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Safety Recommendation Details

Safety Recommendation H-84-036
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 CONNECTICUT DEPARTMENT OF TRANSPORTATION: PREPARE INDIVIDUAL INSPECTION AND MAINTENANCE MANUALS FOR LARGE OR COMPLEX BRIDGES WITHIN CONNECTICUT.
Original recommendation transmittal letter: PDF
Overall Status: Closed - Acceptable Alternate 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: 3/14/1988
Addressee(s) and Addressee Status: State of Connecticut (Closed - Acceptable Alternate Action)
Keyword(s):

Safety Recommendation History
From: NTSB
To: State of Connecticut
Date: 3/14/1988
Response:

From: State of Connecticut
To: NTSB
Date: 12/17/1987
Response: ALL COMPLEX BRIDGES IN CONNECTICUT ARE NOW BEING INSPECTED BY PRIVATE CONSULTANT FIRMS UNDER THE DIRECTION OF A REGISTERED PROFESSIONAL ENGINEER. THEIR SCOPE OF WORK REQUIRES THEM TO MARK ON THE STRUCTURE PLANS ANY ITEM REQUIRING SPECIAL ATTENTION DURING FUTURE INSPECTIONS OF THE STRUCTURE AS WELL AS LOCATIONS OF DEFICIENCIES REQUIRING CORRECTIVE ACTION. IT IS OUR INTENT TO USE THESE PLANS IN LIEU OF SITE SPECIFIC MANUALS.

From: NTSB
To: State of Connecticut
Date: 10/26/1987
Response: The Safety Board's intent in issuing this recommendation is to insure that CONNDOT prepare inspection and maintenance manuals for all large or complex bridges within the State. We assume from Mr. Burns' response that private consulting engineering firms will now have the responsibility for developing these individual bridge inspection and maintenance manuals. Pending a further response on this aspect of bridge safety, this recommendation will be classified as "Open--Acceptable Action."

From: State of Connecticut
To: NTSB
Date: 8/6/1987
Response: ALL COMPLEX BRIDGES IN CONNECTICUT ARE NOW BEING INSPECTED BY PRIVATE CONSULTING ENGINEERING FIRMS UNDER THE DIRECTION OF A REGISTERED PROFESSIONAL ENGINEER.

From: NTSB
To: State of Connecticut
Date: 5/15/1987
Response: