Bridge Welding (D1.5) Endorsement - AASHTO/AWS D1.5M/D1.5
What the endorsement actually tests
D1.5 is the bridge welding code, and the endorsement exam is less about general welding metallurgy than about how the code assigns responsibility and how its rules change with member type. The candidate must be fluent in four concept clusters: (1) the fracture-critical member (FCM) designation and what it triggers; (2) welding procedure qualification, including prequalified joint details versus procedure qualification records (PQRs) and the supporting welding procedure specification (WPS); (3) welder and welding operator performance qualification, its essential variables, and continuity/requalification rules; (4) fabrication and inspection requirements - fit-up tolerances, minimum fillet sizes, weld profiles, NDT methods and acceptance criteria, and the shop/field distinction in inspection authority.
Traps that show up in questions
The most common trap is treating D1.5 like D1.1. Bridge rules are more restrictive: FCMs demand stricter toughness and inspection, and certain details prequalified under D1.1 are not automatically prequalified here. A second trap is confusing procedure qualification with performance qualification - one qualifies the process and joint detail, the other qualifies the person. A third is assuming a welder's qualification transfers between processes, positions, or thickness ranges without checking essential variables. A fourth is forgetting that the engineer's approval is required for certain substitutions and that the code's inspection acceptance criteria differ by NDT method and by whether the discontinuity is in FCM or non-FCM work.
Worked rule of thumb
When a question asks whether a welder may weld a given joint, run the three-question checklist in order: Is there a qualified WPS covering process, position, thickness, and joint detail? Is the welder qualified for that process and position, with current continuity? Does the member's FCM status add any extra requirement (toughness, inspection, or approval)? If all three are yes, the weld is permitted; if any is unknown, the answer is no until qualified. On thickness, remember that qualification ranges are not open-ended - a welder qualified on thin plate is not thereby qualified on heavy sections without the code's range extension.
Study habit
Read the code's definitions and qualification clauses rather than the commentary, and practice tracing a single weld from WPS to welder to inspection record.