The Defendant’s counsel prepares a Statement of Defense that replies to each allegation made by the Plaintiff.  The Defendant may file counter-claims and also claims against third parties with the court.  The Statement of Defense sets out the facts and the legal grounds that the Defense is relying on in their reply to the Plaintiff and in their allegations against the Plaintiff and third parties.

The Statement of Defense is the third step in the Pleadings:

• Notice of Claim
• Statement of Claim
• Statement of Defense
• Affidavit

A professional engineer retained by the Defense might focus on the following in his or her forensic engineering investigations:

• Review the technical evidence supporting the Plaintiff’s claims
• Carry out engineering investigations to confirm or refute the Plaintiff’s investigations
• Carry out engineering investigations of perceived wrongs and damages that could give rise to counter-claims and cross claims
• Assess the technical strengths and weaknesses of all parties

Once the last of the Statements of Defense have been filed, including any amendments, – one for each party, the pleadings are said to be closed.

The parties involved in the dispute may now exchange informal letters to try and come to an agreement and settle their differences before proceeding with a number of other steps.  In a sense, the clock starts ticking at this point in the countdown to going to trial.

The role of a professional engineer retained by the Defense at this stage would be similar to that of a professional engineer retained by the Plaintiff:

1. Visit and visually examine the site
2. Review the technical facts given in support of the Plaintiff’s claim and the technical evidence supporting these facts
3. Review available documentation and evidence of lay witnesses, and experts and specialists
4. Identify and explain the technical issues in the allegations in the Statement of Claim
5. Carry out engineering investigations to confirm or refute the thoroughness and reliability of the Plaintiff’s investigations and the evidence and facts arising from these investigations
6. Assess the technical strengths and weaknesses of the Plaintiff’s case and for each party identified by the Plaintiff
7. Identify the technical facts relevant to the Defense’s position and the evidence supporting these facts
8. Assess if enough technical data is available for the Defense to respond to the Statement of Claim
9. Assess the technical strengths and weaknesses of the Defense’s position
10. Carry out engineering investigations for the Defense of perceived wrongs and damages that might give rise to counter claims and cross claims
11. Evaluate preliminary design and costs of repair of the damaged structure
12. Identify parties that could be involved in the engineering failure or accident that have not been named in the Statement of Claim, the Defense, or any counter claims and cross claims
13. Review the Statement of Defense and counter claims, and response to Statement of Claim, for correct understanding and representation of the technical issues and facts 
14. Prepare a report, on instruction of counsel, describing the forensic engineering investigations, the analysis of the data collected, the findings, the conclusions, and the opinions formed relevant to the Statement of Claim’s allegations, the Defense’s response, and counter claims and cross claims

References

1. Steps in the civil litigation process.  Published August 28, 2012
2. The role of a professional engineer in counsel’s decision to take a case.  Published June 26, 2012
3. The role of a professional engineer assisting counsel prepare a Notice of Claim.  Published July 26, 2012
4. Stockwood, Q.C., David, Civil Litigation, A Practical Handbook, 5th ed., 2004, Thompson Carswell
5. ASCE Guidelines for Forensic Engineering Practice, 2003, American Society of Civil Engineers

They seem mysterious and frightening – Sinkhole!, suddenly appearing in the ground and “swallowing” things at the surface.  Like quicksand and all of a sudden there but, in another sense, not like quicksand which you maybe can see ahead of time and walk around.  Swallowing things like entire cars as shown in the picture on page A4 of the Globe and Mail yesterday.

The picture was of the rear of a vehicle just showing above the paved surface of the Highway 174 off-ramp at Jeanne D’Arc Boulevard in Ottawa.

The hole was deep enough that almost the entire length of the vehicle was in it, wide enough to take the width of the vehicle, and the width of the lane long.  A fair size hole to suddenly appear in the highway.

The traffic lane appears to be one of at least four lanes, two of which are at a lower level.  The lower lanes appear in the upper, right corner of the picture.  The lower lanes glisten with water.

We don’t expect this to happen in our highways, and particularly in the natural environment if the source of the problem lies there.  Seemingly natural events like this destroy our fundamental assumptions about the safety of the world (Ref. Janoff-Bulman).

But events like this are not so mysterious and their occurrence can be fairly easily predicted, but, unfortunately, not so easily the timing and location of their occurrence.

