Can you “calibrate” a forensic expert?

What happens when we calibrate something, and can the procedure apply to a person?  For example, a forensic expert?  Does it happen unbeknownst to an expert?

I said in a recent blog that this happens to an expert when he visually examines the site of a failure or accident in the built environment – he gets calibrated to the site. (Ref. 1)

Then I began to think about it.

This description of a visual examination came to me when I remembered hearing years ago about an American engineer asking to have some pits dug at a site that he was visually examining in Newfoundland, so he could “…get calibrated to the site”.  The phrase resonated with me at the time.

This was George F. Sowers, a professional engineer with an international reputation in foundation and geotechnical engineering. (Ref. 2)  All of us in this field of practice knew of him.  This was a serious foundation problem if Dr. Sowers was called in.

Still, I thought, I better check the meaning of calibrate in the event Dr. Sowers stretched it a little.

The Merriam-Webster dictionary gives several definitions of calibrate, one of the last in a list of five is most applicable to Sowers use of the word:

“…to adjust precisely for a particular function, e.g., calibrate a thermometer”

Sowers was getting himself adjusted precisely to the site so he could function in a particular way – as the forensic engineer investigating the cause of the problem at this particular site.

You might say this is wandering away from a dictionary’s meaning. (Ref. 3)  I don’t think so.  One thing I’ve learned blogging on the nature and methods of forensic engineering in the past eight years is that words are taking on new shades of meaning all the time.

Using the word calibrate in a recent blog to describe what happens during a visual site assessment just came out of me from deep down inside.  It was natural.  Also knowing it was used this way by a quite reputable and experienced engineer years ago.  And it’s supported by Merriam-Webster.

The word calibrate does suggest preciseness, and that’s a big element in a visual assessment of a site – you can’t plan a forensic investigation of a failure or accident until you’ve seen the site.  Think, a picture (seeing something) is worth a 1,000 words.


Can you “calibrate” a forensic expert?  Yes.  It happens as a matter of course when s/he does a visual assessment of a site before commenting on how to determine the cause of the accident or failure, if more investigation seems necessary.  And a degree of expert calibration occurs when s/he does a virtual visual assessment.


  1. COVID-19 and an initial forensic task aka a visual site assessment, sans social distancing.  Posted June 1, 2020
  2. Sowers, George F., Introductory Soil Mechanics and Foundations: Geotechnical Engineering, 4th edition, MacMillan Publishing Co., Inc, New York
  3. Family Word Finder, A New Thesaurus of Synonyms and Antonyms in Dictionary Form, 896 pg. Reader’s Digest in association with Stuart B. Flexner 1975

(Posted by Eric E. Jorden, M.Sc., P.Eng. Consulting Professional Engineer, Forensic Engineer, Geotechnology Ltd., Halifax, Nova Scotia, Canada   

Conferring on video with apps like Zoom: Another forensic tool

Video conferencing with apps like Zoom makes it even easier to push back against COVID-19 and do the right thing at the start of a forensic investigation.  That is, get on site quick-smart after a failure or accident and do a visual assessment.

An app like Zoom comes into the picture when the forensic expert is briefed on the incident during a video conference.  And what a marvelous way to get briefed – sitting in a bright and colourful virtual meeting room.

Microsoft Teams (‘Teams’) and Go To Meeting are two other video tools making life easier and cost effective.


I knew about Zoom but only just.  I learned more last Wednesday evening (June 3) when I took part in a virtual meeting with members of CATAIR, the Canadian Association of Technical Accident Investigators and Reconstructionists.  Of course it was like sitting and meeting in the same room as many of you know.

CATAIR provides accident investigators a professional and affordable way to meet and share experiences and ideas.  The association consists of serving and former police officers as well as professional engineers and others with a technical background.

The purpose of the meeting on Wednesday was to discuss organizing regular meetings of the Atlantic chapter of CATAIR as video conferences.  Also supplemental “get togethers” to discuss reconstruction topics and, generally, to stay in touch.  In the past we met in person in Amherst, Nova Scotia and Moncton, New Brunswick.

My interest in Zoom was tweaked.  A little more checking and I concluded video is going to play a big part in forensic engineering investigation in the future – starting with the initial briefing.


It’s big in the corporate world now.  More than half the Fortune 500 companies confer on Zoom video regularly.  Almost all the top 200 US universities do.  And that was the case before COVID-19 shut everything down.  After the lock-down is lifted many will still be working from home and conferring on video.

One of my three daughters oversees computer support for a testing laboratory with five divisions at a large hospital in Toronto.  She virtually meets with staff on video throughout the day using Zoom.  Another daughter in Edmonton works from home for a university and often relies on Zoom to connect.  My third daughter practices vet medicine in North Berwick, Maine.  Hopefully she relies on video conferencing – anything to stay clear of the COVID-19 epic centre in New York, in a sense, just down the road from her.


