I recently mentioned how you can think – hypothesize, about the cause of a failure or accident based on very little evidence, then modify your thoughts as more comes in. (Ref. 1)  This is the nature and technique of forensic engineering investigation.  Some of the evidence can be as brief as a chance remark years ago, as happened to me.  Following is another example of this process.

(Counsel benefits from a process like this – ideally when the merits of the case are assessed.  But also when you think you have enough technical evidence to go forward and want to cut costs by stopping the forensic investigation)

***

There are a lot of multistory buildings in the Halifax area.  I learned that at least one is defective because the floors are sagging – the floors are “wavey” to use one person’s description.  A defect is a failure in engineering.

The floor in one of the rooms on the 10th floor slopes down 1.5% to 2.5% from the end to the middle.  It sags in the middle.  The room is 22 feet long by 12 feet wide.  That means the floor sags 2 to 3 inches.  That’s a lot for a commercial building.  It’s far more than a construction tolerance of 1/4 inch.  You can see the slope in the length of the conference tables.  I measured the floor with a tape and a digital level.

In another large, square room chairs with casters roll to the left side of the room when you’re sitting in one.  That happened to me.  The floor slopes down to the left in this room compared to the middle in the other room.  At least on the left half of the room where I was sitting.  Quick measurements in three places in the room and also in the reception area indicated slopes of 0.1% to less than 1.0%.  Staff in the office on this floor report that the floors slope in all the rooms.

I saw that the floors were not level on the 12th floor of the building.  Office staff were not conscious of this but they did say that previous tenants reported that the floors were not level.  I also saw the floor sloping down from a concrete column in an office on the 4th floor.

A staff member familiar with four floors in the lower part of the building reported that the floors were “Wavey.  Not very, very, very level.  We have to level when we do renovations”.

Building construction

The building is made of concrete – concrete foundations, columns and floors.

The foundations are supported on bedrock which is very strong.  I learned this from a friend who saw the foundations being constructed when his company worked on the building site.  He also said multistory buildings like this are erected quickly so they can be rented as soon as possible and make money.

Construction technique

The construction technique used to erect multistory concrete buildings is sensitive to construction schedule.

A concrete floor in a multistory building is constructed by placing concrete in forms that are supported on jack posts.  The jack posts are in turn supported on a previously constructed concrete floor below.  The floor below will also be supported on jack posts below it.  Jack posts are steel posts whose length can be adjusted – jacked up

You can see this construction technique in different places in Atlantic Canada – a number of jack posts at each floor level – usually three or four levels, below the floor under construction.  There are at least two buildings under construction now in Halifax using this technique, one on Jos. Howe Drive and the other on Young Street.

The technique involves removing the jack posts from the lowest floor and leap-frogging over the upper floors to support the forms for the next floor under construction above.

Construction schedule

I knew the construction manager who directed the work crews erecting the defective building years ago.  He told me one time – the chance remark, that he was on a very tight schedule to construct the building – had to get it up in a hurry.  Just like my friend said for multistory buildings, in general, but this one sounds like it was rushed even more.

Concrete strength

The jack posts are removed from the lowest level when the strength of the concrete forming the floor being supported just above is high enough.  The strength of concrete floors is specified by the design engineer according to the planned construction and use of the building.  Concrete sets up – gains in strength, over a number of days from the wet concrete when placed in forms to the rock-hard concrete later.  The quality of the concrete delivered to a building construction site is checked by testing companies to ensure it will set up to the design strength.

Analysis of the cause of the “wavey” floors

Building components

The defective, multistory building had five components when it was under construction:

• Concrete columns
• New concrete floor
• Forms temporarily supporting the new floor
• Jack posts supporting the forms
• Recently constructed floors supporting the jack posts

Limited information

The limited information for a hypothesis in this case is:

• Floor condition: – Sloping and sagging but usable
• Building construction: – Simple concrete columns and floors
• Construction technique: – Construct a new floor by placing concrete in forms supported on jack posts resting on recently constructed floors below.
• Construction schedule: – The multistory building was put up in a hurry
• Concrete strength: – Concrete gains its full strength over time
• My experience during construction of one multistory building and examination of another during construction

Possible causes

Analysis of the limited information suggests the following possible causes associated with one or the other of the building components.  The causes are listed beginning at the top surface of the new floor:

Cause #1. The floor forms were constructed level but the concrete was not placed and troweled level by the concrete finishers

I believe the concrete was placed and troweled level – or to the level of the forms, an important qualifier.  I’ve seen concrete finishers at work often enough.  They are proud of their craft.  And besides, the concrete form they must place and trowel the concrete to is right there in front of their eyes a few feet away.  It would be difficult to make a mistake.

Cause #2. The floor forms were not level because mistakes were made in measuring the position of the new floor on the concrete columns.  These marks are the starting point for leveling the forms

Similarly, it would be difficult to make a mistake measuring the position of the new floor on the concrete columns.  This is a simple measurement with a tape.  I can imagine it being checked and rechecked.  “Measure twice, cut once” like a carpenter does.

Cause #3. The floor forms were not level, either because of the leveling method or because the posts were not jacked up properly

The jack posts would be placed according to the level of the forms and adjusted up or down a little as required by the form leveling technique.

Based on what I’ve seen on construction sites, I can easily imagine a carpenter’s level with a spirit bubble being used to check the level of the forms and the need to adjust the jack posts.  Cheap and quick on a job that’s in a hurry, also inaccurate.  Inaccurate in different directions too depending on where you put the carpenter’s level. This would result in different slopes to the floor forms – and different slopes and sags to the finished concrete floor like I saw in the defective building.

What I’ve seen – the plumb of concrete columns being set with a carpenter’s level – floor after floor after floor on one 20 story building.  Very crude.  It’s not too great a leap of faith to believe that the floor forms were set “level” in the same way in the 20 story building.

