Robustness

Graceful degradation is a close second to robustness.

Robustness was considered to be an essential feature because of the comparatively high starting effort and the generally rough work for which the locomotives are to be used.

The Inspecting Officer draws attention to the remarkable way in which the train held together after the final derailment; this was due in no small measure to the robustness of the buckeye couplings fitted to the coaches.