Subpart C

C. Track geometry

1. Scope

This subpart prescribes minimum requirements for the gauge, alignment, and surface of track and the elevation of the outer rails and speed limitations for curved track.

2. Gauge

• 2.1 Gauge is measured between the heads of the rails at right angles to the rails in a plane 5/8 inch below the top of the rail head.
• 2.2 Standard gauge is 56 ½ inches.
• 2.3 Gauge must be within the limits prescribed in the following table:

Class of track	The gauge must be at least	But not more than
Excepted track	N/A	58 1/4''
1	55 3/4''	58''
2	55 3/4''	57 ¾''
3	56''	57 ¾''
4 and 5	56''	57 ½''
Yard Track Category 1 & Category 2	55 ¾''	57 ¾''
Yard Track Category 3 & Category 4	55 ¾''	58''

• 2.4 Variation in Gauge
  When the gauge is less than 56 inches and the change in gauge over a distance of 20 feet (6.096 m) or less on either side of the defective location exceeds 1 ½ inches, train speed must be reduced according to Class 1 track speed.

3. Track Alignment

Alignment may not deviate from uniformity more than the amount prescribed in the following table:

Class of Track	Tangent Track	Curved Track
	The deviation of the mid- offset from a 62-foot lineFootnote 1 may not be more than-	The deviation of the mid-ordinate from a 31-foot chordFootnote 2 may not be more than-	The deviation of the mid-ordinate from a 62-foot chordFootnote 2 may not be more than-
1	5''	N/AFootnote 3	5''
2	3''	N/AFootnote 3	3''
3	1 3/4''	1 1/4''	1 3/4''
4	1 1/2''	1''	1 1/2''
5	3/4''	1/2''	5/8''

4. Curves: Elevation and Speed Limitations

• 4.1 The maximum cross level on the outside rail of a curve may not be more than 7 inches on any track. Curves exceeding 6 inches cross level must be monitored and have a remedial action plan to bring it back to 6 inches or less cross level. The outside rail of a curve may not be lower than the inside rail, except as per table in Part II, Subpart C section 6 Track Surface.
• 4.2 The maximum allowable operating speed for each curve is determined by the following formula:

where:

Vmax = Maximum allowable operating speed (miles per hour)
Ea = Actual elevation of the outside rail (inches)¹
d = Degree of curvature (degrees)²

1. For the purpose of calculating Vmax only, actual elevation for each 155 foot track segment in the body of the curve is determined by averaging the elevation for 10 points through the segment at 15.5-foot spacing. If the curve length is less than 155 ft, average the points through the full length of the body of the curve.
2. Degree of curvature is determined by averaging the degree of curvature over the same track segment as the elevation.

Below is a table of maximum allowable operating speed computed in accordance with this formula for various elevations and degrees of curvature.

Degree of Curvature	Three-Inch Unbalance
	Elevation in Inches
	0	1/2	1	1 ½	2	2 ½	3	3 ½	4	4 ½	5	5 ½	6
	Maximum allowable operating speed (m.p.h.)
0° 30'	93	100	107	113	120	125	131	136	141	146	151	156	160
1° 00'	66	71	76	80	85	89	93	96	100	104	107	110	113
1° 15'	59	63	68	72	76	79	83	86	89	93	96	99	101
1° 30'	54	58	62	66	69	72	76	79	82	85	87	90	93
1° 45'	50	54	57	61	64	67	70	73	76	78	81	83	86
2° 00'	46	50	54	57	60	63	66	68	71	73	76	78	80
2° 15'	44	47	50	54	56	59	62	64	67	69	71	74	76
2° 30'	41	45	48	51	54	56	59	61	63	66	68	70	72
2° 45'	40	43	46	48	51	54	56	58	60	62	65	66	68
3° 00'	38	41	44	46	49	51	54	56	58	60	62	64	66
3° 15'	36	39	42	45	47	49	51	54	56	57	59	61	63
3° 30'	35	38	40	43	45	47	50	52	54	55	57	59	61
3° 45'	34	37	39	41	44	46	48	50	52	54	55	57	59
4° 00'	33	35	38	40	42	44	46	48	50	52	54	55	57
4° 30'	31	33	36	38	40	42	44	45	47	49	50	52	54
5° 00'	29	32	34	36	38	40	41	43	45	46	48	49	51
5° 30'	28	30	32	34	36	38	40	41	43	44	46	47	48
6° 00'	27	29	31	33	35	36	38	39	41	42	44	45	46
6° 30'	26	28	30	31	33	35	36	38	39	41	42	43	45
7° 00'	25	27	29	30	32	34	35	36	38	39	40	42	43
8° 00'	23	25	27	28	30	31	33	34	35	37	38	39	40
9° 00'	22	24	25	27	28	30	31	32	33	35	36	37	38
10° 00'	21	22	24	25	27	28	29	31	32	33	34	35	36
11° 00'	20	21	23	24	26	27	28	29	30	31	32	33	34
12° 00'	19	20	22	23	24	26	27	28	29	30	31	32	33

• 4.3 A track owner or a railway company may request approval from Transport Canada to operate specified railway equipment at a level of cant deficiency greater than 3 inches.

