49 CFR §236.739
Verified against eCFR.gov as of June 20, 2026View official text on eCFR.gov ↗
A manually operated electric switch or pneumatic valve by means of which, on a locomotive equipped with an automatic train stop or train control device, an automatic brake application can be forestalled, or by means of which, on a locomotive equipped with an automatic cab signal device, the sounding of the cab indicator can be silenced.