Case Study: Subcontractor Material Quality Issues Cause Rejection of Bridge Components in New York (2020)

Project Overview
• Name: Tappan Zee Bridge Replacement
• Location: New York
• Year: 2020
• Project Size: $3.9 billion
• Scope: Major bridge replacement with extensive prefabricated components
• Lead Agencies/Contractors: New York State Thruway Authority /

Category of the Issue, Problem, or Challenge
• Subcontractor Management
• Quality Control & Materials

Summary of the Issue, Problem, or Challenge
Steel components fabricated by a subcontractor failed to meet specified strength and dimensional tolerances, causing rejection and re-fabrication delays.

Root Cause Analysis

• Subcontractor lacked rigorous material testing during fabrication.
• Poor quality control oversight and documentation gaps.
• Inadequate training and skill levels among subcontractor fabrication workers.
• Weak communication of specifications and tolerances between prime and subcontractor.

Impacts Due to the Issue, Problem, or Challenge

• Rejection of fabricated components delayed erection by 2 months.
• Additional costs for re-fabrication and storage.
• Increased scrutiny and inspection requirements.

Corrective Actions Taken

1. Subcontractor implemented enhanced material testing and inspection protocols.
2. Prime contractor increased on-site QA/QC presence during fabrication.
3. Conducted joint training sessions on specifications and quality requirements.
4. Improved documentation and traceability systems.

Lessons Learned

• Subcontractor material quality directly impacts project timelines and costs.
• Strong QA/QC programs and training prevent rework and delays.
• Clear communication of specifications is critical.

Audit & Prevention: Project Control Questions to Ask on Future Projects to Help Control the Situation

• Are subcontractor QC procedures aligned with project specifications?
• Is material testing conducted regularly and documented?
• Are fabrication teams trained on quality requirements?