WASHINGTON — The Federal Railroad Administration has issued a safety advisory after identifying a design issue with positive train control that makes it possible for a crew member to circumvent PTC enforcement.
The advisory, published earlier this month in the Federal Register, says the interface design issue allows crews to manually operate the cut-out value prior to the PTC system activating the brakes, which disables the PTC system and keeps it from operating the brakes to avoid a collision, over-speed derailment, movement in a work zone, or movement through a switch left in the wrong position.
The advisory recommends that railroads remind crew members that circumventing PTC is subject to civil penalty or operating disqualification, and that railroads assess the extent to which systems are subject to this circumvention and correct the issue.
According to the advisory, the ability to circumvent the system in this manner exists only in the design of the interface for some locomotives and cab cars, with the FRA believing the systems of most concern involve older locomotives with mechanical brakes, as opposed to newer units with electronic braking. The advisory cites three instances of such overriding of the system during testing in May and July of this year.