{"data":{"id":"us/49-cfr-236.729","jurisdiction":"us","citation":"49 CFR 236.729","heading":"Cock, double heading.","body":"A manually operated valve by means of which the control of brake operation is transferred to the leading locomotive.","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 G—Definitions"],"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":"8c3a243c509b73fd2c950b4487f3523f9513269b512dddc87785fc8cb2e99450","source_id":"us-cfr","stale":true,"prev":"us/49-cfr-236.728","next":"us/49-cfr-236.730"},"notice":"GroundRules: Original legal text. Not legal advice."}