49 C.F.R. § 236.309 Loss of shunt protection; where required.
Title 49 - Transportation
(a) A loss of shunt of 5 seconds or less shall not permit an established route to be changed at an automatic interlocking. (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. [49 FR 3385, Jan. 26, 1984]
Title 49: 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
Standards
§ 236.309 Loss of shunt protection; where required.
