The following describes the different fees – the hourly billing rates, charged by professional engineers for consulting services in Nova Scotia.  It’s important for you to know about these because many forensic experts are professional engineers. Time/fee based billing is also the best way of overcoming the uncertainties in forensic investigation without jeopardizing the quality of the investigation.  It’s also the best way of monitoring the cost of civil litigation.

Consulting fees reviewed bi-annually by CENS

I thought of sharing this with you after attending the annual general meeting (AGM) of the Consulting Engineers of Nova Scotia (CENS) last month.  I’m a past president of the Society.  CENS is a registered Society representing the majority of consulting engineers in Nova Scotia.  It’s a member-organization of a Canada-wide association of consulting engineering firms.  There are 62 firms registered with CENS this year, and another firm has just applied for membership.

CENS reviews billing rates bi-annually and suggests average rates like those below   that are representative of those charged by members for different levels of responsibility. (Ref. 1)

Time/Fee-based forensic investigations ensure quality

Time-based methods of billing overcome the many uncertainties that exist at the start of an engineering project – and often as a project progresses, particularly if construction is involved.  A forensic engineering investigation of the cause of a failure or a personal injury accident is an engineering project with a lot of uncertainties.  Not least are unknown follow-up investigations.

I surveyed consulting engineering fees a few years ago and found similar rates elsewhere in Canada and the New England states to those charged in Nova Scotia at the time.  I suspect you would find similar rates elsewhere in Atlantic Canada today.

Principals, specialists and senior engineers rendering individual services on assignments for which they are particularly well qualified could be billed at higher rates than those shown (about 25% higher in New England).  Such assignments include forensic engineering investigation and providing expert testimony (Refs 1, 2)

Often enough, justice can’t be served until the technical issues are resolved, nor a party’s case argued effectively.  A case often hinges on the outcome of the forensic investigation – argument enough for retaining an expert early.  It’s critical that it’s well done by an experienced engineer.  The fees are understandably higher as a result considering the responsibility borne by the engineer.

Monitoring costs

When a forensic investigation is initiated on a time and expense basis, it’s important that Counsel or the claims consultant monitor costs closely without jeopardizing the quality of the services.

This can be done – monitor costs and maintain quality at the same time – by understanding the stages involved in an investigation and the roles an expert can take. (Ref. 3)  You can do this in less affluent cases – the norm in Atlantic Canada, as well as in the more affluent. (Ref. 4)

It helps to recognize that the great majority of cases don’t go to trial – I understand more than 95% – they stop at the expert report stage, or a little before the written report.

It’s also important to understand that the cost of some of the many stages of a forensic investigation are difficult if not impossible to estimate. (Refs 5, 6 and 7)  Then there are sometimes completely unknown follow-up investigations.  In situations like this it’s important to monitor costs at each stage.  There’s project management and cost control literature out there to help you do this. (Ref. 8)

Also remember that you can retain an expert in at least eight (8) different ways.  From a quite low, easily monitored total fee to something more. (Ref. 9)

Suggested hourly rates

(In the following, Leadership/Supervision is short for Leadership Authority and/or Supervision Exercised)

1. Engineer in Training……..$90/hr  Experience: 0 to 4 years.  Few technical decisions called for and these will be of a routine nature with ample precedent or clearly defined procedures guidance. Leadership/Supervision:  May assign and check work of technicians and helpers.

2. Junior Engineer………….$100/hr  Experience: 4 to 7 years. Decisions made are normally within established guidelines.  Leadership/Supervision:  May give technical guidance to junior engineers or technicians assigned to work on a common project.

3. Intermediate Engineer…$115/hr  Experience: 7 to 10 years.  Makes independent studies, analyses, interpretations and conclusions.  Difficult, complex or unusual matters or decisions are usually referred to more senior authority.  Leadership/Supervision:  May give technical guidance to engineers of less standing or technicians assigned to work on a common project.  Supervision over other engineers not usually a regular or continuing responsibility.

4. Senior Engineer………….$145/hr  Experience: 10+  Recommendations reviewed for soundness of judgement but usually accepted as technically accurate or feasible.  Leadership/Supervision:  Assigns and outlines work; advises on technical problems; reviews work for technical accuracy, and adequacy.  Supervision may call for recommendations concerning selection, training and discipline of staff.    

5. Specialist Engineer…….$170/hr  Experience: >15 years.  Makes responsible decisions not usually subject to technical review.  Takes courses of action necessary to expedite the successful accomplishment of assigned projects.  Leadership/Supervision:  Outlines more difficult problems and methods of approach.  Coordinates work programs and directs use of equipment and material.  Generally makes recommendations as to the selection, training, discipline and remuneration of staff.

6. Principal Engineer………$190/hr +  Experience: No limit.  Makes responsible decisions on all matters, including the establishment of policies subject only to overall company policy and financial controls.  Leadership/Supervision:  Reviews and evaluates technical work, selects, schedules and coordinates to attain program objectives; and/or as an administrator makes decisions concerning selection, training, rating, discipline and remuneration of staff.    

***

It’s important for you to know about these suggested fees – a good average of all firms in Nova Scotia.  And to know they’re very close to those charged else where in Atlantic Canada and not far off those charged in New England.  You can then focus on retaining an expert early in a case, monitoring costs closely and not being surprised.

This is important considering the uncertainties inherent in forensic investigation, the difficulty estimating costs, the less affluent nature of many of the cases in Atlantic Canada, and the fact that even the less affluent cases require the same thorough, objective investigation.  It’s important to ensuring the quality of the forensic investigation is not jeopardized.             

References

1. Consulting Engineers of Nova Scotia (CENS), Directory 2015/2016, Halifax, NS
2. Babitsky, MBA, Alex, Babitsky, JD, Steven, and Mangraviti, Jr., JD, National Guide to Expert Witness Fees and Billing Procedures, SEAK, Inc, Falmouth, Mass.
3. Steps in the forensic engineering investigative process.  Posted July 15, 2013.
4. The Advocates Society, Ontario
5. Difficulty estimating the cost of forensic engineering investigation.  Posted July 23, 2012.
6. Why the difficulty estimating the cost of forensic engineering investigation?   Posted September 1, 2012.
7. A bundle of blogs: A civil litigation resource list on how to use forensic engineering experts.  Posted November 20, 2013.
8. Project Management Institute, A Guide to the Project Management Body of Knowledge, Newton Square, Pennsylvania, USA (One of many good references on project management and cost control)
9. Peer review costs can be controlled.  Posted January 22, 2016.

I’ve blogged in the past about the importance of measuring in forensic engineering investigation.  About getting on site and getting your hands dirty and mud on your boots. This is particularly true when an engineering failure or a personal injury accident involves the natural environment or the foundations, soils and water beneath the site – wet, messy, untidy places.

Everyone should do this – experts, civil litigation lawyers and claims consultants alike.  Go and see and measure things.

I was reminded of this on Monday when I attended a workshop on Advanced Collision Reconstruction in Moncton – read on, your eyes won’t glaze over at what I tell you, and you may gain some insight into what’s important to experts.

The workshop was organized by the Canadian Association of Technical Accident Investigators and Reconstructionists (CATAIR) and presented by Advantage Forensics Inc, Toronto.  The course instructor was Jason Young, B.E.Sc., M.A.Sc., P.Eng., a senior collision reconstructionist with Advantage.  There was some emphasis in the course on simple measurement with tapes and rulers.  Also considerable emphasis on the analytical technique used by Jason.

Police officers – present and former, professional engineers and others attended the workshop, people who reconstruct accidents.  There’s a lot of very impressive expertise in this field in Atlantic Canada.  We do have a lot of car accidents in the area.  Also people like me attended who practice forensic engineering investigation.  I have a good interest in the techniques used in fields of investigation related to my own.

The session topics were:

1. Crush Energy Analysis
2. Introduction to Collision Biomechanics
3. Rollover Investigations

The topics might look heavy to non-technical people but they rely on simple measurements – first and foremost – and an analytical procedure and software.

We’ve all seen those pictures of horrible car crashes.  Cars and trucks so mangled in some that you are hard pressed to see a vehicle in the mass of metal.  In illustrating his lectures, Jason showed us a lot of pictures like this, also video of simulated field trials and tests.  Head-on crashes, T-Bones, rear end crashes, roll-overs, and pole and tree impacts.

The speed of the cars and trucks in an accident is key information in learning why and how the accident happened – reconstructing it.  No surprise there.  Speed is obtained from analytical procedures – Jason briefed us on one he uses, and software that are fed a lot of simple measurements.  But important measurements because garbage in garbage out.

