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Safety Recommendation Details

Safety Recommendation H-84-047
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: AUGMENT THE CURRENT INVENTORY AND RATING METHODOLOGY OF THE NATIONAL BRIDGE INSPECTION STANDARDS, WHICH EMPHASIZES AN OVERALL RATING FOR PLANNING LARGE-SCALE REPLACEMENT OR REHABILITATION FUNDING, TO REQUIRE INSPECTIONS AND RATINGS OF SUFFICIENT DEPTH AND DETAIL TO ADDRESS ALL ELEMENTS CRITICAL TO SAFETY.
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: 7/27/1989
Addressee(s) and Addressee Status: FHWA (Closed - Acceptable Action)
Keyword(s):

Safety Recommendation History
From: NTSB
To: FHWA
Date: 7/27/1989
Response:

From: FHWA
To: NTSB
Date: 5/11/1989
Response: WE BELIEVE THE REVISED NATIONAL BRIDGE INSPECTION STANDARDS, EFFECTIVE OCTOBER 25, 1988, AND FEDERAL-AID HIGHWAY PROGRAM MANUAL 6-7-2-1, EFFECTIVE FEBRUARY 21, 1989 (COPIES ENCLOSED) ADDRESS SAFETY RECOMMENDATIONS H-84-41,-46,-47. WE RESPECTFULLY REQUEST THESE RECOMMENDATIONS BE CLOSED.

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

From: FHWA
To: NTSB
Date: 11/7/1986
Response: THE NBIS WERE DEVELOPED TO ESTABLISH GENERAL INSPECTION, INVENTORY, RECORDING AND RATING CRITERIA AND MINIMUM INSPECTOR QUALIFICATION REQUIREMENTS. THE NBIS REFER TO THE AASHTO, "MANUAL FOR MAINTENANCE INSPECTION OF BRIDGES," WHICH PROVIDES DESCRIPTIONS AND PROCEDURES TO PROVIDE DETAILED OR INDEPTH BRIDGE INSPECTIONS. WHEN COMBINED WITH THE SOON TO BE PUBLISHED MANUAL, "INSPECTION OF FRACTURE CRITICAL BRIDGE MEMBERS," AND THE FORTHCOMING CHANGES IN THE NATIONAL BRIDGE INSPECTION STANDARDS, THE CURRENTLY AVAILABLE INFORMATION WILL BE MORE THAN SUFFICIENT TO PROVIDE BRIDGE INSPECTION GUIDANCE TO ALL RESPONSIBLE PARTIES.

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

From: FHWA
To: NTSB
Date: 11/9/1984
Response: FHWA LTR: THE NBIS REQUIRES THE INSPECTIONS AND RATINGS IN SUFFICIENT DEPTH AND DETAIL TO ADDRESS ALL ELEMENTS CRITICAL TO BRIDGE SAFETY. THE DEPTH AND DEGREE OF INSPECTION REQUIRED IS PROPERLY LEFT TO THE INDIVIDUAL IN CHARGE OF THE INSPECTION PROGRAM.