We learn when things fall down or don’t work as they should.  We learn from mistakes – our own as well as those of others.  I see these lessons in the engineering failures and personal injury accidents that I investigate.

There is an element of judgement in the practice of engineering.  Particularly those engineering disciplines based on the semi-empirical sciences.  Disciplines like geotechnical, foundation, earthworks, environmental, and hydraulic engineering.  Good judgement comes from lessons learned.

We also learn when things stand up – when we get it right, particularly from structures that are still functioning after many years.  Things that stand up and work for a very long time.

I thought of this when I learned about the government’s plans to try and sell the Porter’s Lake Canal to developers who would fill it in and build houses on it.  Heaven forbid.  The Canal is functioning today almost as intended by engineers and builders when planning first began more than 135 years ago.  (Fortunately, the Canal has since been taken off the market by Fisheries and Oceans Canada as a result of public feedback)

The Canal is a hydraulic structure.  It connects 18 mile long Porter’s Lake in Nova Scotia to Three Fathom Harbour on the eastern shore.  You cross it when you travel highway 207 between the communities of Seaforth and Three Fathom Harbour.  It forms an unofficial boundary between the communities.

Porter’s Lake Canal is a little more than 0.5 miles long and was designed to be six feet deep at mean low tide.

It’s also pretty enough when you paddle or hike it’s length.  It looks like a hockey stick from the air.  Can you get any more Canadian, more Nova Scotian than that?

The Canal’s straight alignment stands out as an unusual feature in the landscape from several thousand feet aloft – go see, obtain a published aerial photograph of the area taken from 6,000 feet (at the Geomatic’s Centre in Amherst).  I’m sure it would stand out on the moon with a good telescope.

It was planned, designed and constructed by the community, engineers and builders in the late 1800s. The Provincial Engineer reported on the feasibility of the Canal in 1878.  It was intended to provide better and more reliable access to the sea from Porter’s Lake for quite small coastal schooners – and markets for the natural products along the shores of the lake at the time.  Rocky Run, the natural access to the sea from the lake, kept filling up with gravel from the action of the surf and the heavy seas of the Atlantic Ocean.  It was dredged several times.

The Canal hasn’t filled up in all those years, a main requirement the engineers had to meet.  Engineering judgement would have been important in selecting Three Fathom Harbour as the location of the discharge end of the Canal, also in designing the slope of the Canal sides and the depth.  Scour and erosion, long shore drift, and slope stability are quite empirical engineering studies even today.

The lesson learned is that engineering judgement and somewhat un-glamorous empirical knowledge are valuable elements in designing and building structures that can last a long time.  A very long time – witness the still functioning Roman, multi-level, bridge-like aqueducts.

Like the Shubenacadie Canal in Nova Scotia of similar vintage, the Porter’s Lake Canal wasn’t used to the extent intended for similar reasons – new technology overtook both of them.  A bridge constructed over the Canal shortly before 1915 to carry the railway to Upper Musquodoboit was too low for even small coastal schooners to pass under.  Porter’s Lake Canal as a commercial venture was doomed at that time.

There are photographs of the Canal In Appendix 1 and additional, quite interesting historical information in Appendix 2.

The first photograph is of a paddler preparing to canoe the Canal.  CBC TV did a feature story on the public’s efforts to save the Canal.  The photographer in the middle distance is likely with CBC TV.

The second photograph is a view of the Canal from the Canada Trail where it crosses the Canal.  Hwy 207 is in the distance.

The third, rare photograph is of the Canal under construction.

Citations

Much of the information on the Porter’s Lake Canal including the photographs has been provided by Dusan Soudek, Halifax, an avid outdoors-man, who, I think, has a day job in medicine.  It was Dusan, possibly assisted by others, who located the following published items from the The British Colonist 1871.  My initial thoughts on the Canal on reading some of Dusan’s material is also included below.  It’s all quite informative reading on a very interesting engineering structure right under our noses – a short distance outside of Dartmouth.

Appendix 1

Appendix 2

The Porter’s Lake Canal

The value of this great improvement is not generally understood. It may be briefly, summed up as follows. Porter’s Lake is about eighteen miles in length, and surrounded by farms and woodland, and there are large quantities of building-stone and sand, all of which would prove valuable sources of wealth, if vessels of moderate tonnage could have free access to the ocean. But, unfortunately, the natural outlet from the lake is directly from the open sea-board, and, from the action of the surf, is being constantly filled up with gravel, although it has been dredged out several times. By cutting a canal from the lower part of the lake to Three Fathom Harbor, an outlet would be obtained which would never be liable to be choked up, as the harbor is sheltered from the heavy seas of the Atlantic.

