Documents / Document
This is the final highway accident report (NTSB-HAR-71-1) from the National Transportation Safety Board, adopted in December 1970. It covers the collapse of the U.S. 35 bridge between Point Pleasant, West Virginia, and Kanauga, Ohio, on December 15, 1967, which killed 46 people. The Board found that the cause was a cleavage fracture in eyebar 330 at joint C13N. That fracture grew from a flaw produced over 40 years by stress corrosion and corrosion fatigue, in a spot that could not be seen or found by inspection.
Read from the scan by GLM-OCR; expect the odd misread word.
NATIONAL TRANSPORTATION SAFETY BOARD WASHINGTON, D. C. 20591 HIGHWAY ACCIDENT REPORT Adopted: December 15, 1970 COLLAPSE OF U. S. 35 HIGHWAY BRIDGE POINT PLEASANT, WEST VIRGINIA DECEMBER 15, 1967 ## I. FOREWORD This final report by the National Transportation Safety Board supplements the interim report issued October 4, 1968, entitled "Collapse of U. S. 35 Highway Bridge, Point Pleasant, West Virginia, December 15, 1967," File SS-H-2. The interim report included descriptions of the design, construction, operation, and maintenance of the bridge from its completion in 1928 until its collapse in 1967. Detailed descriptions of the collapse of the bridge were given in the interim report, based upon documentary evidence and witness testimony as presented at the Safety Board's public hearing held in Charleston, West Virginia, May 10 through May 13, inclusive, 1968. As stated in the interim report, it was determined that the fracture in suspension chain eyebar 330 (north bar, north chain, Ohio side span) was essential to the catastrophic stage of the collapse, but the cause of the fracture had not been determined. Eyebar 330 and its sister eyebar 33 were located in the north suspension chain of the bridge between joints C11 and C13. C13 was the first joint west of the Ohio tower. The north leg of the Ohio tower was joint C15N. The fracture occurred in the lower half of the head of eyebar 330 in joint C13N. The line of this cleavage fracture was at right angles to the axis of eyebar 330. Then a ductile fracture on the opposite side of the eye from the cleavage fracture resulted in the complete separation of eyebar 330 from joint C13N. It was established that eyebar 33 had slipped from the eyebar pin at joint C13N at some time during the separation of the north eyebar chain at joint C13N. It was not known at the time of issuance of the interim report whether the fractures in eyebar 330 preceded the separation of eyebar 33 from the pin. When the north eyebar chain was separated at joint C13N, total collapse of the bridge was a certainty due to its design with the towers resting on rocker seats. Prior to issue of the interim report, the Safety Board's Structural Analysis and Tests Group of the investigative team began supervision of an extensive series of field and laboratory examinations to determine the mechanism of failure and the cause of the fracture at joint C13N. Those examinations were completed in the fall of 1970. The Safety Board issued a press release on December 31, 1968, describing the discovery during laboratory examinations of evidence of a series of minute cracks penetrating to the interior of the fractured head of eyebar 330. It was stated that stress corrosion was suspected
Document, cited by the archive. The PDF is mirrored here; the original link is above. The text was read from the page images by GLM-OCR; expect the odd misread word. 202 pages are in the text index: search them above, or from the library's search.