Case Study: Subcontractor Equipment Failure Causes Delay on California Tunnel Project (2019)

Project Overview
• Name: San Francisco Bay Tunnel Project
• Location: San Francisco, California
• Year: 2019
• Project Size: $600 million
• Scope: Tunnel boring and excavation works
• Lead Agencies/Contractors: California DOT /

Category of the Issue, Problem, or Challenge
• Subcontractor Management
• Equipment Reliability & Maintenance

Summary of the Issue, Problem, or Challenge
Failure of subcontractor-owned tunnel boring machine components led to a 6-week stoppage for repairs, affecting overall project schedule.

Root Cause Analysis

• Inadequate maintenance and inspection routines by subcontractor.
• Delayed replacement of worn critical components.
• Insufficient spare parts inventory and logistics planning.
• Poor communication of equipment status between subcontractor and prime contractor.

Impacts Due to the Issue, Problem, or Challenge

• Prolonged downtime impacting excavation progress.
• Increased repair and demobilization costs.
• Schedule risk exposure and potential penalties.

Corrective Actions Taken

1. Instituted comprehensive preventive maintenance plans.
2. Improved spare parts management and supplier coordination.
3. Enhanced reporting and communication protocols on equipment health.
4. Conducted joint equipment status reviews regularly.

Lessons Learned

• Equipment reliability directly affects heavy civil project schedules.
• Preventive maintenance and spare parts readiness are essential.
• Transparent communication avoids surprises and enables rapid responses.

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

• Does subcontractor follow rigorous equipment maintenance protocols?
• Are spare parts and repair resources readily available?
• Is equipment status communicated proactively and clearly?