Two basic measurements are a site survey – like in land surveying of old, and the crush depth.

The crush depth is a simple measure of the length and depth of the hole in the front, side or rear of a vehicle hit by another during an accident.  These measurements give the “damage profile” in accident reconstruction.  It’s not much different than measuring the length and depth of a trench excavated in your garden by a backhoe or yourself.   

The site survey is just that – measuring and describing the location and height of the features that characterize the surface of the site.  These would be the natural features in the terrain, the layout of the road, the position of the vehicles, the location of poles or trees that were hit, and the location of marks left on the ground by the crashing vehicles.  We do this simple kind of survey of a house lot before we build on it.

***

Two measurements – crush depth and site survey, that quantify the mess of a car or truck accident.  There’s more involved, of course – analytical procedures and software, also knowledgeable reconstructionists, but nothing happens until the measurements are taken.

I was delighted recently when I saw the text Performance Guidelines for Basements while looking for another book in my library.  The guidelines are lengthy and comprehensive like many for the built environment – 185 large-format pages.  To some, that would be a lot of guideline for what would seem to be a lowly part of a structure.

• Performance guidelines for basements by the National Research Council (NRC)

This type of easily read guideline is important to non-technical people concerned about failures and accidents in the built environment.

The guidelines were prepared for all parties involved in the planning, design, construction and maintenance of basements.  Pretty well everybody from the pick and shovel guy to the cost control people.  NRC – and similar organizations in the U.S., publish a lot of material on buildings.

Basements – and the foundations down there, are not a glamourous part of a structure.  Except, they just happen to be the sole support of the building above – the most frequently erected structure in the world.  And the basement is often the most complicated to design and construct – if you’re going to get it right.

Other Guidelines

I have other guidelines on different aspects of the built environment.  For example,

• Moisture in Atlantic Housing by the Canada Mortgage and Housing Corporation (CMHC)
• National Building Code of Canada (NBC); a set of guidelines on minimum standards
• Slip, Trip and Fall Prevention, a Practical Handbook by Steven di Pilla.  This text is good on performance guidelines for floors and stairs

I also have guidelines on investigating engineering failures and accidents when good design and construction practices are not followed.  For example:

• Guidelines for Failure Investigation by the American Society of Civil Engineers (ASCE)
• Guide to the Investigation of Structural Failures by ASCE

There are guidelines of sorts in the published surveys of how structures fail.  Knowing how things break, fall down or don’t work properly is a first step to ensuring your structure performs properly.  For example,

• Failure Mechanisms in Building Construction by David Nicastroon.  This text  catalogues and categorizes 209 different ways a building can fail.  It’s very good and readily available.  (Just think, the building you’re in now can fail in these many different ways)
• Also, the ASCE guidelines above contain lengthy sections on some of the primary modes of geotechnical, foundation and structural failure

Errors and Omissions in Guidelines

You might wonder, why bother with a forensic engineer when there are such comprehensive guidelines on getting the built environment right?  A fair question if you didn’t know that the guidelines sometimes contain errors and omissions.

For example, the NRC guidelines mentioned above illustrate an error on page 30 in construction of the footing drainage system.  There’s also an omission in these guidelines – an explanation of the need for a drainage system beneath a basement floor.

I’ve seen errors and omissions in CMHC guidelines.

There’s an omission in the NBC – as I suspect there are in some similar Codes in North America, in the vague guidance on the skid resistance of floors.  (This was the case prior to 2015)  Building inspectors make a call now on this problem but this is not good enough.  I had to get guidance from the English translation of comprehensive German research on a slip and fall case a while ago.  I did this to corroborate information I was getting from literature in the U.S. on practice in some areas there, but not in all areas and not codified.

(The NBC code is periodically updated as it was recently in 2015.  This updating is the case for many performance guidelines)

Also referenced above, the published survey of the 209 ways a building can fail is extremely good but it’s completely silent on foundation and basement failure.  And there are many ways a basement can fail as evident in the 185 pages of the NRC publication.  Quite an omission in the text on buildings.

***

Performance guidelines are good – no one would do a forensic investigation without considering the guidelines pertinent to the failed structure or component.  But not good enough to omit consultation with a forensic engineer at some point during an investigation.  They are a guide only to what must be done and achieved – and some guidelines do contain errors and omissions.