Cause #4. The forms sagged when the heavy concrete was poured because the distance between the jack posts was too great

This might be possible but unlikely because jack posts would be placed at the construction joints between concrete floor forms.  The forms themselves would be more than rigid enough to support a layer of concrete a few inches thick.  The forms are likely to be reusable – certainly from floor to floor, but also from job to job.

Cause #5. The floors sagged because the jack posts were removed before the concrete set up and was strong enough

This is possible.  I can’t dismiss it.  Particularly if low strength concrete was accepted at the construction site and there were only three floors of jack posts in place.  However, I might expect sloping and sagging to be more broadly distributed across the new floor rather than quite variable like in the defective building.

The floor in the long, narrow room on the 10th floor that tweaked my interest sagged 2 to 3 inches over about 10 feet.  And the slope was in a different direction in the square room about 25 feet away from the narrow room.

I also can’t imagine low quality concrete being accepted at a construction site – truck load after truck load and floor after floor.

But this cause is possible because I just don’t have enough information on how deflection three or four floors down would affect a new floor way up above.

Cause #6. The floors sagged because an inadequate number of the lower floors were supported with jack posts beneath the upper floor that was under construction

This cause might be possible if jack posts were placed at only two levels rather than the three or four that seem to be normal.  I see four in the two buildings I drove by recently.  It seems like a risky decision for a construction manager on a very tight schedule and in a real hurry to get the building up even if he’s prepared to accept low strength concrete.  I also don’t know as mentioned above on how deflection two or three floors down would affect a new floor.

***

What do I think is the likely cause of the “wavey”, sagging floors based on the limited evidence?

I think – my initial hypothesis, that the floors slope and sag – because the forms were not leveled properly – Cause #3 – in the rush to get the building up.

***

The following is what we do in forensic engineering when we think about the cause of a failure or personal injury for Counsel and the justice system:

• Gather the evidence as limited as that might be and from whatever source,
• Analyse it – carefully study each piece of evidence, note it’s nature and significance, how each piece relates, where each piece leads and what the whole tells us,
• Identify and list possible causes, and related technical issues
• Factor in our experience,
• Think about and hypothesize cause – come down on one cause or the other,
• Go gather more evidence
• Analyse it – etc. etc.
• Check if the initial hypothesis stands up to the new evidence,
• Accept the hypothesis, modify it, or reject it completely and start over.

More evidence in the case of the defective, multistory building would be a precise elevation survey and contouring of many or all of the floors in the building.  Basically quantify the nature and extent of the problem, the defect whose cause you must determine.  But this is not likely to happen because the building although defective is functioning quite okay.  I’m sure there are others like it in Atlantic Canada.

References

1. Bridge failure in litigation due to inadequate bracing – City of Edmonton.  But, inadequate for what?  Posted March 15, 2016

(Forensic investigations are carried out by hypothesizing the cause of a failure or accident based on the evidence available at the time – as limited as this might be, and revising the hypothesis as more evidence comes in.  This successive hypothesizing and revising might be done several times during an investigation.  The following is an example of this process.

Counsel benefits from a process like this early in a case – ideally before deciding to take the case, when an expert studies the evidence, then, based on the available evidence, identifies and evaluates the technical issues and the cost to investigate these)

***

The cross bracing was inadequate.  I concluded that last March, a few days after the failure. (Ref. 1) I used the bridge failure to illustrate how a hypothesis – an idea, could be formed about the cause of an engineering failure based on very little evidence.  In this case, all I had were some on-line photographs .

But, inadequate for what?  To resist the service plus construction loads – weights and pressures on the bridge, as required by the Canadian Highway Bridge Design Code?  If there’s no bracing at all – none, these loads would cause the girders to buckle sideways in the order of 375 mm, not the approximately 1,000 mm or more seen in the photographs.

The 1,000 mm was determined from the photographs by scaling like we do on maps.  The known 3.0 metre depth of the girders at the middle section – see Sources below, is like a scale or ruler in the photograph.  This depth is about the same as the spacing between the girders, maybe a little less.  I decided the spacing was 3.5 metres.  I saw that the girders had buckled about 1/3 of the way into the 3.5 metre spacing – 1,000 mm or more.

The 1,000 mm buckling indicates a greater load was acting on the girders than perhaps was required to be resisted by the Code.  Where did the greater load come from to cause the 1,000 mm?

The only thing attached to the girder – at the top, that can be seen in the photographs is a sling at the end of a crane’s cable.  The cable is attached to a crane’s telescopic boom.  The boom would sway and flex a little in the wind that was blowing that night which would cause the sling below to tug on the girder – a point load in engineering.  Construction cameras show the girders intact at 2:00 in the morning and buckled at 2:15.

I hypothesized last March that this repetitive tugging caused the girders to buckle like they did.

The 1,000 mm magnitude of the buckling and the fact that crane booms sway in the wind supports this idea that tugging on the girders was the source of the greater load.

It would be of interest to know if the bracing that was in place – and seen bent in the photographs, was adequate to prevent buckling, except for the 1,000 mm due to the tugging.  There are simple calculations that bridge design engineers do to determine the bracing needed to prevent buckling in the order of 375 mm.

I did think about a sudden foundation soil failure causing the crawler crane to subside and the cable to tug on the girder as a result.  I dismissed this idea because the crane had been there a while lifting 40 tonne girders into place.  Foundation failure would have occurred some time before because of these heavy lifts if the foundation soils were inadequate.

The only way I would revise my hypothesis is to note that the crane operator did not contribute to the failure because he was not working.

