Conn. Agencies Regs. § 13b-17-168
The clearances for (a) water barrel platforms and refuge platforms on bridges and trestles not provided with walkways, (b) handrails, (c) water barrels, (d) water columns, (e) oil columns, (f) cattle guards and (g) stock chutes, when all or portions thereof are four 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 five feet distant laterally from the center line of track to a point four feet above the top of the rail and eight feet distant laterally from the center line of track; provided the minimum clearance for handrails and water barrels on bridges with walkways shall be seven feet, nine inches, and provided the minimum clearance for fences of cattle guards shall be six feet, nine inches.
Conn. Agencies Regs. § 13b-17-168