And how the expert can be trained to serve the justice system during cross-examination.  There`s a wealth of information to guide us including books and DVDs prepared by experienced trial lawyers.  Training the cross-examining lawyer must include enlightening him or her about how the expert is trained.

I thought of this when I reviewed the topics for the plaintiff legal practice conference entitled “The Doctor Is In: Medical Elements of Injury Cases”.  It’s planned for June 17th and 18th in St. John’s by the Atlantic Provinces Trial Lawyers Association (APTLA).

The last topic in the two day conference is “Making the Most of Cross-Examining Medical Witnesses”.  The conference organizers beseech lawyers to “Have no fear!.  Veteran Wisconsin trial lawyer, Paul Scoptur, will give you the remedy for curing many of the common mistakes we make when confronting the defence medical expert at trial.”

In helping you correct these mistakes, I’m certain Mr. Scoptur will tell you about the excellent resources available in the U.S. for all experts, not just medical.  Texts, DVDs and training like the following – produced by experienced trial lawyers for experts:

• Cross-examination: The Comprehensive Guide for Experts (a text)
• How to Become a Dangerous Expert Witness: Advanced Techniques and Strategies (text)  (I think the tone of this text is at odds with our attitude here in Atlantic Canada but it does contain some tips on how we can serve the justice system better)
• Cross-Examination: How to be an Effective and Ethical Witness (a DVD)
• The Biggest Mistakes Expert Witnesses Make and How to Avoid Them (text)
• Preparation and Training for Testifying (a consulting service)

(There is a bias in some of this material to the medical expert)

I have some of this material in my library – and a good amount on writing expert reports, and it’s all good.  I’ve also attended some of the conferences and workshops in the U.S..  The products are very detailed and based on study of many 100s of legal cases, if not 1,000s.

Reviewing material like this will help you get a feel for how experts can be trained and further help you correct your cross-examining mistakes.  Reviewing legal practice handbooks helps me practice as an expert.  I’m certain reviewing expert practice material will help you cross-examine us.

Why am I telling you this?  Because cross-examining lawyer and expert alike are contributing to the same thing: Justice for the injured party whether the victim of an accident or the owner of damaged property.  Albeit in somewhat different ways.  To this end, it behooves us to understand each other’s role and how we are trained for this.

.

Experts need to understand the law of expert evidence, including the latest developments.  We inform the justice system.  It’s a good idea to know the rules governing the system.  We can get a lot of what we need to know in Canada from standard text books and Google – I just checked and it’s there – except possibly the latest developments.

I thought of this when I reviewed the topics for the plaintiff legal practice conference entitled “The Doctor Is In: Medical Elements of Injury Cases”.  It’s planned for this June in St. John’s by the Atlantic Provinces Trial Lawyers Association (APTLA).

The first topic in the two day conference is “Waiting Room Reading: Case Law Updates – Expert Witnesses“.  The topic promises to report “the latest developments in the law of expert evidence from Atlantic Canada and beyond”.  And to “identify, summarize and deliver everything you need to know to keep up to date in this fast paced area”.  Including case summaries.

All experts – not just medical, would like to know about these latest developments and would benefit from the knowledge.  The conference organizers must give serious consideration to making this information available to us when the conference is over.

We are reminded often enough that as experts we serve the justice system and are to objectively inform and explain the technical issues to the judge and jury.  We can’t do this effectively unless we know the law of expert evidence – and the latest updates – and have this explained to us in layman’s language.

For example, some of us were fortunate enough to learn about Rule 55 in Nova Scotia, but not all know of it.  A very valuable rule that emphasizes objective and thorough investigation and analysis, and good report writing.  I learned about it from my client after I had carried out a complex investigation but fortunately before I wrote the report.  All turned out well.

Forensic photography documents the physical appearance of a scene soon after a crime, accident or failure occurs then presents this information to the justice system, and does this objectively. (Ref. 1)  These are the main goals.

The forensic engineer also uses the photographs to study the scene again later in his role explaining the technical issues and the cause of the incident to the justice system.  Others also learn about the scene from the photographs.  It is an exacting speciality like all the technologies involved in forensic work.

