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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.
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of transgranular crack propagation. It is possible that the minor fatigue action upset the normal preference of the stress-corrosion mechanism for attack along the grain boundaries by creating localized slip planes also susceptible to such attack, but this might be considered a speculation.
## D. Compatibility of Established Mechanism of Failure with Observed Facts and Witness Testimony
The arguments in favor of considering the fracture in eyebar No. 330 as the event which initiated the collapse have thus far been derived from fractographic and metallurgical evidence, together with analytical determination of stress levels and conditions at the time of collapse. Other fractures have been eliminated as initiating events by similar evidence. There remains the question as to whether a failure sequence beginning with the fracture in eyebar No. 330 is compatible with facts derived from the general nature of damage observed in the wreckage, the position in which the wreckage fell, and the observations of witnesses.
This section describes what is believed to be the sequence of events during the collapse of the Point Pleasant Bridge, cites those observed facts which support this sequence, and interprets the statements of witnesses in relation to this assumed sequence. The detailed studies of distortions, the directions of loadings which appear to have caused these distortions, the fracture of various connections and the scars and other impact damage in the structure upon which this analysis is based come from many sources, but most extensively from the reports of R. A. Hechtman and Associates (References 8 through 14) and the field notes on the examination of wreckage prepared by the J. E. Greiner Company (Reference 35).
1. It is helpful first to consider the deformations which existed in the structure just prior to collapse, as developed in the computer analysis prepared by the Bridge Design Review and History working group. Using the data on distortions in the structures produced by live load at the time of the collapse and a temperature change for a $ 36^{\circ} \mathrm{F} $ drop from $ 68^{\circ} \mathrm{F} $ , the following conditions appear to have existed. The Ohio tower was essentially vertical due to the fact that the westward movement of its top produced by thermal contraction of the chain was almost exactly compensated for by the eastward movement produced by the live loading. The West Virginia tower was displaced slightly to the west at its top, probably on the order of one or two inches. The Ohio side span was deflected vertically at panel point 7 about 0.11" (0.71" downward due to loading and 0.60" upward due to temperature). This distortion of the side span produced a slight westward movement of the pin at panel point 0 in the slot of the chain bent post. Computations show a westward movement of 0.53" due to loading, but because of a 0.34" eastward movement as a result of the temperature drop, the net movement is 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.