Skip Ribbon Commands
Skip to main content
Safety Recommendation Details

Safety Recommendation H-84-035
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: REVISE BRIDGE INSPECTION FORM BRI 18 (ED.1-81) TO PROVIDE FOR THE RECORDING OF INFORMATION REGARDING: (1) SPECIFIED CRITICAL ELEMENTS WITH INDIVIDUAL RATINGS SUPPORTED BY A NARRATIVE EXPLANATION; (2) OBSERVATIONS AND MEASUREMENTS OF ALIGNMENT OF MEMBERS; AND (3) USE OF SPECIALIZED EQUIPMENT TO GAIN ACCESS TO THE BRIDGE AREA BEING INSPECTED OR THE REASONS WHY SPECIALIZED EQUIPMENT WAS NOT USED.
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: 3/14/1988
Addressee(s) and Addressee Status: State of Connecticut (Closed - Acceptable 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: ENCLOSED AS YOU REQUESTED IS A COPY OF THE LATEST BRIDGE DESIGN MANUAL. ALSO ENCLOSED ARE EXCERPTS FROM CONN'S BRIDGE INSPECTION MANUAL CONCERNING THE RECORDING OF MEMBER ALIGNMENT, OUR FORMS FOR MEASURING PIN AND HANGER ALIGNMENT, A REVISED BRI-18 INDICATING THE USE OF A SNOOPER AND PORTIONS OF GENERAL PLAN SHEETS INDICATING SPECIAL AREAS REQUIRING INSPECTION. THIS INFORMATION ADDRESSES RECOMMENDATION H-84-35 WHICH HAS BEEN CLASSIFIED AS OPEN- ACCEPTABLE ACTION.

From: NTSB
To: State of Connecticut
Date: 10/26/1987
Response: We understand that special forms, in addition to Bridge Inspection Form BRI 18 (Ed.1-81), have been developed and used to observe and measure the alignment of pin and hanger members. Furthermore, critical elements of bridges are being noted on contract plans. Based on this information, Safety Recommendation H-84-35 has been classified as "Open--Acceptable Action." We would appreciate receiving detailed information concerning the recording of designated critical element information, such as vertical displacement at the joint of the bridge backwall, on either a revised BRI 18 form or on the new form for the recording of member alignment.

From: State of Connecticut
To: NTSB
Date: 8/6/1987
Response: CRITICAL ELEMENTS OF BRIDGES ARE NOW BEING NOTED ON CONTRACT PLANS. SPECIAL FORMS FOR OBSERVING AND MEASURING THE ALIGNMENT OF PIN AND HANGER MEMBERS HAVE BEEN DEVELOPED AND MADE OPERATIONAL. INSPECTION FORMS HAVE STIPULATIONS FOR THOSE BRIDGES REQUIRING THE USE OF A SNOOPER AND REQUIRE THE INSPECTIONS TO CONFIRM THAT THE SPECIALIZED EQUIPMENT WAS IN FACT UTILIZED.

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