A forensic engineer investigating the cause of this sinkhole might consider four elements to the problem even before leaving his office (I’m pretending I’m the engineer and just got the call and haven’t even seen the site, but know about structures in general):

• Conditions in the terrain where the highway off-ramp is located
• Foundation soil, bedrock and groundwater conditions in the highway subgrade,
• Roadbed design and construction, and,
• Road and infra structure maintenance

As soon as a professional engineer gets to the site and does a visual assessment (see posting, September 4, 2012) he might well refine this listing but I don’t think a lot.  The visual assessment would draw the engineer’s attention to any unusual conditions in the terrain beyond the highway.  Conditions like evidence of heavy rain and its effects, flooding, nearby construction works that have impacted the road, etc.  The engineer is likely to have checked the recent weather reports for the area.

Seeing nothing unusual the engineer is certain to hyposthesize initially that the problem lies with the infra structure buried in the roadbed, service pipe work of some sort.  Like storm drains and water supply distribution pipes.

He might form this hypothesis based on evidence such as the following:

• Finding no unusual conditions in the terrain where the highway is located.
• The reasonable assumption that the highway roadbed has been properly designed and constructed.  We expect this of our highway departments.
• The rectangular shape of the hole in the road opening to the lower lanes on the right.
• The finite depth of the hole: 5 feet, 10 feet, 15 feet?  Depths that approximate those at which service pipes are placed.
• What he sees in the hole on looking in.

The forensic engineer might reason that the location of the hole and its shape are typical of those that might form when a water main bursts.  The escaping water seeks the easiest path down and out to the right eroding the roadbed as it flows.

Of course he would look in the hole once at the site.  If he sees a burst pipe discharging water then he’s reasonable in assuming he’s solved the problem of what caused the hole to form.

If he doesn’t see a burst pipe then he will start to think of other possibilities while waiting for documents on the existence and location of buried infra structure in the roadbed.  It’s possible there is a burst pipe but it’s buried deeper and not visible in the bottom of the hole.

One possibility is the types of natural soils and rocks forming the subgrade or foundation of the roadbed.  If he has geotechnical engineering experience he would want to know if the area of the road is underlain by Karst terrain. This is a type of terrain formed on rock like limestone that dissolves in the presence of water forming different types of solution cavities – like sinkholes, for example.  Or ‘roofed over’ sinkholes that are just about to break through like the banana holes in the Bahamas.  There is Karst terrain in the Windsor area of Nova Scotia.

Karst terrain has a certain appearance at the surface and the forensic engineer would look for this while waiting for a copy of the geotechnical report for this section of the highway.

So, the forensic engieer would form different hypotheses during his investigation of the sinkhole – the hypotheses above and possibly others, investigate each in turn with site work and information from documents until he arrives at the cause of the sinkhole.  The sinkhole wouldn’t be a mystery to him.  It would be a problem with a solution that he would be confident he could find.

For certain, professional engineers with the Department of Highways in this area are working on the problem now.  They would follow procedures like I’ve outlined above – consciously or unconsciously forming and revising hypotheses and checking them out.

The hole formed in the road and the vehicle drove into it on Tuesday.  Based on my experience of these things, I’m certain they have already solved the problem.  It can be that quick in forensic engineering.

References

1. Janoff-Bulman, R., Shattered Assumptions: Towards a New Psychology of Trauma, The Free Press 1992
2. Jorden, Eric E., “Technical” visual assessments: Valuable, low cost forensic method, posted September 4, 2012

I posted an item recently about an accident that injured four people when they were struck by flying pieces of metal from a ride in Yarmouth, Nova Scotia.  I thought, based on what I read in the paper, that it was an accident that might be adequately investigated on site by means of a simple visual assessment of exposed surfaces.

(See, “Flying objects, injured people, and forensic engineering investigation”, published August 3, 2012)

A visual assessment doesn’t sound very technical but it is always carried out at the start of even the most complex investigations, and sometimes it is all that is necessary for the simpler ones.  It can be thought of as “calibrating” the forensic engineer to the site (Ref. Sowers).  If little else is necessary by way of investigation then it can be quite a low cost investigation.  If more is necessary then it helps ensure a thorough, reliable, cost effective forensic engineering investigation.

A visual assessment is an essential part of the main steps in the failure investigation process:

• Acquisition of data
• Analysis of data
• Formulation of opinion

A visual assessment or examination involves simply looking – by whatever means, at what you can see in the exposed surfaces at the scene of a failure or an accident.  This as opposed to taking things apart and looking below the surface – an intrusive examination.

Forensic engineers sometimes go right up to an object and look at it with a hand held lens – I examined the fibres in a crack in concrete one time that told me when the crack was formed.  Other times we simply walk the site and look at the failed structure or an accident scene from a few feet off.  We take some measurements and a few photographs, and make sketches and notes.

We can also look at an object with binoculars (see below), and also with the telescopic lens on a camera – and study the exposed surfaces later as recorded by the camera.

A visual assessment, in a sense, can also mean examining the images of surfaces in photographs including photographs in documents provided by counsel (see below).  But, you can’t beat being “at the scene” and getting a feel for the situation with a site visit and a good look, a good poke around.