5. Elevation of Curved Track: Runoff

• 5.1 If a curve is elevated, the full elevation must be provided throughout the curve, unless physical conditions do not permit. If elevation runoff occurs in a curve, the actual minimum elevation must be used in computing the maximum allowable operating speed for that curve under 4.2.
• 5.2 Elevation runoff must be at a uniform rate, within the limits of track surface deviation prescribed in Part II, Subpart C section 6 and it must extend at least the full length of the spirals. If physical conditions do not permit a spiral long enough to accommodate the minimum length of runoff, part of the runoff may be on tangent track.

6. Track Surface

• 6.1 Each owner of the track to which this part applies shall maintain the surface of its track within the limits prescribed in the following table:

Track Surface	Class of Track
	1	2	3	4	5
The runoff in any 31 ft of rail at the end of the raise may not be more than	3 ½''	3''	2''	1 ½''	1''
The deviation from uniform profile on either rail at the mid-ordinate of a 62 foot chord may not be more than	3''	2 ¾''	2 ¼''	2''	1 ¼''
The difference in cross level between any two points less than 31 ft apart on spirals may not be more than	2''	1 ¾''	1 ¼''	1''	¾''
The deviation from zero cross level at any point on tangent track or reverse cross level elevation on non tangent track may not be more than	3''	2''	1 ¾''	1 ¼''	1''
The difference in cross level between any two points less than 62 ft apart may not be more than	3''	2 ¼"	2''	1 ¾	1 ½''

• 6.2 To control harmonics on Class 2 through 5 jointed track with staggered joints, the cross level differences shall not exceed 1 ¼ inches in all of six consecutive pairs of joints, as created by 7 low joints. Track with joints staggered less than 10 feet (3.048 m) shall not be considered as having staggered joints. Joints within the 7 low joints outside of the regular joint spacing shall not be considered as joints for purposes of this subsection. For 79 or 80 foot long rails, this subsection is not applicable.

7. Remedial Action for Measurements by Electronic Geometry Inspection Vehicle

7.1 When a track geometry-related defect is detected during an electronic geometry inspection and communicated to the track supervisor prior to the next train movement:

1. For any deviation requiring a two class speed reduction, the railway company must immediately, upon notification to the track supervisor, comply with Part I, Subsection 6.2.
2. For any deviation requiring a one class speed reduction, the railway company may, for a period of seventy-two (72) hours after the inspection, use linear interpolation to determine the speed of the temporary slow order initiated to protect the defect. Records of slow orders imposed or reason for not imposing one must be maintained. Upon the expiration of the seventy-two (72) hours period, if the track defect has not been repaired, the slow order speed(s) must be revised to those of the next lower track Class.

7.2 When a track geometry-related defect is detected during an electronic geometry inspection and not communicated to the track supervisor prior to the next train movement:

1. Notwithstanding Part I Subsection 6.2, the railway company must ensure that the track supervisor is notified of track geometry-related defect, within 48 hours of the electronic geometry inspection vehicle inspecting the track.
2. For any deviation requiring a two class speed reduction, the railway company must immediately, upon notification to the track supervisor, comply with Part I, Subsection 6.2.
3. Notwithstanding Part I Subsection 6.2, for any deviation requiring a one class speed reduction, the railway company must within twenty-four (24) hours of notification to the track supervisor, bring the line of track into compliance.

8. Track Geometry Management Plan

8.1 Each railway company must develop and adhere to a Track Geometry Management Plan that:

1. defines a combination of track geometry conditions including:
   • Maximum spacing;
   • Combinations of track geometry conditions, which should include as a minimum:
     • For railway companies transporting covered hopper cars: Lateral alignment and deviation from uniform profile
     • For railway companies transporting tank cars: Lateral alignment and rate of change for cross level
   • Thresholds for the combinations of track geometry conditions, which must be lower than single defect thresholds as defined in Subpart C – Track Geometry; and
   • Requirements for remedial action(s) to be taken if the combination(s) of track geometry conditions exceeds thresholds as defined in the Track Geometry Management Plan.
2. Includes instructions for monitoring and taking appropriate measures for track geometry conditions approaching the limits prescribed under Part II Subpart C Sections 2, 3, and 6, at a minimum for key routes or tracks over which trains operate at Class 3 speed or higher.

8.2 Each railway company with a key route or track over which trains operate at Class 3 speed or higher must have the Track Geometry Management Plan approved by a professional engineer.

8.3 Each railway company must file a copy of their Track Geometry Management Plan with Transport Canada. Any subsequent revisions to the plan must be filed with Transport Canada before the revisions become effective.

8.4 Each railway company must maintain records, for a minimum of 1 year, to demonstrate that the requirements of the Track Geometry Management Plan are being adhered to.