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.
CONTENTS I. FOREWORD 1 A. Photographs and Diagrams 4 II. SYNOPSIS 9 II. FACTS 10 A. Summary of Work Prior to October 1968 and Questions Which Remained Unresolved at That Time 10 1. Field Operations Completed as of October 1968 10 2. Laboratory Work Reported in Interim Report 11 3. Observed Facts and Witness Testimony Inadequately Explained at the Time of Interim Report 12 4. Logical Framework for the Conduct of the Investigation 13 B. Field Investigations Since September 1968 19 1. Further Examinations at Reassembly Site 19 a. Hanger connection at U13N 20 b. Cleavage fractures in hangers 20 c. Cleavage fracture in lower chord 20 d. Scars and deformations in Ohio tower 20 e. Presence of numerous cleavage fractures 21 2. Detailed Survey of the Extent of Corrosion on Eyebar Chain and Stiffening Trusses 22 3. Experimental Measurements on the St. Marys Bridge 23 a. Natural modes and frequencies 23 b. Dynamic response due to moving vehicle 23 c. Secondary effects in chain bent post and other members 23 d. Susceptibility of eyebar joints to rotation 24 e. Lateral distortions due to single lane loads 24 C. Laboratory Investigations Since September 1968 25 1. Laboratory Investigations at the National Bureau of Standards 25 a. Chemical and metallurgical examination of eyebar steel 25 b. Metallurgical and mechanical tests of eyebar steel 32 c. Fractographic and microprobe studies of fracture in eyebar No. 330 34 d. Chemical and mechanical tests of A7-24 steel 37 e. Examination of fracture in hanger U17N, part 12C 39 f. Examination of fracture in chord member L12-L13N 42 g. Rivet failures in joint U13N 42 h. Other NBS investigations 45
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.