To Preserve Evidence for an Accident Investigation

You'll Regret not doing these things immediately after an Accident.

1. Document position of Valves at, and upstream of, accident scene before they're moved and/or before people forget where they were positioned prior to securing the Accident Scene. (Investigators, both amateur and professional, will want to move valve handles to find out if they're full closed or full open. Once they're moved, that information is compromised). Don't forget to document positions of the smaller valves like those isolating the traps. These can be critical. Take a photo with date stamp of the valve handle and stem position with enough background to identify the valve when forensic engineers look at it years after the accident (when law suits and insurance claims are being resolved).

• In one accident in 2006, I noticed a 3/4"valve from a steam trap was closed, but it wasn't until 2010 that I noticed in a photo taken the day of my site visit that another 3/4" valve controlling steam to the condensate mover was off too. These "finds" proved to me that the start-up contractor who was suing the owner didn't know what they were doing. Thousands of pictures of the gasket that blew out were taken, but very few of the closed 3/4" valves that broke open the case.

2. Get written statements right away from each operator and witness in their own hand writing of what happened including conditions prior to the Accident, if they have knowledge of them. They should list their name and job title, what time they came to work, and start out with where they were and at what time they heard/saw/were told what happened. They might sketch a diagram or floor plan if that helps their explanation.

Their statements do not need to be elaborate or typed. Later on, the witnesses can be interviewed to flesh out their statements, but you want to get the details down before they are mis-remembered (which, trust me, they will be). Ask them to turn in the statements the next day. It takes less than a week for critical details to change in stories of what was seen and done.

• I recommend you explain that these statements are voluntary and solely for the purpose of figuring out what went wrong, not about casting blame, and that you follow this policy. The path to minimizing investigation and correction costs at this point is to encourage everyone to be truthful and appreciate those who are truthful for the courage it can take to admit a possible mistake.

3. Photograph site in detail before changing or moving anything. It helps to include a person or a hand in the photograph pointing to whatever is the focus of the photo. It gives scale and orientation. Turn the date and time function feature of your camera on to include these in each photo. Label the photos identifying the primary focus of the Picture. Later photos, after changes are made, must be distinguishable from after-accident photos.

4. Record the amount of condensate drained. If valves are opened, catch and measure the condensate that drains out. It's important to know where lots of condensate built up.

5. Develop a Time Line of Events culminating in the Accident. Try to nail down the exact time of the Accident and what events preceded it so there is a time line of the events that culminated in the accident. I've found this to always be necessary in figuring out what caused a steam accident.

6. Collect steam pressure and flow charts or recordings from the Boiler Plant and any metering that may show steam conditions leading up to the event.

7. Find "elevation" drawings showing the slope of piping to and away from the Accident site. These drawings, while you may think they don't exist, are virtually always in the original Engineering Drawing Set or Contractor Shop Drawings set from which the site was built. (It's the engineer's responsibility to tell a Contractor how to pitch the pipes to drain condensate. Somehow, this info must be conveyed to the Contractor.) If it's a water hammer accident, I'll need to find out where the condensate collected and that requires elevation drawings. (If you don't have the elevation drawings, get out the surveying equipment or hire a firm to survey the line).

This list is not supposed to replace those measures an attorney might recommend, such as isolating the Accident Scene to preserve evidence. These suggestions are based on my experience investigating steam accidents and the pain of reading depositions taken well after an accident to try to decipher what the @*&#! happened.

W. Kirsner, 26 June 2009, updated Mar 2013