The initial hypothesis

The bridge failed because the middle crane’s boom moved in the wind – possibly also due to the crane operator’s actions, causing the cable to periodically tug at the middle section of beam #6 and eventually cause it to bend.  This caused the middle sections of beams #5 and #4 to bend as well because they were connected to #6 by some cross-bracing.  The cross-bracing was inadequate to resist the force from the tugging indefinitely and eventually failed too.  The middle sections of beams #3, #2, and #1 did not bend and fail because they were adequately cross-braced.

Revised hypothesis

The bridge failed because the middle crane’s boom moved in the wind causing the cable to periodically tug at the middle section of beam #6 and eventually cause it to bend.  This caused the middle sections of beams #5 and #4 to bend as well because they were connected to #6 by some cross-bracing.  The cross-bracing was inadequate to resist the force from the tugging indefinitely and eventually failed too.  The middle sections of beams #3, #2, and #1 did not bend and fail because they were adequately cross-braced.

Sources

I studied various photographs on-line including construction photographs taken at the time of the failure.

I spoke with Barry Bellcourt, the Road Design and Construction Manager for the City of Edmonton, a few weeks ago, also Bryon Nicholson, Manager of Special Projects. Barry mentioned the litigation and the city’s position.

I also learned from him that the bridge consists of seven, 40-tonne girders.  Each girder consists of two 7.5 metre long end sections and a 43 metre middle section.  The end sections are 4.5 metres deep arching up to 3.0 metres at the middle section.  The sizes are approximate.

I saw and photographed the underside of the repaired bridge girders from Groat Road in early August when I was in Edmonton.

I understand it was windy the night the girders buckled and that was the reason workers were not on the job.

I spoke with four companies in Nova Scotia that operate cranes.  I learned that crawler crane booms move in the wind; flex and sway.  There is greater movement sideways because there is less strength that way.  Telescopic booms move more than lattice booms because of the greater surface area.  Booms are lowered to the ground in strong winds.  One company doesn’t operate its cranes in winds of 50 km/hr or more.

I also talked with Amjad Memon, a structural engineer with the Nova Scotia Department of Transportation, about the Canadian Highway Bridge Design Code.

References

1. Wind, construction crane and inadequate cross-bracing caused Edmonton bridge failure: An initial hypothesis.  Posted March 27, 2015
2. Why, in a recent blog, didn’t I seem to consider foundation failure as a possible cause of the Edmonton bridge failure?  Posted April 3, 2015
3. Bridge beams that fail are sometimes like balloons filled with water – squeeze them and they pop out somewhere else.  Posted May 20, 2015
4. Google: Edmonton bridge failure, Groat Road, Buckling, etc. to see photographs of the buckled girders.

I attended the regular quarterly meeting of CATAIR last Friday – this time at Dartmouth Crossing to enable some field testing, and learned a few things, both encouraging and disturbing.

1. I felt good learning that there are training and qualifying programs in Canada for traffic accident investigators.
2. Also, not surprisingly, that school buses have numerous safety features.
3. I was disturbed learning about the blind spots at the back of a school bus where the driver can`t see.  What he sees isn’t all of what might be there.

CATAIR along with ACTAR are two separate associations of traffic accident investigators.  The one is a forum for investigators to meet and share experiences and ideas.  The other is an accrediting organization for investigators. (Ref. 1)

It`s in order to take an interest in this field of practice considering the number of traffic fatalities in Atlantic Canada in a year, not a few of which result in charges under the law, civil litigation or insurance claims.

Encouraging

I suggested last week that it is important that your traffic accident expert is well trained, experienced and accredited.  That is still true.  ACTAR can perhaps be seen to be the ultimate and most demanding accrediting group.

However, I did learn at the meeting on Friday that there are qualifying programs in Canada that are demanding enough.  They vary across the country but generally require that traffic accident reconstructionists study and train and go through several levels of qualification.

A course for police officers comprises three main levels.  Two levels are done in the area in which the applicant serves and focuses on investigation of the traffic accident.  The third is completed at a Canadian Police College and covers reconstruction of the accident.  I understand that members of the public can take this course for a fee.

It’s important that an investigator reconstruct a traffic accident generally in accordance with the procedures his peers in the area would follow, and to have comparable qualifications.  That is, to measure up to the standard of care existing in his area of Canada at the time. (Refs 2, 3) That standard is certain to include the expectation that you went through a qualifying program of some sort, in view of the fact they do exist.

If charges or a dispute arises from the traffic accident the investigative procedures followed by the investigator may be evaluated by his peers at the report writing stage or the discovery and trial stages, according to the standard of care.

***

I mentioned a few days ago that the meeting on Friday would do the following things, and these got done:

1. See a demonstration of the latest school bus safety features,
2. Perform instrumented braking and acceleration tests,
3. Measure the bus’s turning radius and rear wheel off-tracking, and,
4. Examine sight lines/views obstructions.

There are school bus safety features too numerous to mention, but the bus driver did a good job briefing us on these.  Proper thing parents would say. These features include:

• Exacting bus driver training and qualification,
• Walk around safety checks,
• Knowing where the bus is at all times,
• Training students on how to exit the bus in an emergency – including through roof escape hatches,
• Front windows that pop out in an accident,
• Doors that can be opened easily both inside and out,
• Etc.

I was impressed to learn that these very large buses when empty, at a speed of 50 km/hour can be stopped within about 2/3 to 3/4 the length of a bus when the brakes are applied.  Dr. Stu Smith, C. Tyner and Associates, measured these speeds and stopping distances with a braking test computer.  Skid resistance or sliding resistance of the asphalt pavement was also measured by consultants using a drag sled, a test that is very similar to the coefficient of friction test in high school physics.

Disturbing

What disturbed me was the school bus driver’s blind spots at the back.  I sensed from the tone of the bus driver`s voice that these are worrying.  They just can`t see everything at the back of the bus from the driver`s seat regardless the number and size of the rear view mirrors.

