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Safety Recommendation Details

Safety Recommendation H-84-051
Details
Synopsis: ON JUNE 28, 1983, A 100-FOOT-LONG SUSPENDED SPAN BETWEEN PIERS 20 AND 21 OF THE EASTBOUND TRAFFIC LANES OF THE INTERSTATE ROUTE 95 HIGHWAY BRIDGE OVER THE MIANUS RIVER IN GREENWICH, CONNECTICUT, COLLAPSED AND FELL 70 FEET INTO THE RIVER BELOW. TWO TRACTOR-SEMITRAILERS AND TWO AUTOMOBILES PLUNGED INTO THE VOID IN THE BRIDGE AND WERE DESTROYED BY IMPACT FROM THE FALL. THREE VEHICLE OCCUPANTS DIED, AND THE OTHER THREE RECEIVED SERIOUS INJURIES. THE NATIONAL TRANSPORTATION SAFETY BOARD DETERMINED THAT THE PROBABLE CAUSE OF THE COLLAPSE OF THE MIANUS RIVER BRIDGE SPAN WAS THE UNDETECTED LATERAL DISPLACEMENT OF THE HANGERS OF THE PIN AND HANGER SUSPENSION ASSEMBLY IN THE SOUTHEAST CORNER OF THE SPAN BY CORROSION-INDUCED FORCES DUE TO DEFICIENCIES IN THE STATE OF CONNECTICUT'S BRIDGE SAFETY INSPECTION AND BRIDGE MAINTENANCE PROGRAM.
Recommendation: THE NTSB RECOMMENDS THAT THE FEDERAL HIGHWAY ADMINISTRATION: PRESCRIBE CRITERIA FOR IN-DEPTH INSPECTIONS OF PIN AND HANGER ASSEMBLIES BASED ON OBJECTIVE MEASURES OF THE RISK OF HIDDEN DETERIORATION, SUCH AS THE TIME SINCE THE LAST INSPECTION, AND/OR WHETHER THE PIN AND HANGER ASSEMBLY IS DISMANTLED.
Original recommendation transmittal letter: PDF
Overall Status: Closed - Acceptable Action
Mode: Highway
Location: Mianus River, Greenwich, CT, United States
Is Reiterated: No
Is Hazmat: No
Is NPRM: No
Accident #: DCA83AH003
Accident Reports: Collapse of a Suspended Span of Inter- state Route 95 Highway Bridge over the Mianus River
Report #: HAR-84-03
Accident Date: 6/28/1983
Issue Date: 7/19/1984
Date Closed: 4/1/1988
Addressee(s) and Addressee Status: FHWA (Closed - Acceptable Action)
Keyword(s):

Safety Recommendation History
From: NTSB
To: FHWA
Date: 4/1/1988
Response:

From: FHWA
To: NTSB
Date: 1/5/1988
Response: COMPLETION OF THESE RECOMMENDATIONS IS DEPENDENT ON THE PUBLICATION OF TWO MANUALS: (1) "INSPECTION OF FRACTURE CRITICAL BRIDGE MEMBERS" (2) "CULVERT INSPECTOR'S TRAINING MANUAL." THE FIRST MANUAL WAS PUBLISHED IN SEPT. 1986 AND THE SECOND MANUAL WAS PUBLISHED IN JULY 1986. BOTH MANUALS ARE BEING USED IN TRAINING COURSES FOR BRIDGE INSPECTORS DEVELOPED BY THE NATIONAL HIGHWAY INSTITUTE FOR FHWA. WE BELIEVE THESE ACTIONS FULLY SATISFY THESE RECOMMENDATIONS.

From: NTSB
To: FHWA
Date: 3/19/1987
Response:

From: FHWA
To: NTSB
Date: 11/7/1986
Response: COMPLETION OF THESE RECOMMENDATIONS IS DEPENDENT ON THE PUBLICATION OF TWO MANUALS: (1) "INSPECTION OF FRACTURE CRITICAL BRIDGE MEMBERS" AND, (2) "CULVERT INSPECTOR'S TRAINING MANUAL." THE FIRST MANUAL IS IN THE FINAL REVIEW STAGE AND SHOULD BE PUBLISHED IN THE NEAR FUTURE. ATTACHED IS A COURSE ANNOUNCEMENT FOR THE FRACTURE CRITICAL BRIDGE MEMBER INSPECTION COURSE.

From: NTSB
To: FHWA
Date: 6/10/1985
Response:

From: FHWA
To: NTSB
Date: 11/9/1984
Response: FHWA LTR: THIS RECOMMENDATION WILL BE ACCOMMODATED IN THE NEW MANUAL, "INSPECTION OF FRACTURE CRITICAL BRIDGE MEMBERS," NOW UNDER DEVELOPMENT AS DESCRIBED IN H-84-40.