CSX Expands Automatic Engine Stop-Start Upgrades

CSX has implemented technology upgrades across its locomotive fleet to reduce fuel use, emissions and operating expenses. Central to the initiative is the enhancement of its Automatic Engine Stop-Start (AESS) system, which reduces unnecessary locomotive idling while maintaining operational readiness.

Automatic Engine Stop-Start System
The AESS platform automatically shuts down locomotive engines during periods of inactivity and restarts them when required for operations. Freight locomotives can consume significant fuel while idling, particularly during yard operations or dwell time between assignments. By automating engine shutdown and restart sequences, AESS minimizes avoidable fuel burn and associated emissions.

The system monitors operating conditions to ensure that shutdown occurs without compromising safety or performance, enabling immediate restart when the locomotive is needed.

AESS Assist and Battery Support
In 2024, the CSX Mechanical team introduced AESS Assist, an upgrade designed to improve shutdown performance and enhance restart reliability. The system provides additional battery support during engine cranking, reducing strain on onboard electrical systems.

Improved battery management is expected to extend battery service life over time, lowering maintenance frequency and replacement costs. Enhanced cranking support also supports consistent restart performance, which is critical for maintaining operational schedules.

Software Enhancements in Collaboration with Wabtec
Working with Wabtec, CSX implemented software upgrades to the AESS platform. The updated control logic extends the allowable engine shutdown duration without requiring idling to maintain system readiness.

By increasing the maximum shutdown window, locomotives can remain off for longer periods when inactive, further reducing fuel consumption and emissions. Software optimization complements hardware improvements to maximize overall efficiency gains.

Role in Fleet Efficiency Strategy
Automatic Engine Stop-Start technology forms part of CSX’s broader strategy to optimize locomotive performance and lower operational costs. Reducing idling directly decreases diesel consumption and associated greenhouse gas emissions across the rail network.

Through hardware enhancements, battery support improvements and updated control software, CSX continues to refine its fleet management approach to improve fuel efficiency while maintaining reliability in freight operations.