I think it’s also going to be interesting to see the results of the rear wheel off-tracking measurements.  The rear wheels are in a different place to the front wheels when a bus is turning.  It`s in order for the bus driver to know where they`re at, a skill acquired by the time the driver gets his licence.  Not so easy dealing with the blind spots.  The wheel tracks were accurately located by RCMP Corporal Michel Lanteigne, Tracadie, NB using total stations land surveying equipment.

***

Why should you take an interest in all of this?  How about 18 traffic fatalities on Prince Edward Island Island last year, and possibly more in Nova Scotia, New Brunswick, and Newfoundland.  And all quite likely got investigated by traffic accident reconstructionists.  Some of these I’m sure resulted in charges and possibly disputes arose and civil litigation begun.

***

Ken Zwicker, the CATAIR regional director, organized a very instructive meeting and kept it “moving right along“ during the day.  Corporal Lanteigne – who travelled the farthest, a 9.5 hour round trip, was everywhere during our field work on Friday, including on Ken`s heels.  Others came from Fredericton, I think Saint John, and from Prince Edward Island.  Several of us travelled all of 20 minutes from Halifax.

References

1. Is your traffic accident investigator well trained, experienced and “accredited”?. Posted February 23, 2016
2. Garner, Bryan A., ed., Black`s Law Dictionary, 4th ed. 2011, Thomson Reuters, St. Paul, MN
3. How the standard of care is determined when a failure or accident occurs in the built environment.  Posted June 28, 2014

There are a couple of associations that can ensure this.  I was impressed by the “science-based” nature of one.  And its support of another that has a well developed and internationally accepted accreditation program for investigators.

You might consider ensuring the expert you retain to investigate a traffic accident belongs to both groups, or your “generalist” forensic engineer retains one who does. (Ref. 1) Same as you would expect your engineering, medical, accounting, architectural, etc. expert to be registered with a recognized association.

CATAIR, the Canadian Association of Technical Accident Investigators and Reconstructionists is a support group of traffic accident investigators.  It was formed to provide a professional and affordable way of meeting and sharing experiences and ideas.

CATAIR was incorporated in B.C. in 1984 and nationally in 1991.  Ken Zwicker, Nova Scotia, current chairman for the Atlantic region, has served on the national executive since the group’s inception.  Membership consists of police officers, former officers, and consultants of various stripes from across Canada, the U.S. and overseas.

I learned about this group when I conferred with a RCMP officer in connection with a slip and fall accident that I was investigating.  He is a member of CATAIR.  Members use some techniques similar to those I do when investigating accidents.

I have a general interest in how different groups investigate technical issues in their work, and how these techniques might be adapted to forensic engineering investigation – science in general, crime, medicine, etc., and now traffic accidents.

The Atlantic region meets quarterly and I started attending as a guest.  The next meeting is this Friday in Dartmouth.  There’s often a technical session and field day during the meeting.  The association investigates test procedures and calibrates testing equipment during these sessions.  Seeing this during my visits revealed the science-based nature of the group.  Just what you want in your experts and their associations.

The meeting on Friday will:

• See a demonstration of the latest school bus safety features,
• Perform instrumented braking and acceleration tests,
• Measure the bus’s turning radius and rear wheel off-tracking, and,
• Examine sight lines/views obstructions.

The national annual general meeting was held in Dartmouth last fall.  I attended a meet-and-greet and chatted with members from across Canada and the U.S.  These are well experienced traffic accident investigators, and some have gone on to train people on how to prevent accidents.  Examinations were held during the AGM for investigators who wanted to be accredited as meeting a minimum standard.

ACTAR, the Accreditation Commission for Traffic Accident Reconstruction, an international group formed in 1991, promotes recognition of minimum standards for traffic accident reconstruction.  To that end the commission developed a multi-part accreditation examination.  It’s one of the most comprehensive examinations I’ve seen outside of a university engineering program.

Applicants must meet certain standards of education and experience.  They are then required to complete separate theoretical and practical examinations covering more than 10 topics for each.  The topics focus on the math, physics and field testing and evaluation in traffic accident investigation.  The examinations are taken in different levels and you progress through these to become accredited.

ACTAR’s examinations are so comprehensive that a mini industry has developed to prepare applicants to take the exams covering topics like the following:

• The nature of the examination
• Exam preparation
• Practice examinations
• Test examination

Accredited investigators have successfully completed the examination and are properly trained and experienced in accident reconstruction.  Status in ACTAR is maintained after completing the initial examination by obtaining a minimum number of continuing education units over a five year period.  The continuing education we must all embrace in our professions.

This is not to say that traffic accident investigators who have not done the examination are not qualified.  I know of at least two that certainly are qualified.  What it does do is demonstrate to the public and the justice system that your expert’s qualifications have been “peer reviewed”.  This might be important in some cases.

You can visit these groups at www.catair.net and www.actar.org

Reference

1. The “generalist” forensic engineer.  Posted February 5, 2016

You might be interested in CATAIR, the Canadian Association of Technical Accident Investigators and Reconstructionists.

It’s quite a mouthful but members of this national group do exactly that – figure out why and how a traffic accident happened, reconstruct it.  Not too much different than figuring out why a building, bridge or mall collapsed or a person slipped and fell.  The objectives are the same, the techniques are different.

This type of person – a reconstructionist, could show up in your civil case, engineering investigation or insurance claim’s file. One did on an engineering investigation of mine.

I attended the first session Sunday evening of CATAIR’s annual, week long AGM at the Holiday Inn, Halifax.  The meeting is held in conjunction with a five day advanced collision reconstruction course.  Getting familiar with new technology – a “silver box” in this case, to collect data on a collision from a vehicle’s black box.

