Original Version
Rule 77.4
77.4 Clearances
The basic minimum clearances for trolley span wires are specified in Table 1, Column C and in Table 2, Column A. Modifications of these basic clearances are specified in Rules 37 and 38 and by the following provisions:
A. Above Railways
The minimum
vertical clearance of 19 feet above rails for trolley span
wires (Table 1, Case 2, Column C) applies only to those railways which do not
transport or propose to transport freight cars.
This minimum clearance shall be not less than 22 1/2 feet where the railway involved does
transport or proposes to transport freight cars.
B. Under Bridges, Etc.
A reduction of the clearances given in Table 1
to a clearance of not less than 14 feet above the rails is permitted for trolley
span wires under bridges, in tunnels, or in subways, and for 0 - 750 volt
conductors within exclusive and semi–exclusive rights–of–way as defined by
Alignment Classification 9.04–a. and 9.04–b.(1), contained in General Order No.
143–A , “Safety Rules and Regulations Governing
Light–Rail Transit”, provided the railway does not transport freight cars where
the vertical distance from the top of car or load to trolley contact conductor
is less than 6 feet. The grading of the level of trolley span wires from the
basic clearance to this reduced clearance is permitted at approaches to bridges,
tunnels, or subways.
C. From Conductors
The clearances of trolley span wires from conductors shall be as
specified in Table 2, Column A , except as modified
by the provisions of Rules 74.4–G and 78 .
D. From Guys or Span Wires
The clearance specified in Table 2, Case 1, Column A (18 inches) is not required between trolley span wires, backbones,
messengers, and similar wires or cables, used to support trolley contact
conductors and appurtenances.
E. From Poles and Crossarms
The clearances specified in Table 1, Column C, Cases 8 and 9 , are not intended to apply to insulated (unenergized) portions of
span wires, backbones, messengers, pull–offs and similar equipment at the poles
to which they are attached.
Strikeout and Underline Version
Rule 77.4
77.4 Clearances
The basic minimum
clearances for trolley span wires are specified in Table 1, Column C and
in Table 2, Column A. Modifications of
these basic clearances are specified in Rules 37 and 38 and by the following
provisions:
A. Above Railways
The minimum
vertical clearance of 22.5 19 feet above rails for trolley span
wires (Table 1, Case 2, Column C) may applies only to those railways which do not
transport or propose to transport freight cars.
This minimum clearance shall be decreased to 19 not less than 22 1/2 feet where the railway involved does not
transport nor proposes to transport freight cars.
B. Under Bridges, Etc.
A reduction of the clearances given in Table 1
to a clearance of not less than 14 feet above the rails is permitted for trolley
span wires under bridges, in tunnels, or in subways, and for 0 - 750 volt
conductors within exclusive and semi–exclusive rights–of–way as defined by
Alignment Classification 9.04–a. and 9.04–b.(1), contained in General Order No.
143–A , “Safety Rules and Regulations Governing
Light–Rail Transit”, provided the railway does not transport freight cars where
the vertical distance from the top of car or load to trolley contact conductor
is less than 6 feet. The grading of the level of trolley span wires from the
basic clearance to this reduced clearance is permitted at approaches to bridges,
tunnels, or subways.
C. From Conductors
The clearances of trolley span wires from conductors shall be as
specified in Table 2, Column A , except as modified
by the provisions of Rules 74.4–G and 78 .
D. From Guys or Span Wires
The clearance specified in Table 2, Case 1, Column A (18 inches) is not required between trolley span wires, backbones,
messengers, and similar wires or cables, used to support trolley contact
conductors and appurtenances.
E. From Poles and Crossarms
The clearances specified in Table 1, Column C, Cases 8 and 9 , are not intended to apply to insulated (unenergized) portions of
span wires, backbones, messengers, pull–offs and similar equipment at the poles
to which they are attached.
Final Version
Rule 77.4
77.4 Clearances
The basic clearances for trolley span wires are specified in Table 1, Column C and inTable 2, Column A. Modifications of these basic clearances are specified in Rules 37 and 38 and by the following provisions:
A. Above Railways
The
vertical clearance of 22.5 feet above rails for trolley span
wires (Table 1, Case 2, Column C) may be decreased to 19 feet where the railway involved does not
transport nor proposes to transport freight cars.
B. Under Bridges, ETC
A reduction of the clearance given in Table 1 to a clearance of not less than 14 feet above rails is permitted for trolley span wires under bridges, in tunnels, or in subways, and for 0 - 750 volt conductors within exclusive and semi–exclusive rights–of–way as defined by Alignment Classification 9.04–a. and 9.04–b.(1), contained in General Order No. 143–A , “Safety Rules and Regulations Governing Light–Rail Transit”, provided the railways does not transport freight cars where the vertical distance from the top of car or load to trolley contact conductor is less than 6 feet. The grading of the level of trolley span wires from the basic clearance to this reduced clearance is permitted at approaches to bridges, tunnels, or subways.
C. From Conductors
The clearances of trolley span wires from conductors shall be as specified in Table 2, Column A, except as modified by the provisions of Rules 74.4-G and 78.
D. From Guys or Span Wires
The clearance specified in Table 2, Case, Column A (18 inches) is not required between trolley span wires, backbones, messengers, and similar wires or cables, used to support trolley contact conductors and appurtenances.
E. From Poles and Crossarms
The clearances specified in Table 1, Column C, Cases 8 and 9, are not intended to apply insulated (unenergized) portions of span wires, backbones, messengers, pulloffs and similar equipment at the poles to which they are attached.