In the earlier article, I explained why I thought the visual assessment approach was possible and valuable in Yarmouth and gave an example from my own pracitice.  Of course, as soon as I published my article I thought of other good examples of visual assessments I’ve carried out.  Some of these are described below:

1. Flying Metal– In Yarmouth I noted that the exposed surfaces of different units on the ride (chairs?) would lend themselves nicely to a visual assessment of what caused the metal to come loose.  Having a number of chairs the same on the ride, presumably some with the metal still intact, would allow a valuable before-after assessment.

2. Falling Ice– I investigated the cause of ice falling and injuring a person solely on the basis of visual assessments.  This involved an examination from the ground surface of the exposed exterior surfaces of the lower level of the structure and the upper levels from a distance using binoculars. I looked at some photographs that recorded the position of the ice on the ground after the accident.  I was also able to carry out a before-after assessment in this case somewhat similar to what might be possible in Yarmouth.  It helped to look at how ice formed on other structures during the winter.  Application of some basic principles on how ice forms and melts coupled with observations from the visual assessment identified the cause.

3. Retaining Wall Failure– A quite high gabion retaining wall failed on the shore of Bedford Basin, Nova Scotia (a gabion is a wire basket filled with rock).  A part of the wall just fell over onto the shore during the backfilling stage.  Another part remained upright where it was connected to an anchor of sorts that prevented the wall falling over.

A site visit and visual assessment, comparison of the collapsed and upright sections of wall – the before-after comparison that forensic engineers like so much, and application of a well known rule-of-thumb in retaining wall design quickly identified the cause of the wall failure.

4. Tank Collapse – I was asked to establish why a fuel oil tank collapsed into a trench by examining photographs only and reading the documents – a visual assessment by remote.  I was instructed not to visit the site not even to drive along the road adjacent the site.

I examined the site as portrayed in the photographs, studied sketches prepared by other professional engineers – during a visual assessment, checked rainfall records, applied some very basic scientific soil mechanics principles and established the cause.

Explaining the scientific principles and the mechanism of failure was a bit of a challenge but I was pleased with the result and the clients said they understood.

5. Soil-Steel Bridge Failure – I investigated the reason a large corrugated steel culvert suddenly collapsed injuring a car driver.  The culvert carried a highway over a stream.  A culvert more than 10 feet in diameter in north America – in this case spanning or bridging about 22 feet, is defined as a bridge.

I was retained two years after the accident and after the collapsed bridge had been removed and a new bridge constructed.  Several different engineering investigations were carried out including detailed examination of photographs taken at the scene on the day of the failure – a visual assessment by remote.

The examination established the cause quite quickly but couldn’t completely discount a hypothesis of failure put forward by the defence.  Until a detailed topographic survey provided additional evidence that, coupled with data from the photographs, clearly showed why the hypothesis was not valid.

This was a costly forensic investigation because of the different modes of possible failure that had to be investigated and discounted and the fact the debris had been removed by the time I got there.  At the end of the day it was the visual examination of the exposed surfaces in the photographs taken at the scene and the results of a simple topographic survey that established the cause.

6. Fatal Step Ladder Accident

A simple visual examination of the scene of a fatal step ladder accident established that a re-enactment of the accident using stunt men was the best way to determine if a flaw in the ladder was the cause of the accident.  The first forensic method was inexpensive, the follow-up forensic method not so much by a long shot.  Fortunately, the case was resolved without proceeding to the costly and risky re-enactment.

7. Flooding Problems – I see quite a few engineering failures involving poor drainage and the flooding of land and the basements of structures.  Investigation relies on different methods, most notably establishing how the structure has been designed and constructed and the site topography – the lay of the land.   All investigation starts with a visual examination of the scene.

One of the most valuable investigations is an examination of the structure and the land before, during and after heavy rain – a visual assessment of before and after runoff and flooding conditions at the site.

In one instance, an initial visual examination that occurred during heavy rain suggested that flooding was not in fact occurring as thought by the client, contrary to the findings of very expensive investigations by others.  And in addition, another slightly different visual examination that could have been carried out years earlier would have established one way or the other if flooding was occurring – very unlikely, and saved the client many 1,000s of dollars.

 ***

Visual examinations don’t sound very technical but this simple method reduces forensic engineering investigative costs even when more complex investigations are seen to be necessary subsequently.  And simple visual examinations of exposed surfaces sometimes demonstrate that the complex investigations aren’t necessary – and weren’t necessary in some cases.

References

1. Sowers, George F., Introductory Soil Mechanics and Foundations: Geotechnical Engineering, 4th ed., MacMillan Publishing 1979