An estimated 22 people will take the course.  They come from across Canada and several U.S. states.  I spoke with fellows from South Carolina, British Columbia, Alberta, Ontario and New Brunswick. Another is up from Missouri.  The course is being given by a well regarded chap from Maryland.

Similar groups exist in the U.S. but they are not national in scope – and a bit international, like CATAIR.

Many of the people taking the course are police officers or were at one time.  Some others are private consultants – engineers and technologists of various stripes. Almost all investigate and reconstruct motor vehicle collisions.  One, the chap in N.B., has gone on to educate truck fleet owners on avoiding collisions.

These people are very busy.  The officers from Alberta and Ontario reconstruct collisions full time – no foot or car patrols for them.  Not surprisingly, considering that there are approximately 3,000 motor vehicle fatalities in Canada each year and 15 times that in the U.S. Then there are the serious injury accidents that are investigated and reconstructed.

I was introduced to the group by engineering colleagues of mine, private consultants Dr. Stu Smith, Cliff Tyner and Al Tupper who reconstruct motor vehicle accidents.  Ken Zwicker, President of the Atlantic provinces chapter of CATAIR, also a private consultant and former RCMP officer, has been quite supportive of my interest in the group.

My interest in CATAIR and accident reconstruction stems from my interest in different engineering and scientific investigative procedures and techniques and their application to forensic engineering.  I was quite impressed a couple of years ago when I learned from Stu and Al of the quite rigid testing and analysing carried out in motor vehicle accident (MVA) reconstruction.

I investigated the cause of the John Morris Rankin fatal MVA a few years ago for the RCMP.  I realize now that the police at the time gave me the results of a collision reconstruction by one of their own.  Basically a description of the accident and the vehicle speed at the time.  I was asked to establish if the pile of salt on the highway contributed to the accident.

I did this with full scale field testing – similar to that done in speed bump design, using the same type of vehicle driven by Mr. Rankin, a Toyota 4-Runner.  I filmed the testing and this filming was key to demonstrating the contribution.

There are different types of accident investigation – police, insurance and workman’s compensation to name three.  The results of collision reconstruction could contribute to any one of them:  And show up in your civil litigation case or insurance claim’s file, as one did in mine.

I posted five blogs in the past three years on writing expert reports. (Refs 1 to 5)  And referenced two excellent texts. (Refs 6 and 7)  These are guidelines for experts, as well as for those of you practicing law and insurance claims management and consulting – to help you recognize well written, technical reports.  I emphasized the need for well written reports because of the intent of civil procedure rules governing experts – like Rule 55 in Nova Scotia, to expedite the settling of disputes.

However, missing from my blogs were guidelines on composing a report – selecting the words, assembling them into sentences, the sentences into paragraphs, and the paragraphs into report sections.

William K. Zinsser’s book “On Writing Well” solves that problem. (332 pages for $19.99 at Chapters) (Ref. 8)  This is one of the most informative, engaging and humorous books on writing non-fiction – e.g., expert’s reports, that I’ve seen.  And his book is well written, as you might expect, pulling you right along page after page.

Mr. Zinsser’s book has been in print for 39 years – longer than most of us have been practicing.  It was first published in 1976.  The 7th edition came out in 2006.  I learned about the book when I read his obituary in the Globe and Mail in May. (Ref. 9)  By then it was recognized as a classic, like Strunk and White’s “The Elements of Style” which it complemented. (Ref. 10)

Strunk and White’s little book noted the dos and don’ts of writing.  Zinsser’s big book applied those principles in 25 chapters to the different methods and forms of writing non-friction.  Chapter 15 on writing for Science and Technology is most relevant to expert report writing.  It is based on a simple principle: Writing is thinking on paper.  Another chapter on Clutter is also good – getting rid of jargon and useless words.

Zinsser says that in making scientific and technical material accessible to the lay person – the purpose of an expert’s report – “Nowhere else must you work so hard to write sentences that form a linear sequence (sequential writing).  This is no place for fanciful leaps (of faith) or implied truths.  Fact and deduction are the ruling family.”  Put another way, “Go from what you know to what you don’t know”. (Ref. 11)

He tells us to imagine technical writing as an upside-down pyramid.  Start at the bottom with the one narrow fact the reader must know before he can learn any more.  For example, the technical issue in a case or claim.  The second sentence broadens what was stated first, making the pyramid wider, and the third sentence broadens the second, so that you can gradually move beyond the facts into analysis, interpretation, conclusion and opinion – the reason the man slipped and fell, the cause of the bridge failure, the location of the plume of contamination, why inadequate foundations, the source of the flood water.

Does “sequential writing” resonate with expert report writing?  This phrase appears often in Zinsser’s book in chapters on all forms of non-friction writing but nowhere is it more relevant than writing for Science and Technology – expert report writing.

Civil procedure Rule 55 requires experts to state the basis of their opinions.  Writing “sequentially” – thinking on paper, ensures we do this.

I recommend that you buy this book and give it to the next expert you retain.  Those of you practicing law, and insurance claims management and consulting, will also benefit from reading it.

