Pin and hanger failures due to pack rust, leading to the introduction of hands-on requirements, occurred on which bridge?

• A. Eye Bolt Failure
• B. Silver Bridge
• C. Mianus River Bridge
• D. Daniel W. Hoan Bridge

Answer: (C)

Pin-and-hanger corrosion weakens the joint by rusting the packing around the pin, which can steal load transfer capacity and lead to sudden failure. The Mianus River Bridge collapse in 1983 was caused by such deterioration in pin-and-hanger connections, which highlighted the need for hands-on, physical inspection practices to reliably assess these critical components. This event prompted the adoption of hands-on inspection requirements to ensure inspectors actively verify the condition of these assemblies, not just rely on visual checks. The other options involve different failure modes or bridges not connected to this specific rust-related issue and the change in inspection approach.