Section 235.7 - Changes not requiring filing of application(a) It is not necessary to file an application for approval of the following discontinuances: (1) Removal of block signal system, interlocking, traffic control system, automatic train stop, train control, or cab signal system from track approved for abandonment by formal proceeding;(2) Removal of devices and associated signals used to provide protection against unusual contingencies such as landslide, burned bridge, high water, high and wide load, or tunnel protection when the unusual contingency no longer exists;(3) Removal of an interlocking where a drawbridge has been permanently closed by the formal approval of another government agency; or(4) Removal from service not to exceed 6 months of block signal system, interlocking, or traffic control system necessitated by catastrophic occurrence such as derailment, flood, fire, or hurricane; or(5) Removal of an intermittent automatic train stop system in conjunction with the implementation of a positive train control system approved by FRA under subpart I of part 236 of this chapter.(b) When the resultant arrangement will comply with part 236 of this title, it is not necessary to file for approval to decrease the limits of a system as follows: (1) Decrease of the limits of an interlocking when interlocked switches, derails, or movable-point frogs are not involved;(2) Removal of electric or mechanical lock, or signal used in lieu thereof, from hand-operated switch in automatic block signal or traffic control territory where train speed over the switch does not exceed 20 miles per hour; or(3) Removal of electric or mechanical lock, or signal used in lieu thereof, from hand-operated switch in automatic block signal or traffic control territory where trains are not permitted to clear the main track at such switch.(c) When the resultant arrangement will comply with part 236 of this title, it is not necessary to file an application for approval of the following modifications: (1) A modification that is required to comply with an order of the Federal Railroad Administration or any section of part 236 of this title;(2) The installation of an automatic block signal or a traffic control system to replace manual block or non-signaled territory;(3) The installation of a traffic control system to replace a roadway automatic block signal system (discontinuance of an automatic train stop, train control, or cab signal system is not permitted without FRA approval);(4) The installation of an automatic train stop, train control, or cab signal system in an existing automatic block or traffic control system;(5) The installation of a continuous inductive automatic train stop system to replace an existing intermittent inductive automatic train stop system;(6) The installation of a continuous inductive automatic train stop system to supplement an existing automatic cab signal system;(7) The installation of an automatic train control system to replace an existing automatic train stop system or to supplement an existing automatic cab signal system;(8) The installation of an interlocking to replace existing stop signs, gates, or pipe-connected derails protecting a railroad crossing at grade;(9) The installation of all relay type locking to replace existing mechanical or electromechanical locking of an interlocking;(10) The installation of an additional controlled point in existing traffic control system;(11) The installation of an interlocking in an existing block signal system;(12) The conversion of a hand-operated switch, a hand-operated switch locked either electrically or mechanically, or a spring switch to a power-operated switch;(13) The conversion of a spring switch to a hand-operated switch, or to a hand-operated switch locked either electrically or mechanically;(14) The removal or relocation of signals associated with a spring switch converted to hand operation;(15) The installation, relocation, or removal of signals to specifically provide adequate stopping distance;(16) The change of aspects;(17) The relocation of a signal to improve preview of signal aspect visibility;(18) To replace a signal with a signal of another type;(19) To change an approach signal to operative or inoperative signal, or remove an approach signal not required by § 236.310 of this title;(20) The change in location of a machine from which an interlocking or traffic control system is controlled;(21) The closing of a manual block station or the change in hours during which a manual block station is attended;(22) The change in hours during which a manual interlocking is attended provided the interlocking operates for all routes over which train movements are permitted;(23) The installation of devices used to provide protection against unusual contingencies such as landslide, burned bridges, high water, high and wide loads, or dragging equipment;(24) The installation, relocation, or removal of signals, interlocked switches, derails, movable-point frogs, or electric locks in an existing system directly associated with: (i) The installation of new track;(ii) The elimination of existing track other than a second main track;(iii) The extension or shortening of a passing siding;(iv) Elimination of second main track where signal system mn retained main track is arranged to provide both opposing and following protection for train movements provided second main track is physically removed; or(v) A line relocation; or(vi) The conversion of pole line circuits to electronic (coded) track circuits provided that the railroad gives notice and a profile plan of the change to the FRA regional office having jurisdiction over that territory at least 60 days in advance of the change. The railroad must also at the same time provide a copy of the notice and profile plan to representatives of employees responsible for maintenance, inspection and testing of the signal system under 49 CFR part 236 . The signal system modification will be deemed acceptable, unless within 60 days, the Regional Adminstrator stays action by written notice to the railroad and refers the issue to the Railroad Safety Board for decision.(25) The temporary or permanent arrangement of existing systems necessitated by highway-rail grade crossing separation construction. Temporary arrangements shall be removed within 6 months following completion of construction.49 FR 3380, Jan. 26, 1984, as amended at 61 FR 33873, July 1, 1996; 75 FR 2698 , Jan. 15, 2010