Police crime scene identification unit

I was reminded of this when I toured the Halifax Regional Police Crime Scene Identification Unit recently.  David Webber, the forensic photographer with the unit, showed me around.  I had met David earlier at a social function hosted by the police department for the Victim Services Unit.

There are 13 people in the identification unit specializing in a number of technologies.  “Lifting” and analysing finger prints from surfaces and trace fluids from clothing are two the public is familiar with.  David does the photography.  We had a difficult time getting together because he was being called out to one murder scene after another over a period of a week or more.

I didn’t get out to a crime scene but did see how David presents his photographs in a book for use by the justice system.  There is nothing in his presentation or the captions – just a single number, to sway what the justice system and others might see in the photographs.

In civil litigation, the photographs could be of a scene where a personal injury accident or an engineering failure occurred, or where an incident was re-enacted by a forensic engineer.

Almost all photographs are taken at or near ground level – what we call terrestrial photographs in engineering.  But you are certain in future to see low level, oblique aerial photographs taken with cameras fitted to drones.  I use this technique now.  The police Identification Unit are looking at using it.

Uses of photographs in court

Photographs can be used in court for illustrative purposes, if admitted by the judge, to: (Refs 1, 2)

1. Support, corroborate and explain the evidence of witnesses,
2. Supply relevant detail in the appearance of objects described in oral testimony,
3. Reveal steps taken by witnesses to arrive at their opinions, and,
4. Affect the credibility attached to a witness’ testimony. (Ref. 3)

A witness uses photographs to illustrate what was seen and done during the forensic investigation and the evidence that was collected.

A photograph can also be used as a silent witness, if admitted, as,

1. Substantive visual evidence.  The photograph is allowed to “speak for itself”.

There is no witness, the photograph stands alone, a silent witness.

Allowing photographs into court

A judge will allow photographs to be tendered as exhibits and admitted as evidence in a Canadian court if the following test is met: (Ref. 4)

1. Photographs must be relevant, that is, material to an issue at trial,
2. Also, accurate in truly representing the facts,
3. Fair and absent of any intention to mislead,
4. Verifiable on oath by a person capable to do so,
5. And if their probative value exceeds their prejudicial effect.

Put another, less comprehensive way, photographs for the court must be: (Ref. 1)

• True and accurate representation of the subject
• Free of distortion
• In proper perspective

Forensic photography as high technology

Getting a true, accurate, distortion-free perspective of the scene is where photographers like David Webber and their knowledge, skill and objectivity come in.  It’s high technology when you realize how many decisions must be made for every click of the shutter: (Refs 1, 5, 6)

1. Angle to shoot from,
2. Closeness to the subject – distant, medium distant, close up, detail,
3. Lighting – natural or artificial,
4. Film speed,
5. Lens – normal, wide, telescopic,
6. Aperture,
7. Shutter speed.

Then another series of decisions must be made when presenting the photographs objectively to the courts.

That’s forensic photography in a nutshell.

References

1. Tupper, Allison D., Use of Photographs at Trial, Chap. 15 in The Expert: A Practitioner’s Guide, Vol. 1, Matthews, Kenneth M., Pink, Joel E., Tupper, Allison D. and Wells, Alvin E., Carswell Publishing 1995
2. Goldstein, BA, LL.B, Elliot, Visual Evidence, A Practitioner’s Manual, Chap. 2, Carswell, 1991 as referenced in Matthews, Kenneth M. et al
3. Scott, J. D., Motion Picture and Videotape Evidence (November 8, 1974), Ontario Crown Attorneys Bulletin and Benson and Hedges (Can) Inc. v. Ross (1986), 58 NFLD. and P.E.I.R. 38 (P.E.I.S.C.) as referenced in Matthews, Kenneth M. et al
4. R. v. Creemer (1967), (1968) C.C.C. 14 (N.S.C.A.).
5. Wikipedia, May  8, 2016
6. Kook, Frank, photographer, Halifax, May 10, 2016

It’s better still when you watch the forensic engineer do some of his work.  We learn by seeing and doing – something like 80% to 85% of what we know is got visually.  At the very least, you will better understand your expert’s explanation of the cause of the accident or failure.

I was reminded of this recently when a client indicated that he got a lot sitting and watching me work.  I think he was quite taken by what he saw and I was impressed that he wanted to go to the scene with me.  He resolved his case based in part on what he experienced that day and the pictures he took.  I wasn’t required to give even a verbal report let alone a written report.

