Tank Car Head Puncture Mechanisms

摘要

In a number of railroad accidents the shell heads of hazardous material tank cars have been punctured. This report is concerned with the description and analysis of head puncture mechanisms. Three classification yard accidents and one main line accident were studied in detail, train-to-train collision tests were analyzed and the results of impact experiments were evaluated. The main conclusion of the report is that head puncture in classification yards is invariably due to overspeed impact. Such accidents can be prevented either by providing some fail-safe control for keeping impact speeds below 8 mph or, if impact speeds cannot be kept below 8 mph, not humping or flat switching more than one hazardous material tank car, or cars following it, onto any one track and requiring tank car heads to be designed or retrofitted to absorb a minimum amount of impact energy to be specified on the basis of further experiments and analytical studies recommended in this report.