Case Study: Quality Control Breakdown in Structural Steel Fabrication on Boston Tunnel Project (Massachusetts, 2018)

Project Overview
• Name: Boston Big Dig Phase II
• Location: Boston, Massachusetts
• Year: 2018
• Project Size: $1.1 billion
• Scope: Tunnel structural steel fabrication and erection
• Lead Agencies/Contractors: Massachusetts Department of Transportation (MassDOT) /

Category of the Issue, Problem, or Challenge
• Quality Control
• Structural

Summary of the Issue, Problem, or Challenge
Improper dimensional tolerances and weld defects in structural steel components resulted in on-site modifications and delays.

Root Cause Analysis

• Insufficient shop floor inspections and QC during fabrication.
• Poor adherence to welding procedures and specifications.
• Lack of third-party quality audits during fabrication.
• Communication gaps between fabrication shop and field erection teams.

Impacts Due to the Issue, Problem, or Challenge

• Delay of 4 months due to rework and field modifications.
• Increased costs from labor and fabrication corrections.
• Potential safety risks if defects were undetected.

Corrective Actions Taken

1. Enhanced shop floor QC with increased inspection frequency.
2. Strict enforcement and documentation of welding procedures.
3. Engaged independent third-party quality auditors.
4. Improved communication protocols between fabrication and erection teams.

Lessons Learned

• Dimensional accuracy is vital for structural steel fit-up.
• Continuous QC during fabrication prevents costly field issues.
• Independent audits add valuable oversight.

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

• Are shop floor inspections frequent and thorough?
• Are welding procedures strictly followed and documented?
• Are third-party audits integrated into fabrication QC?