I was also reminded of the benefit of a site visit when I met and spoke with a forensic photographer recently – photographs, the next best thing to being there, and also good for refreshing your memory of a site visit – and when I read a short manual on forensic photography. (Ref. I)

Counsel, we don’t see you at the scene very often.  I can think of only four times in recent years.  Engineers swear by the worth of a visual assessment of a site. (Refs 2 to 6)  You are also certain to get a lot from going to the scene.

What does Counsel see when s/he goes on site?  Aside from picking up a valuable concrete impression of the scene of the accident or failure?

1. Slip and Fall Accident  Counsel and the injured party sat and watched me use non-textbook methods to investigate the cause of a slip and fall accident.  I tested the skid resistance of the floor using pork belly – a pig’s belly skin, to simulate the injured party’s bare feet.  This was recommended by medical doctors and veterinarians.

There was also a question about the source of water on a floor that was supposed to be dry.  I thought earlier about a shower in a dressing room but it was some distance away.  Still, maybe.  So I put my bathing suit on that I had with me, took a shower and walked to the area of the fall – dripping water along the way and on the “dry” area.

My client got an eye-full during his site visit.

2. Inadequate Underpinning  A young lawyer watched me excavate and expose the underpinning of a building using a backhoe and manual labour – me doing the manual work, during three days of investigative site work.  She also watched me examine the underpinning closely, and measure and photograph it.  Real dirty hands and muddy boot work.

I tried to get her down into the muddy excavation to see up close one of the worst deficiencies of the inadequate underpinning but that was too much for her.  Still she saw it from the edge of the excavation and reported back to her manager.  I’m certain she will remember that site experience and be guided by it if she practices civil litigation.

Her manager was to be commended sending her to the site.  It would have been much better if he had got out there – the one arguing the case, but at least someone did.

3. Foundation Failure  The owner’s lawyer held meetings in an industrial building that was supported on foundations that were still settling and damaging the building 10 years after construction.  He saw the building and the cracks in the walls up close.  He got visual impressions that helped him understand the report I wrote on the extent and cause of problem.

Unfortunately he was not there when I strengthened the foundation soils by grouting – a ground improvement technique not often seen in Atlantic Canada.

4.  Flooding  Counsel came to the site and saw the flooded land and the unusual source of some of the flood water.  I later took low level, oblique aerial photographs with a camera mounted on a drone – the first time I used this technique, and gave them to the lawyer to refresh his memory of what he saw when he was on site.  He didn’t say but I know it benefited him.  Hard not to.

***

I’m certain the lawyers in these cases understood my explanation of the technical issues much better after being on site, and also argued their cases more effectively.

It’s not a substitute for Counsel visiting the scene of an accident or failure but low level aerial photographs are making the expert’s job of informing the justice system much easier.  They’re that good.

They could also entice Counsel to go to the scene more often, see for himself and get a little mud on his boots if not dirt on his hands.  The young lawyer above – standing at the edge of the excavation, got the former but not the latter.  Nevertheless, she benefited just being there.

References

1. Matthews, Kenneth M., Pink, Joel E., Tupper, Allison D., and Wells, Alvin E., The Expert, a Practitioner’s Guide, Chapter 15 (by Tupper, Allison D) Use of Forensic Photographs at Trial and Chapter 15A Use of Photographs and Photographic Interpretation, an example – R. v. McGillivray Carswell Publishing 1995
2. “Technical” visual site assessments: Valuable, low cost, forensic engineering method.  Posted September 4, 2012
3. An expert’s “dirty hands and muddy boots”.  Posted December 20, 2013
4. The messiness of some forensic engineering and insurance investigations is illustrated by messy snow banks.   Posted April 14, 2015
5. More about messy, lumpy Mother Nature and how we deal with her effect on our forensic engineering and insurance investigations.  Posted April 23, 2015
6. The justice system and messy construction sites – Seeing is believing.  Posted December 17, 2015

A plaintiff’s lawyer doesn’t have a reliable legal claim – and money well spent on a medical expert, until the technical issues in a personal injury case are identified and investigated, and the cause of the accident established.  Only then can the responsible parties be reliably identified by the lawyer.