The distance from the lake to Three Fathom Harbor is a little over half a mile, and from the nature of the soil could be cut of the depth of seven feet, which is as deep as is necessary, for an estimated sum of two thousand pounds. Were this accomplished, the whole of the great resources of the surrounding district would be developed, and the value of all the properties enhanced. For many years the residents have been hoping to obtain this important boon, but without success. We are happy to know, however, that at length they are in a fair way to secure it.

The residents of the district signed a petition to the Dominion Government asking for aid towards the work, which the Government have promptly responded to by sending an engineer to make a survey and make a report on its practicability and probable cost. There can be no doubt of the nature of the report on both points. Mr. Fairbanks has already, at the request of the inhabitants, made a preliminary examination, and his report proves not only the entire practicability of the work, but the very moderate amount necessary to effect it – not probably exceeding 2 000 pounds. Should the Government Engineer’s report corroborate Mr. Fairbanks’s (of which there can be no doubt) the work will be undertaken and completed by the Dominion Government, and a great and lasting boon thus conferred on the people residing in that part of the county.

(unsigned editorial, The British Colonist (Halifax), May 6, 1871)

Porter’s Lake Canal

This important public work is now demonstrated to be practicable. It can be constructed, and must be. The persons who sneer at the enterprise and regard it as an electioneering dodge would of course kill it off if they could. The matter is in the hands of the people.

(unsigned editorial, The British Colonist (Halifax), May 6, 1871)

That Canal

The Government Candidates with “Hon. William Garvie” at their lead continue to sneer at the Porter’s Lake Canal. They call it a “canard,” a “dodge,” an “invention,” a “piece of deception,” a “walking falsehood.” What more names they may have for it we do not know; but we know that the project is a wise one, perfectly practicable, quite within reach as to the means for its construction. We know further that the people most deeply interested in it, the inhabitants of the district, do not regard it as a “walking falsehood.” What do they or we care for second hand Theodore Hook stories? We are grappling with practical realities. We all know that the Canal will not be encouraged by the Local Government or its nominees. We do not wonder then that the people around Porter’s Lake are determined to support Messrs. Hill, Daly, and Geddes.

 (unsigned editorial, The British Colonist (Halifax), May 9, 1871)

Eric,

thanks for your intriguing thoughts about the canal. I am sending you, separately, a rare photo of the canl while it was being excavated and my notes about its history. It is shaped like a hockey stick… Can you get more Canadian than that?

In late 19th century the Dominion government was plagued by storms silting up Rocky Run, the natural outlet of the lake, trapping schooners in the lake for weeks. At one point the feds were working on three separate outlets for the big tidal lake. The site chosen for the current canal was superb; it hasn’t silted up for a century and likely never will… Regards,

Dusan 4/11/14

You know, Dusan, the Canal is a quite striking engineering structure.  Straight and true, covering a lot of ground, built by men long ago with far less sophisticated earth moving, mechanical equipment than available today.

Not such a complex structure in engineering terms but still an old structure built by man.  Not in the same league as the Shubie Canal but respectable enough, if for no other reason but that it’s about 100 years old, just a little less than Shubie.

And it’s being used today.  How many 100 year old engineering structures are being used today in Nova Scotia, other than a very few buildings, a very few wharves, and a few winding, twisting roads?

We have two main environments that figure in the affairs of man, a natural environment and a built environment.  This is a good example of a different structure in the built environment – something other than buildings, that represents the efforts of men.

And don’t forget, mankind has the built environment and all the comforts associated with it – I know, some problems too, because of the engineering profession, and the forebears of engineering centuries ago, builders in general.

And it’s an interesting structure that got built by our forebears.  Unlike the planned canal across the Tantramar Marshes that didn’t go anywhere because it didn’t get built.  But like the Shubie Canal that did get built.

But, unlike the Shubie Canal in that, to some extent, it’s being used today to something akin to its intended purpose long ago.

And it’s so striking from the air – in the aerial photograph, like an arrow shot across the landscape.  A feature like that draws the attention of those of us aloft.