References

1. Civil procedure Rule 55 will improve expert’s reports and forensic engineering investigation. Posted August 21, 2012
2. Writing forensic engineering reports. Posted November 6, 2012
3. New civil procedure rule will result in the writing of better expert reports. Posted May 20, 2013
4. Thinking on “paper”, and well written, easily defended expert’s reports. Posted March 6, 2014
5. Guidelines for writing an expert witness report. Posted May 17, 2014
6. Babitsky, Esq., Steven and Mangraviti, Jr., Esq., James J., Writing and Defending Your Expert Report; the Step-by-Step Guide with Models, SEAK Inc, Falmouth, Massachusetts, 2002 
7. Mangraviti, James J., Babitsky, Steven, and Donovan, Nadine Nasser, How to Write an Expert Witness Report, SEAK, Inc., Falmouth, MA 2014
8. Zinsser, William K., On Writing Well, the classic guide to writing nonfiction, 7th ed., Harper Collins, New York 2006
9. The Globe and Mail, page S6, May 15, 2015
10. Strunk, Jr, William and White, E. B., The Elements of Style, 2nd ed., The Macmillan Company 1959
11. Maharaj, Jeremiah R., Personal communication years ago.  Jerry was a former teacher in Port of Spain, Trinidad, and my classmate at the College of Geographic Sciences, Lawrencetown, Nova Scotia.  Jerry’s comment stuck in my mind over the years as I’m sure it did for others.  It is relevant to Zinsser’s advice on writing for science and technology.

I thought to re-issue my answer to this question (see below) after reading an updated edition – 2012, of ‘Guidelines for Forensic Engineering Practice’.  The comprehensive Guidelines were originally published by the American Society of Civil Engineers (ASCE) in 2003.  ASCE saw changes in the practice of forensic engineering in the years after 2003.  These included changes in how forensic engineering should be defined. 

As stated in the Preface to the Guidelines, regarding society in general:

“Design codes and standards, construction safety regulations, tools of investigation and analysis, and dispute resolution rules and procedures have evolved since 2003, when the first edition of the Guidelines was published.

“More importantly, forensic engineering has matured, becoming a more accepted, organized, and active field of practice.”

I also thought to re-issue my answer to this question because a friend visited my blog recently and promptly left because “I don’t understand anything about that (forensic engineering)”, she said.  No surprise, really, because her profession has no need for such services.  Still, my friend’s comment made me think that I better continue to make clear what forensic engineering is about.  Lest counsel and insurance claims managers promptly leave too.  People who really need to know about forensic civil engineering.

Civil engineering, including geotechnical and structural engineering, is basically concerned with the planning, design and construction of the built environment.  For example, structures – and the components of these, also their infra-structure – like buildings, roads, bridges, dams, land drainage and earth works, water and sewage treatment, distribution and collection systems, wharves and harbour works, etc.

Sometimes these structures or their components fail.  That is, they don’t work as planned and designed, they break, or they occasionally fall down completely – catastrophically.

Civil engineers as problem solvers determine the cause of these failures, and also the cause of personal injury accidents – by carrying out a forensic civil engineering investigation.

In Eastern Canada today, following on the Guidelines:

Forensic engineering can be defined as applying engineering principles, education, and knowledge to problems – failures and accidents, where liability is most often resolved in a tribunal but may be decided in a legal forum.

We investigate and determine the cause of problems and explain technical issues to lay people.  Increasingly we advise on how to fix the problem.

The Guidelines are a good reference for counsel and insurance personnel and readily available on inter-library loan.  Actually a good read in some situations, like legal practice handbooks are a good read for experts.  Chapter headings in the 2012 edition indicate the thorough coverage of the practice of forensic engineering:

• Competencies and qualifications of forensic engineers
• The standard of care
• Investigations and reports
• Ethics
• The legal forum
• The business of forensic engineering

These topics were also covered in the 2003 edition but now upgraded.

The most significant addition to the 2012 edition of the Guidelines, a separate 23 page chapter, is “The standard of care” – best described “…as the boundary between negligent error and non-negligent error”.  I`m glad it`s there because it`s a difficult area of investigation for an expert.  Counsel would do well to read this chapter.

References

1. Lewis, Gary L., Ed., American Society of Civil Engineers (ASCE), Guidelines for Forensic Engineering Practice, 2003
2. Kardon, Joshua B., American Society of Civil Engeers (ASCE), Guidelines for Forensic Engineering Practice, 2012
3. What is forensic engineering? Posted November 20, 2012

***

What is forensic engineering? – as posted on November 20, 2012?

You’ve probably seen the word “forensic” in the newspapers often enough.  The term is applied to many scientific disciplines today and to specialties outside the engineering and scientific professions.  The following item explains what is involved in “forensic” engineering.

Origin of the word “forensic”

The word “forensic” comes from the Latin forum and as an adjective means pertaining to or used in legal proceedings.  The forensic engineer helps with the technical issues in disputes – and their resolution – arising from engineering failures.  He does this by presenting and explaining complex technical principles, technical evidence, technical facts supported by the evidence, and opinions to help the parties resolve the dispute.  More than 90% of disputes are resolved by the parties in this manner without going to trial.

Forensic engineers use engineering methods to investigate failures

In my forensic engineering practice in eastern Canada, and reviewing some literature, I’ve come to think of forensic work as the use of the engineering approach, and various engineering methods and knowledge, to investigate the cause of failures in the built and natural environments – including environmentally related failures.  A failure may mean total collapse, partial collapse or inadequate performance and serviceability problems.

The same engineering approach – the methods may change, can be used to investigate the cause of slip, trip and fall accidents, and motor vehicle and aviation accidents causing property damage, personal injury, or death.

Methods the same in forensic engineering and design engineering

The engineering approach and the methods used during forensic investigation are essentially the same as those used during design of a structure.  And in applying those methods to forensic work there would be no greater or lesser attention paid to thoroughness and accuracy.

The difference between forensic engineering and design engineering

If there is a difference, forensic work looks at what was done in the past to provide for the loads on an existing structure and whether or not it was adequate.  Design work looks at what must be done in the future to adequately provide for the loads on a proposed structure.  “Load” in engineering can be anything to do with a structure that should have been provided for or must be provided for.

