That’s a view of the wreckage of the excursion steamer General Slocum, run aground in the Bronx after burning in the East River. Over 1000 people died during that incident, so I think it’s safe to say the ship was not safe.
I recently came across the definition of an essentially contested concept, and I think it’s quite useful. The short version is that an essentially contested concept is one where everyone agrees the topic is important but cannot, for reasons related to how they address the topic, ever agree on what not means. “Safety,” in the engineering sense, is such a concept.
An unsafe building – or ship – is easy to identify. It has failed in manner that threatens harm or it it is a condition where such failure is imminent. So far, so good. What’s the inverse of that? What’s safe?
Using the Slocum as an example, the deadly failure of the ship was the result of numerous causes including improper storage of flammable material, life-preservers in a deteriorated condition that were more likely to encourage people to sink than to float, fire hoses in a deteriorated condition, and portholes too small for adults to fit through. No one of those causes by itself resulted in the high death toll. In 1904, no one thought that small porthole windows were a problem, and there were no specific mandated tests for the usefulness of life preservers and fire houses on board a ship. Had there been such tests, the poor condition of the safety equipment would have been discovered; as it was the captain and the company that owned the ship were blamed but regulations had to be changed to actually prevent a recurrence of the event. This sequence played out again eight years later with the Titanic disaster and the associated lack of life boats, lack of life boat drill, and inadequate water-tight subdivision of large ships.
It is difficult to ever say something is safe, because the models that we use in design are simplified versions of reality. If we simplify by omitting a possible loading scenario which then occurs, we may have designed a building that is unsafe and collapses. Since all models are simpler than reality, we are always omitting something. Worse still, when we’re talking about existing buildings, there’s always something wrong somewhere, so we have to decide if the damage we’re seeing is minor and unimportant or potentially life-threatening. There’s no statement of safety for an existing building that doesn’t involve judgement to some degree. We can’t simply retreat into the comfort of codes and numbers because they won’t give us an answer.
The situation is not symmetrical. “Unsafety” is easily defined and not easily contested. “Safety” cannot be defined in the negative as simply “a lack of unsafe conditions” because we may not know what’s unsafe until it fails. (See the Slocum’s portholes or the Titanic’s watertight bulkheads.) Safety can’t be easily defined in a positive sense because too much judgement is required, hence my current fascination with essentially contested concepts. And with that, I’ve come full circle in this blog post.
Stay safe…
You must be logged in to post a comment.