Section 408.10345. Design of manhole steps.

(1) An employer shall ensure that manhole steps installed on or after the effective date of this rule are in compliance with all of the following requirements:

(a)    The manhole steps shall be capable of withstanding, and remaining solidly secured after being subjected to, a separate application of a horizontal pull out load of 400 pounds (1,780 n), and a vertical load of 800 pounds (3,650 n).

(b)   The manhole steps shall be capable of sustaining the vertical test load without developing a permanent set of more than 1/2 of an inch  (12.7 mm).

(c)   The loads shall be applied over a width of 3 1/2 inches (8.9 cm) centered on the step and be applied at a uniform rate until the required load is reached.

(d)   There shall not be visible cracking or fracturing of the step or spalling of the concrete.

(2)    Step bolts and manhole steps shall be maintained in a safe condition and be visually inspected before each use.

(3)    Step bolts that are bent more than 15 degrees below the horizontal shall be removed and replaced with bolts that are in compliance with the requirements of these rules. A manhole step that is bent to an extent that reduces the step's projection from the wall to less than 4 inches (1.1 cm) shall be removed and replaced with a step that is in compliance with the requirements of these rules or replaced with a climbing device that is in compliance with the requirements of this rule.

History: 1994 AACS.