Forensic engineering

“Forensic engineering” is the term now accepted to connote the full spectum of services which an engineering expert can provide.  A number of engineering disciplines might be used in the investigation of a failure.  For example, civil engineering, foundation, geotechnical, environmental, structural, chemical, mechanical, and electrical, among others.  The forensic engineer directing the investigation – usually from the discipline thought at the beginning to be most relevant to the problem, would retain other specialists as required by different facets of the problem.  I’ve done that often enough during my forensic engineering investigations.

Most forensic engineers have higher, specialist degrees in engineering and decades of experience.  They are usually retained by counsel for the plaintiff or defendant in a dispute, by claim’s managers with insurance firms, and occasionally by the court.

Anything can fail, break and fall down

Anything in the built environment can fail – buildings and their different components, including environmental components like fuel oil tanks, and civil engineering structures like bridges, roads, dams, towers, wharves, and earthworks.

Also, anything in the natural environment can fail – natural slopes, river banks, coast lines, flooding protection, subsidence protection, and erosion and sediment control.

The infra structure servicing these building and civil engineering structures can fail – infra structure like water distribution and sewage collection systems, pipe lines, power distribution systems, and tunnels.

Typical forensic engineering investigations

Forensic engineering experts might investigate why:

• a building settled,
• a building caught on fire and burned,
• a bridge collapsed,
• a dam washed out,
• oil spilled contaminating the ground,
• ice fell injuring a pedestrian,
• a worker fell off a ladder and died,
• a fatal traffic accident occurred after hitting a pile of salt on the road,
• foundation underpinning does not appear adequate,
• land or a basement flooded,
• a land slide occurred,
• etc.

The majority of failures that are investigated by forensic engineers are quite ordinary, at least in the engineering world, and are not ongoing, news-grabbing events.

Assisting the court

If the dispute can’t be resolved and it goes to trial the forensic engineer as an expert presents and explains the evidence, facts, and opinions to help the judge or jury understand the technical issues so that the verdict will be proper within the law.

In a dispute resulting in civil litigation, it is the role of the forensic engineering expert to objectively provide evidence, regardless of whether it favours the plaintiff or the defendant.

References

1. Association of Soil and Foundation Engineers (ASFE), Expert: A guide to forensic engineering and service as an expert witness, 1985
2. Cooper, Chris, Forensic Science, DK Publishing, New York, 2008
3. Suprenant, Ph.D., P.E., Bruce A., Ed., Forensic Engineering, Vol. 1, Number 1, Pergamon Press, 1987
4. American Society of Civil Engineers (ASCE), Guidelines for Failure Investigation, 1989
5. Lewis, Gary L., Ed., American Society of Civil Engineers (ASCE), Guidelines for Forensic Engineering Practice, 2003

The elephant in the room is the cost of litigation when counsel is talking with an expert.  Particularly the cost of investigating smaller cases.  Counsel doesn’t always talk with an expert about cost when the merit of a case is being assessed.  This sometimes causes problems later and may also compromise an expert’s independence and objectivity.

Small to medium size cases are the norm, not large, well funded cases brought by affluent litigants. (Refs 1 to 4)

The ‘Principles Governing Communications with Testifying Experts’, as developed by The Advocates’ Society, Ontario is a good document and was long overdue. (Ref. 3)  But there is a need for an additional principle governing communications about the cost of litigation.

There are good reasons for developing such a principle like there were good reasons for developing the existing Principles.  I understand the Principles were developed because counsel’s involvement in the expert’s report sometimes compromised the expert’s independence and objectivity.  I believe talking about the cost of litigation – after the action has begun – could also compromise the expert’s independence and objectivity, at least the perception.  My belief is based on civil, geotechnical and forensic engineering practice in Eastern Canada since the late 1980s. (Ref. 5)

Senior experts could help develop such a principle.  They could also offer comment on updating the Principles.  Good communication is a two-way process.

Often enough experts are retained months or years after counsel takes a case. (Ref. 1) And after counsel has estimated the cost of the expert`s work.  Then the expert`s invoices start coming in as he investigates the problem and these sometimes exceed counsel`s estimate.  Counsel stops the forensic investigation.  Sometimes so completely that not even an oral report of the expert`s findings go to counsel.  Findings that might point the way to justice being done – denying the court and the litigant information is touched on in the Principles. (Refs 3 and 4)

During this un-raveling process it’s not difficult to imagine a real or perceived compromising of the expert’s independence and objectivity.  These qualities are related to the reliability of an expert’s investigation and opinion.  Reliability is related to the thoroughness of an expert’s work, the gathering of sufficient data.  Thorough work can be expensive.  And when this thorough work is stopped before completion, sometimes this compromises the expert`s independence and objectivity.

A summary of facts supporting the need for a principle governing communications about the cost of litigation:

• The Principles, and the associated Position Paper, already note that litigation is expensive and that there are affluent and less affluent litigants.
• The smallness of some cases – the norm, really, which feel the presence of the elephant, is also mentioned in the Principles.
• Experts are not always consulted when the merits of a case are being assessed.
• Counsel is usually not qualified to estimate an expert’s costs.
• Nor to recognize when it’s difficult or impossible to estimate the cost of an expert’s investigation, analysis and reporting. (Ref. 6)
• The present situation could compromise an expert’s independence and objectivity.

These facts – and I’m sure there are others, support the need for a principle governing counsel’s communications with experts about the cost of litigation.

