In ECT ratings, which tag indicates propagation across the crack?

• A. ECTPV (Upon isolation)
• B. ECTN## (No prop fracture)
• C. ECTP## (Prop across ec)
• D. ECTX (No)

Answer: (C)

In ECT ratings, you’re evaluating whether a crack will grow under the test conditions. The key idea is whether propagation across the existing crack is possible. A tag that includes Prop and explicitly notes across the crack communicates that propagation can occur along the crack. That’s why the tag indicating Propagation across the crack is the best choice: it directly encodes that the fracture can extend across the crack, which is exactly what the question asks about. The other tags describe scenarios with no propagation or different conditions, so they don’t indicate propagation across the crack.