In this chapter, the following terms have the meanings indicated. Terms Defined. “Height of a freight car” means the distance between the top of the rail and the top of the running board. “Main track” means track on which the authorized speed of freight trains is in excess of 30 miles per hour. “Overhead clearance” means the vertical distance from the level of the top of the highest rail to a structure or obstruction above. “Side of a freight car” means that part or appurtenance of a car at the maximum distance measured at right angles from the center line of the car. “Side clearance” means the shortest distance from the center line of track to a structure or obstruction at the side of track. “Width of a freight car” means twice the distance from the center line to the side of a car as defined in these regulations. Nothing in this chapter shall be construed as preventing the movement or distribution of material over tracks when that material is necessary in the construction or maintenance of the tracks, nor in the movement of special work equipment used in the construction, maintenance, or operation of the railroad, provided those movements shall be carried on under conditions reasonably necessary to provide for the safety of all concerned. If, in any particular case, exemption from any of the requirements of these regulations is deemed necessary by the carrier concerned, the Commission will consider the application of the carrier for the exemption when accompanied by a full statement of the conditions existing and the reason why the exemption is asked. An exemption so granted will be limited to the particular case covered by the application. The Commission reserves the right to modify any of the provisions of these regulations in specific cases when, in the Commission's opinion, public safety, convenience, or necessity would be served by so doing. The minimum overhead clearance above railroad tracks which are used or proposed to be used for transporting freight cars shall be 22 feet, except as otherwise provided in these regulations. Structures constructed before July 28, 1953 may be maintained at existing clearances and additional tracks may be constructed and existing tracks reconstructed under them at the same clearances. The overhead clearance above the top of the rail of tracks located at the entrance and inside of buildings may be reduced to 18 feet provided that: This clearance applies only to tracks terminating within the building; and When an overhead clearance of less than 22 feet exists on tracks inside the buildings, all cars, trains, motors, engines, or other equipment shall be brought to a stop before entering the buildings. The clearances provided in this regulation do not apply to the electric wires and equipment required over present and future tracks for the operation of trains by electric energy, provided the carriers concerned promulgate and enforce regulations that prohibit any employee from being on the top of cars while being operated under lower clearances than provided for in this regulation. The clearances provided in this regulation do not apply to engine houses, engine house facilities, tipples, or facilities used for the loading or unloading of bulk commodities. Minimum side clearances from the center line of tangent railroad tracks, which are used or proposed to be used for transporting freight cars, except as otherwise prescribed in these regulations, shall be as shown below. However, structures, including platforms and tracks, constructed before July 28, 1953, may be maintained and extended at the existing clearances. All structures and obstructions above the top of the rail except those specifically mentioned in these regulations are to have a minimum side clearance of 8 feet 6 inches. Platforms, except platforms adjacent to main or passing tracks 4 feet or less above the top of the rail, may have lesser clearances than 8 feet 6 inches from the center line of track on one side of the tracks only and where a full clearance of 8 feet 6 inches is maintained on the opposite side of the track or track centers to adjacent track are not less than 13 feet 6 inches. Platforms 4 feet 6 inches or less above the top of the rail when used principally for loading or unloading refrigerator cars may be constructed 8 feet from the center line of the track. Platforms previously constructed at clearances less than prescribed in these regulations may be extended at the lesser clearances unless the extension is in connection with the reconstruction of the original platform. Low passenger platforms not over 8 inches above the top of the rail may be 5 feet 1 inch from the center line of track. High passenger platforms not over 4 feet above the top of the rail may be 5 feet 7 inches from the center line of track. Side clearances, other than for platforms, on sidings only, at entrances to and inside of warehouse and industrial buildings shall be not less than 8 feet from the center line of track. Switchboxes, switch-operating mechanisms, and accessories necessary for the control and operation of signals and interlockers projecting 4 inches or less above the top of the rail shall be not less than 3 feet from the center line of track. The center spindle of signal and switch stands 3 feet or less above the top of the rail and located between tracks where not practicable to provide clearances otherwise prescribed in these regulations shall be not less than 6 feet from the center line of track. Through bridges supporting track affected, tunnels, water columns, and oil columns should be not less than 8 feet from the center line of track. The clearances for through bridges supporting track affected, water barrel platforms and refuge platforms on bridges and trestles not provided with walkways, handrails, water barrels, water columns, oil columns, block signals, cattle guards, and stock chutes when all or portions of them are 4 feet or less above the top of the rail, may be decreased to the extent defined by a line extending diagonally upward from a point level with the top of the rail and 5 feet distant laterally from the center line of track to a point 4 feet above the top of the rail and 8 feet distant laterally from the center line of track. However, the minimum clearance for handrails and water barrels on bridges with walkways shall be 7 feet 9 inches, and the minimum clearance for fences or cattle guards shall be 6 feet 9 inches. The lesser