StacksVerified U.S. regulatory reference

49 CFR §236.309

Verified against eCFR.gov as of June 20, 2026View official text on eCFR.gov ↗
  1. (a)A loss of shunt of 5 seconds or less shall not permit an established route to be changed at an automatic interlocking.
  2. (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.