Connecting on video is enhancing our lives socially as well.  My neighbour connects with his two daughters out west weekly courtesy of the Zoom app.  One of the chaps who took part in Wednesday’s virtual meeting and his partner catch up with their family on video as well.  Guess who is going to be “meeting” with his daughters when he gets up to speed with Zoom?


There’s no question conferring on video using apps like Zoom is going to impact forensic engineering investigation.  For sure during COVID-19 but afterwards as well.

Forensic experts can be briefed on video now about a failure or accident so they can get on site before the dust settles and do a visual assessment.  The tools are there to be used.

This type of simple, cost effective assessment is sometimes all that is necessary.  If more forensic work is necessary, meeting during a video conference to report progress is certain to ensure continued savings.






COVID-19 and an initial forensic task a.k.a. a visual site assessment, sans social distancing

Like mine, your work has possibly slowed a little because of COVID-19.  For that matter, I’m sure most practices and vocations.

However, we can and should follow through on one forensic task: An initial visual assessment of a failure or accident site, as soon as possible after an incident.  It’s just as important during COVID-19 days and just as easy.

This is also a forensic task that quite often is all that is necessary in determining probable cause, and quite often, cost effective in the extreme.

It’s also important to be seen to have done this by the parties to a dispute or claim.  It’s easier to explain doing too much than too little.  COVID-19 would not cut it as an excuse for not getting on site as soon as possible.

COVID-19 is not a good reason because an initial visual site assessment is carried out by the forensic expert alone. Social distancing is not a problem when you’re walking around a site by yourself doing things like the following:

  1. Noting the features in the terrain, in general, or on the site, in particular, relevant to the accident or failure,
  2. Examining the exposed surfaces of the failed structure and how it was initially constructed and it’s condition now,
  3. Measuring the parts of the structure or component that failed,
  4. Examining the surface where the victim slipped and fell,
  5. Taking terrestrial and aerial photographs and video, and, generally,
  6. Getting calibrated to the site.

Neither is social distancing a problem when taking a briefing by phone, e-mail or Zoom.  Nor reviewing documents sent by courier.  Taken together, a virtual visual site assessment.


I recently looked at e-mailed photographs of the scene of a slip and fall.  The probable cause was known but not who was responsible.  I was able to identify from the photographs the three investigative tasks needed for determining responsibility.  One task was getting some accurate measurements on site – rough ones were possible from the photographs – plus getting that calibrating visit under my belt.

But, as I type this, it occurs to me that one of the other three tasks could be carried out in a very preliminary way and indicate probable responsibility.


However, we do need to get on site quickly after an incident because physical and environmental conditions change and important data can be lost.  This is the case whether it’s a breaking-news, catastrophic failure or a tiny component failure, a terrible accident or a seemingly “simple” slip and fall.  Examples of important data include:

  1. The volume of oil in the ground and the ground water after a fuel oil spill; (the change in volume depends on subsoil conditions and the topography)
  2. The location of the plume of contamination on the water table – think, a pool of oil in the shape of a feather with the big end downstream; (the location changes, sometimes very quickly, and this is important data)
  3. The condition of the floor surface at the location of a slip and fall accident; (this can change quickly)
  4. The height of flood water; (changes very quickly)
  5. Weather conditions after a crane collapses or a bridge fails; (this changes quickly but micro weather records sometimes exist)
  6. The size and configuration of cracks in a wall; (these features of a crack can change fairly quickly and often get worse)
  7. Tidal conditions at the location of a seaside structural failure; (changes cyclically)
  8. Sagging floors in a building; (are they sagging more?)
  9. Foundation conditions causing a building to vibrate; (these conditions change seasonally when they’re causing a problem)

Often, as indicated above, an initial visual assessment can point confidently at the probable cause of a failure or accident.  For example:

  1. I knew why a gabion wall failed on the coast as soon as I saw it, and it wasn’t coastal erosion (a gabion is a wire basket filled with rock)
  2. I also knew why a building vibrated in the winter as soon as I saw the sloping site and how the foundations were constructed
  3. The cause of a slip and fall accident on a wet floor in a dry sauna came to me on the drive back to my office – and where the water came from – after visually examining the site
  4. I knew why a furnace oil tank collapsed into a trench spilling oil everywhere based on a virtual visual site assessment – a study of site plans and photographs taken by others (I wasn’t permitted to go on site nor even drive the road nearby)

And if a more detailed and intrusive investigation is needed – none was in the examples above except skid-resistance testing on the slippery sauna floor – then the visual site assessment ensures more investigation is well planned.

For sure, COVID-19 might delay additional investigation till the lock-down was lifted –  but it can’t delay a visual site assessment by a lonely forensic engineering expert.  Nor a virtual visual site assessment.

(Posted by Eric E. Jorden, M.Sc., P.Eng. Consulting Professional Engineer, Forensic Engineer, Geotechnology Ltd., Halifax, Nova Scotia, Canada