References

1. Forensic engineering practice in Eastern Canada (and supporting references), posted May 7, 2015 http://www.ericjorden.com/blog/2015/05/07/forensic-engineering-practice-in-eastern-canada/
2. What do forensic engineers investigate in Atlantic Canada (and supporting references), posted October 9, 2014 http://www.ericjorden.com/blog/2014/10/09/what-do-forensic-engineers-investigate-in-atlantic-canada/
3. Principles governing communicating with testifying experts; their development and acceptance, posted June 25, 2015 http://www.ericjorden.com/blog/2015/06/25/principles-governing-communicating-with-testifying-experts-their-development-and-acceptance/
4. The Advocates Society, Position paper and principles governing communications with testifying experts, published June, 2014 Ontario  http://www.advocates.ca/assets/files/pdf/news/The%20Advocates%20Society%   20%20Position%20Paper%20on%20Communications%20with%20Testifying%   20Experts.pdf
5. www.ericjorden.com and www.ericjorden.com/blog
6. A bundle of blogs: A civil litigation resource list on how to use forensic engineering expertsh http://www.ericjorden.com/blog/2013/11/20/a-bundle-of-blogs-a-civil-litigation-resource-list-on-how-to-use-forensic-engineering-experts/

You might be interested in the list below of the stages in the “life” of a structure in the built environment.  Structures include earthworks and waterworks – a reshaping of the natural environment, as well as buildings and bridges.

I came across the basic list – the first nine stages, while reading the latest, 2012 edition of Guidelines for Forensic Engineering Practice. (Ref. 1)  I added the 10th stage – demolishing, because that’s what often happens to structures after they have been decommissioned.  The list is a useful breakdown of the aging of a structure.

The Guidelines were published by the American Society of Civil Engineers (ASCE).  Civil engineering includes structural engineering and geotechnical engineering.

I see the list providing context and facilitating communication between counsel, insurance claims managers and consultants, and an engineering expert.  Failures and personal injury accidents can occur pretty well any time during the life of a structure.

Principles governing communication between counsel and expert have been developed recently by The Ontario Advocates’ Society. (Ref. 2)  The following list of stages in the life of a structure will further help counsel and an engineering expert talk to one another when a failure or personal injury accident occurs:

1. Conceptualizing
2. Planning
3. Designing
4. Constructing
5. Operating
6. Maintaining
7. Renovating
8. Reconfiguring
9. Decommissioning
10. Demolishing

ASCE say that, “Failure can be defined as an unacceptable difference between an actual condition or performance and the intended or reasonably anticipated condition or performance.”  This can occur during any stage in the life of a structure.

Furthermore, “Failure need not involve a complete or even partial collapse.  It may involve a less catastrophic deficiency or performance problem, such as unacceptable deformation, cracking, water- or weather-resistance, or other such phenomena.”

It’s not difficult to imagine that failure can occur at any stage.  Nor that personal injury accidents can occur at any stage.

Communication is easier for both counsel and client and counsel and engineering expert if we all have an idea of a structure’s “life” and the stages it goes through as it ages  The list above can help us.

References

1. Kardon, Joshua B., ed., Guidelines for Forensic Engineering Practice, American Society of Civil Engineers (ASCE) 2012
2. The Ontario Advocates’ Society, Principles Governing Communications With Testifying Experts June 2014 Toronto

The Principles developed by The Advocates’ Society, Ontario and published June, 2014 have been well received by the judicial system.  And in a short time too.  I reported on these June 11. (Refs 1, 2)  I was pleased with them as a civil engineer retained as an expert often enough.

Following is more information on the development and acceptance of the Principles.

I enquired but wasn’t able to learn how they have been received in Eastern Canada.  I can`t help but think that once they are known to the barristers’ societies in this area they will be quickly accepted here as well.

I later e-mailed Dave Mollica, B.B.A., LL.B. about the Principles.  He is Director of Policy and Practice for the Society.  Dave said, “…the Principles were released only a year ago, but we have received very positive feedback“.  Following is a summary of his remarks: (Ref. 3)

“The Principles were developed following a case from the Ontario Superior Court of Justice (Moore v. Getahun) when the judge suggested that it was inappropriate for counsel to review drafts of expert reports with an expert prior to the filing of the report.

“A Task Force of around 20 members of The Advocates’ Society, all litigators in various areas of practice, was struck to discuss and examine the issue.  Research into the development of expert evidence and the current state of affairs in this regard was conducted.  Task Force members shared their own practices on how they interact with experts during the litigation process.  This led to the drafting of the Principles and the accompanying Position Paper on Communications with Testifying Experts.  Earlier drafts of the Principles were shared with various parties – mainly lawyers who work closely with experts as opposed to experts directly, but I recall we did also consult with the Canadian Institute of Chartered Business Valuators.” (Dave Mollica)

Three significant developments in a year:

• The Court of Appeal for Ontario endorsed the Principles and appended them to its reasons in the appeal of the Moore v. Getahun case.
• The Advocates’ Society have incorporated the Principles into the curriculum of it’s relevant educational programming.
• The Society has received feedback that law firms in Ontario have incorporated the substance of the Principles into their expert retainer letters (sometimes appending the Principles themselves to the letters).

As a civil engineer, I’m enthused about these Principles.  They define my role when I`m serving the justice system and the parties to a dispute.

References

1. Principles governing communicating with testifying experts, posted June 11, 2015 http://www.ericjorden.com/blog/2015/06/11/principles-governing-communicating-with-testifying-experts-the-advocates-society-ontario-june-2014/
2. The Advocates` Society, Toronto, Ontario, Principles governing communicating with testifying experts June, 2014 www.advocates.ca http://www.advocates.ca/assets/files/pdf/news/The%20Advocates%20Society%20%20Principles%20Governing%20Communications%20with%20Testifying%20Experts.pdf
3. Personal communication (E-mail), Mollica, David, B.B.A., LL.B., Director of Policy and Practice, The Advocates’ Society, 2700 – 250 Yonge Street, P.O. Box 55, Toronto, ON, Canada  M5B 2L7 www.advocates.ca Tel: 416-597-0243 x.125 Fax: 416-597-1588 E-mail: david@advocates.ca