Authors: Marek Benda, Avneesh Chandra, Signe Janoska-Bedi, Jamey Kane, and Jonny Vannucci. Spring 2019.

We collected nearly 500 data points on 226 individual submarines from six countries, relying on open source academic articles, source books, reports from watchdog groups, and news media. For each data point, we gathered information on submarine class and owner-country, as well as the complement — the number of sailors and officers — on board each submarine at the time of each case. We recorded the armaments — the type and number of weapons — on board each submarine. In addition, we developed a Class Faultiness Index to determine whether any classes were more subject to failures, given their service periods and class strength.