{"data":{"id":"us/49-cfr-236.309","jurisdiction":"us","citation":"49 CFR 236.309","heading":"Loss of shunt protection; where required.","body":"(a) A loss of shunt of 5 seconds or less shall not permit an established route to be changed at an automatic interlocking.\n(b) A loss of shunt of 5 seconds or less shall not permit the release of the route locking circuit of each power-operated switch hereafter installed.","path":["Title 49—Transportation","Subtitle B—Other Regulations Relating to Transportation","CHAPTER II—FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION","PART 236—RULES, STANDARDS, AND INSTRUCTIONS GOVERNING THE INSTALLATION, INSPECTION, MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES","Subpart C—Interlocking"],"source_url":"https://www.ecfr.gov/api/versioner/v1/full/2026-08-25/title-49.xml","current_through":"2026-08-25","vintage":"","retrieved_at":"2026-08-27T02:26:34Z","sha256":"f932016f7eb2073c05e838abe026a56d2c8b3dab05c22b422fe57a4a20a1fafc","source_id":"us-cfr","stale":true,"prev":"us/49-cfr-236.308","next":"us/49-cfr-236.310"},"notice":"GroundRules: Original legal text. Not legal advice."}