clearances authorized in §K, above, provided for handrails and water barrels, are not applicable to through bridges where the work of trainmen or yardmen require them to be upon the decks of the bridges for the purpose of coupling and uncoupling cars in the performance of switching service on a switching lead. The side clearances specified in these regulations do not apply to mail cranes during the times the arms of the mail cranes are supporting a mail sack for delivery, provided that the top arm is not then higher than 10 feet 8 inches above the top of the rail and neither arm extends to within 6 feet 5 inches from the center line of track. Icing platforms and supports shall have a minimum side clearance of 7 feet 8 inches. Operations over portions of track adjacent to icing platforms constructed before July 28, 1953 with a side clearance of less than 7 feet 8 inches shall be restricted except in emergencies to the movement or switching of trains containing refrigerator cars to be iced, and the necessary use of the tracks for the unloading of supplies required for the operation of the icing dock. Side clearances specified in these regulations do not apply to inter-track fences located on the center line between tracks. The clearances provided in this regulation do not apply to engine houses, engine house facilities, tipples, or facilities used for the loading or unloading of bulk commodities. All minimum side clearances prescribed in this regulation are for tangent tracks. Structures adjacent to curve tracks shall have an additional minimum side clearance compensating for the curvature. Clearances That May Be Decreased. The overhead and side clearances prescribed in these regulations may be decreased to the extent of a line extending diagonally downward from a point 4 feet from the center line of track 22 feet above the top of the rail to a point 8 feet 6 inches from the center line of track at 15 feet 3 inches above the top of the rail. For tracks located at entrances to and inside buildings with 18 feet overhead and 8 feet side clearance as prescribed in these regulations, the overhead and side clearances may be decreased to the extent of a line extending diagonally downward from a point 4 feet from the center line of track 18 feet above the top of the rail to a point 8 feet from the center line of track at 14 feet above the top of the rail. Canopies at one side of track at freight platforms may be constructed at not less than 4 feet from the center line of track provided: The height of it is at least 17 feet 6 inches above the top of the rail; and Either of the following apply: A full clearance of 8 feet 6 inches is maintained on the opposite side of the track from the canopy, or Track centers to adjacent track are not less than 13 feet 6 inches. The minimum distance between the center lines of parallel tracks shall be not less than 14 feet for main tracks and not less than 13 feet 6 inches for yard and side tracks except as otherwise provided in these regulations. The center line of any track, except a main track or a passing track, parallel and adjacent to a main track or a passing track, shall be at least 15 feet from the center line of the main track or passing track. However, where a passing track is adjacent to and at least 15 feet distant from the main track, any other track may be constructed adjacent to the passing track with clearance of not less than 13 feet 6 inches. The center line of any ladder track, constructed parallel to any other adjacent track, shall have a clearance of not less than 18 feet from the center line of the other track, except that parallel ladder tracks shall have a clearance of not less than 19 feet center line to center line. The minimum distance between the center lines of parallel team, house, and industry tracks shall be not less than 13 feet. Tracks constructed before July 28, 1953 may be extended without increasing distances between tracks. Merchandise, material, or other articles may not knowingly be permitted to remain piled or assembled on the ground or on platforms adjacent to any track at a distance less than 8 feet 6 inches from the center line of track. On industrial tracks the responsibility for compliance with this regulation shall rest with the industry. A suitable line or other marker should be maintained at a distance of 8 feet 6 inches from the center line of track, on all platforms, excluding passenger platforms, to indicate the space along the edge of the platform which must be kept clear of merchandise, material, or other articles. The space between tracks ordinarily used by train and yardmen and other employees as a walkway in the discharge of their duties and the space beside the tracks within 8 feet 6 inches of the center line of track shall be kept in a reasonably suitable condition for that purpose. Except as otherwise provided in these regulations, where the overhead or side clearances between a track and any building, structure, or facility are less than the minimum prescribed in these regulations, but were created before July 28, 1953, the minimum clearances prescribed in these regulations shall be provided whenever the building, structure, or facility is relocated or reconstructed. However, the Commission will consider specific requests for the future continuance of the prior clearances at the reconstructed building, structure, or facility when application for a continuance has been made as provided in Regulation .02B of this chapter. Except as provided in these regulations, a railroad corporation may not operate or permit to be operated any cars, trains, motors, engines, or other rolling equipment over its own tracks, or industrial sidings directly connected with its own tracks, or connected with its own tracks through other industrial sidings, on which overhead or side clearances, or clearances between tracks, are less than the minimum prescribed in these regulations, if the tracks or structures adjacent to the tracks are constructed or reconstructed subsequent to the effective date of these regulations by the railroad or by others where the railroad has the right to control the construction or reconstruction. These regulations do not constitute a finding by the Commission that compliance or noncompliance shall be determinative of the question of due care. Public Utilities Article, §§2-121, 5-101, and 9-401—9-403, Annotated Code of Maryland Effective date: July 28, 1953 (Order No. 50138)