FRA issues bulletin on train-control software malfunction

The Federal Railroad Administration (FRA) this week released a safety bulletin about a software defect found in the interoperable electronic train management system’s (I-ETMS) onboard software.

The purpose of the bulletin is to ensure rail industry constituents — including railroad employees and contractors — are aware of the software defect and to underscore the specific short-term mitigations recommended by the applicable I-ETMS supplier. The defect might cause a speed restriction within a zone not to be enforced by a positive train-control (PTC) system, the FRA bulletin states.

The software defect was found during lab testing and has not yet occurred in a railroad operating environment. Given the unique series of circumstances that must occur for the defect to materialize, the risk associated with it is considered low at this point, FRA officials said. A fix for the defect is being developed.

Until the fix is available, the FRA is reminding railroads that the supplier of the onboard I-ETMS software recommends they immediately implement the following short-term mitigations to ensure safe PTC operations:
• Instruct crews to avoid manually changing a train’s direction through the “select direction” soft key when over, or immediately adjacent to, a switch; and
• If it's necessary to change a train’s direction through the select direction soft key, cut out the PTC system and re-initialize it with the correct timetable direction to allow the onboard system to re-acquire the status of the switch under the train and remove the exclusion zone.