I know this because I have been retained as an expert to investigate the cause of accidents like slip and fall, motor vehicle, toxic fume emission and ladder falls.  There are different elements in cases like these.  Legal and medical elements are two.  The technical element is another – an important one that comes first in a personal injury case if it’s to start off on the right foot.

There are also several different involved parties depending on the technical cause of the accident – at least four in a slip and fall accident. (Refs 1, 2)  And a similar number in a ladder accident.

I was reminded of this when I read about the plaintiff legal practice conference entitled “The Doctor Is In: Medical Elements of Injury Cases”.  It’s planned for this June in St. John’s by the Atlantic Provinces Trial Lawyers Association (APTLA).

The two day conference looks extremely good for practicing lawyers with at least a dozen featured topics and national and international speakers from the medical and legal professions. The topics are medical or closely related as would be expected.  The topics on the law of expert evidence and preparing to discover an expert are also timely, particularly to those of us retained as experts.

An important two-part topic is on causation:

1. A pathologist’s view of medical causation in bodily injury
2. Legal causation, the law and variance from medical causation

This topic really needs to be treated in three parts for an even more complete and comprehensive conference:

1. A pathologist’s view of medical causation in bodily injury
2. Legal causation, the law and variance from medical causation
3. A forensic engineer’s view of technical causation in bodily injury and how it varies from legal causation

How can a lawyer confidently and reliably process a plaintiff’s claim for damages arising from bodily injury when he or she doesn’t know the technical cause of the accident and from that the party(s) responsible?  The emphasis is on confidently and reliably because lawyers are doing it now and managing often enough.  But that’s not good enough.

Establishing causation involves a two-stage inquiry: (Ref. 3)

1. The first stage involves establishing ‘factual’ causation.  That is, determining exactly what happened and who might have been involved in the incident.  This is the forensic engineering investigation.
2. The second stage involves establishing ‘legal’ causation.  This is when a lawyer reviews the factual causation – after it’s been established, and determines if the law is involved in the incident.

Determining factual causation in cases like the following is not lawyer-work.  It’s not even in the engineering text books in some cases and for certain not in the medical and legal text books.  A forensic engineer often has to “figure it out” as he goes along.

And often enough there is more than one party involved in what happened.  These parties are not known until the engineering investigation is complete.  I’ve seen the wrong party named in cases that were filed months, sometimes years before I was retained to investigate an incident.

Some examples of personal injury cases:

• I used a piece of pork belly – a pig’s belly skin, to investigate one slip and fall accident,
• also showered and walked across an accident site dripping water from my bathing suit to learn where water on a floor came from,
• investigated soap detergent on a stair landing at a retail outlet,
• carried out full scale field tests in a fatal motor vehicle accident,
• planned full scale tests using a Hollywood-style stunt man in a fatal step ladder accident,
• researched how a building “breaths” in one toxic fumes emission case and
• how fuel oil weathers in the ground in another, and,
• used binoculars to establish the cause of a man’s head injury from falling ice.
• a colleague investigated a trip and fall accident where the injured party was half-running backwards

Cases like these don’t get resolved until the technical issues are identified and investigated.  One of the above cases went on for 11 years then settled in 4 months after I completed my engineering investigation and established cause.  Many months to a few years is normal.  For sure, some of the delay is due to short comings and backlog in the justice system but not all.

I’ve seen similar situations in cases involving structural deficiencies and engineering failures and collapse in the built and natural environments as distinct from personal injury accidents.

Until the technical issues are identified and investigated thoroughly, technical causation established and the involved parties identified, the doctor’s view of medical causation might suffer for lack of some technical data.

And the practicing plaintiff lawyer won’t know who to sue, confidently and reliably – he could well be out on a limb.  To borrow and modify a comment in the description of the conference topics, “Don’t let (missing data on technical) causation sink your case”.

A three-part topic on causation is needed at the conference in St. John’s in June – medical, legal and technical – if the APTLA membership and their plaintiffs are to be even better served.

References

1. Sebald, Jens, Phd, System Oriented Concept for Testing and Assessment of the Slip Resistance of Safety, Protective and Occupational Footwear, Pro Business Gmbh, Berlin, 2009
2. Di Pilla Steven, Slip, Trip, and Fall Prevention, a Practical Handbook, 2nd ed., CRC Press, New York, 2010
3. Wikipedia, April 12, 2016

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.