballast condition. The effect of these increased axle loads are not as well defined for this type of track and railway operation. Yet many short lines are facing the requirement to accept these heavier cars from their main line connecting partners. The implications of this to the short line operators can be potentially very significant. This paper presents the results of two specific studies performed on two different short line (regional) railroads on the effect of heavy axle load cars on present and future maintenance of way costs. This includes the potential need to upgrade track components such as rail, as well as the anticipated increase in maintenance costs in all of the key track maintenance areas to include rail, ties, and ballast (surfacing). One of the two study railroads already permits HAL 286,000 lb. cars on one line, and is looking to permit these HAL cars on several other lines that it operates. The second short line does not currently allow HAL equipment. In both cases, this paper examines the start up, short term and long term implications of operating 286,000 lb. cars on these two short line railroads.