OOSC, Part II, Item 2. Coupling Devices, b. (5) Any Welds or Parent Metal Cracked

Although item 2.b.(5) in part II of the North American Standard Out-of-Service Criteria (OOSC) identifies any cracked welds or parent metal as being an out-of service defect, the note in association with this defect appears more restrictive. It refers to repair welds, well-defined cracks in stress or load bearing areas or cracks through 20 percent or more original welds or parent metal. The note associated with the section needs to be clarified.

When attempting to use the section to enforce an OOS condition, the language appears initially to prohibit any cracks in welds or parent metal. The note associated with this section appears to restrict the previous criteria to 20% or more of the original welds or parent metal. The determination of a crack of 20 percent needs to include how the total size of the parent metal/original weld is determined. Would an 8 inch crack in length of a 40 inch length upper coupler plate (20 percent) be considered OOS or would the width of the crack as well as the width of the coupler plate also need to be considered? Additionally, would a well-defined crack in the parent metal of a load bearing area be considered as OOS without regard to the 20 percent criteria? Clarification of the intent of item 2.b.(5) as well as detail on terms used such as parent metal?s original size dimension/determination is needed.

The intent of the note in this section needs to be clarified to avoid misinterpretation and improper enforcement. It appears the note should be incorporated into 2.b. 5) as follows: Item 2: Coupling Devices (b): Upper Coupler Assembly (5): Defective Welds / Parent Metal(i.) Repair weld with any crack (ii.) Parent metal with well-defined (especially open) cracks in stress or load bearing areas (iii.) Original welds cracked 20 percent or more* (iv.) Parent metal cracked 20 percent or more **Note: The measurement for calculation of the 20 percent criteria of original welds or parent metal shall be taken of the total length of the material which contains the crack in the same direction as the crack. The same note in question also appears in 2.a.(1)(c), 2.a.(2)(b), and 2.a.(5) which may also need to be adjusted to ensure uniformity.