You know, a structure like this – the Porter’s Lake Canal, just might show up on a photograph taken from the moon or Mars.  And it would draw the attention of Martians because it is an unnatural feature.  Bet your boots, someone is up there looking down on us.

More seriously, but only a little, this structure does show up from some distance off in space; there’s no question about that.  In view of that, I think, rather than abandon the Canal to real estate developers and someone’s bottom line, we should clear the forest growth back a little, just a little, so it is more visible from the air, be more inviting to paddlers, and be another feature that marks Nova Scotia as different from the rest of the east coast.

Dusan, feel free to share my e-mail thoughts with others with the view that it might stimulate additional thoughts of theirs, sorta like in a brain storming session.

Okay, take care…Eric 4/11/14

Eric,

think much smaller coastal schooners, not the Bluenose. it may have been meant for logs, too. There is a mention in the old documents that it was to be 6 feet deep at mean low tide.

I forgot to mention the name of the trail on the former rail right-of-way: The Atlantic View Trail, now a portion of the Trans Canada Trail. Regards,

Dusan 17/11/14

Hi Eric,

the road that crosses the canal is Highway 207, and the canal forms the unofficial boundary between the communities of Seaforth and Three Fathom Harbour.

In my initial appeal I made a slight error. The concrete railway bridge that spans the canal has the date 1928 imprinted in it, so I assumed that the Musquodoboit Railway reached the canal in this year. In fact the line, between Dartmouth and Uppper Musquodoboit, was officially opened on July 1, 1915. The original railway bridge over the canal was a wooden trestle, to be replaced  by the current concrete bridge later.

So no schooners could pass under the low railway bridge as early as 1915, and the canal was doomed as a commercial venture then.  An 1878 report by the Provincial Engineer on the feasibility of a canal mentions the need for a “pair of small lock gates.” Regards,

Dusan 16/11/14

I have some great news to report. In response to public feedback, Fisheries and Oceans Canada has taken the canal property off the market, giving interested parties some breathing room to make plans for the canal’s future. It was discussed at this week’s HRM’s Harbour East – Marine Drive ( i.e., “Dartmouth”) Community Council meeting and is on the agenda for Tuesday night’s (November 18) HRM Regional Council meeting. (Agenda Item 11.3.5).

If you haven’t sent a note to the HRM Councillors re your support for keeping the Porters Lake Canal in public ownership and if you are inclined to do so, please consider sending a brief note to District 2 Councillor David Hendsbee at hendsbd@halifax.ca and to the entire Council at clerks@halifax.ca before noon on Tuesday.

Dusan Soudek 16/11/14

N.B. The sign on the former railway bridge that crosses the canal – see attached photo– disappeared sometime after Hurricane Juan..

Hi Lyse,

excellent! Kevin Murphy, the local Liberal MLA is also the Speaker of the House. He is getting forwarded messages of support for the canal from Councillor Hendsbee, who is also forwarding them to all the other HRM councillors and various provincial politicians. I am getting some of them, too. And, boy, there have been lots of them. The word is spreading… It never hurts to cc as many politicians as possible. There are plans to set up a “Save Porters Lake Canal” Facebook group in order to keep people abreast of developments and to have a place to post historical press clippings, photos, videos, etc.. Regards,   Dusan Soudek 5/11/14

Is there something that we should talk about that prevents carrying out a thorough forensic engineering investigation? Or at least acknowledge that it’s an issue?  We counsel and forensic engineers and scientists, the justice system’s experts?

(There is something.  And Judge John Sopinka, Supreme Court of Canada, had the solution in 1995: – retain an expert “…early in the life of a case”)

The elephant

I’m thinking that what needs to be talked about – the elephant – is inadequately funded forensic investigations and the reason for this.  Actually, not so much inadequately funded investigations, but learning about the inadequacy after some preliminary forensic work has been completed and invoiced.

Work like an initial reading of the documents and a visual examination of the site. Work at the real front-end of an investigation that identifies the key tasks that must be carried out to properly address the technical issues.

For certain, the preliminary work sometimes indicates the direction an investigation will go – the likely cause of a failure or an accident, but that’s a bonus if subsequent investigation confirms the initial assessment.

In a sense, there’s nothing wrong with having inadequate funds – there are limits to everything.  We know that justice is expensive in our society.  It’s finding out about this expense after the investigation has started – usually, at the very least, several months after counsel has taken the case, and sometimes – too often, years after.

Suddenly, it’s learned that forensic investigation can be expensive.  And this greater expense was not known when counsel took the case and assessed the worth of the file to the practice or estimated the costs to the client.  Suddenly, the worth of the file or the client’s budget is being threatened.  This is difficult to talk about.

What happens then?  Often enough, counsel decides against further investigation. Sometimes without finishing off with a simple calculation – a few hundred dollars in additional fees in one case I know of that would resolve a key issue and technically strengthen a case immeasurably.

Another time without doing a simple high school averaging of measurements to quantify what both plaintiff and defendant observed during field tests.

And, most sadly of all, a case where the technical data from preliminary forensic work clearly and easily demonstrated that counsel is suing the wrong party.

Where did the elephant come from?

He was on the move as soon as the case was taken

The expense often wasn’t known because an expert wasn’t consulted about forensic investigative costs when the case was taken by the legal practice months or years before. The elephant was on the move then.  All that was needed after that – to get the elephant in the room, was some preliminary forensic work and then an invoice.

This doesn’t help

It doesn’t help when counsel estimates the cost of forensic work by looking at past expert costs for different cases, forgetting that you’ve got to compare apples with apples when assessing costs.  You’ve got to know the tasks involved in an investigation and the cost to carry them out.  These tasks and costs vary for the different kinds of forensic investigation.

The cost of some cases

The fees for one of my cases was $1,300.  My involvement quickly stopped the hemorrhaging of the client’s funds which had reached $140,000 for various experts in two years – engineers, a scientist, a land surveyor, and lawyers.  All, including the lawyers, were being guided by one questionable, revenue-driven, technical “expert”.

At the other end of the scale, fees and expenses for another case were about $83,000 to investigate the catastrophic failure of a bridge and permanent disablement of a driver. The site was a five hour drive from the office and several visits were necessary.

Similar costs were incurred investigating the inadequate underpinning of a structure – the more we investigated, the more problems we found to be followed up on.  But, another inadequate underpinning problem cost quite a bit less, about $37,000, to investigate and oversee repair.

A landslide that affected several properties cost $44,000 in fees and expenses.  A flooding problem, $10,500.

The preliminary investigation of a fatal MVA cost $33,000 – just the preliminary work.  But it was subsequently found that this work was enough to answer the one technical question: – did a pile of soil on the highway contribute to the accident?  I was glad because the field testing was dangerous; I had put the testing on hold pending getting safety measures in place.

If memory serves, a good many forensic investigations seem to cost between about $5,000 and $35,000.  I’m sure experienced civil litigators handling more complex cases see a similar spread to the cost of experts, with the occasional rogue case coming in considerably higher – or lower.

For non-technical counsel to estimate the cost of an expert for a new case based on such a spread – with the occasional rogue in the wings, is asking for trouble.  Best that the technical expert take the risk and do the estimating early.  And there is risk for the expert in estimating costs considering the difficulty in doing this. (Refs 1 and 2)

The justice system and engineering guidelines say, in no uncertain terms, “Do thorough investigations!”

We are also required by guidelines published by our learned societies and associations, as well as by the justice system, to be thorough and exact in our engineering and scientific investigations.  This takes time which must be taken into account when estimating the cost of a forensic investigation.  If we don’t the elephant inches closer to the room.

The same as counsel is required to take time and to be thorough in their legal investigations. This if the client is to be well served by the justice system.  Sometimes – actually quite often, really, there is no case to argue or it’s weak until the technical questions have been answered.

Getting rid of the elephant

How do we get rid of the elephant, get him out of the room?  How do we prevent the surprise of inadequate funds after some preliminary forensic work has been completed and invoiced?  How do we prevent the threat this poses to the worth of the file to the practice or to the client’s budget?  How do we prevent short-circuiting a thorough forensic engineering investigation?

It’s not easy – the cost of forensic work is notoriously difficult to estimate. (see again Refs 1 and 2, also Refs 3 and 4)  But retaining an expert at the time a case is considered – rather than months or years later, will at least get you informed advice on the cost of forensic work, including the difficulty estimating costs and the possibility of surprises later.

Judge John Sopinka, Supreme Court of Canada, was clear about this in 1995 when he recommended: – retain an expert “…early in the life of a case”.  (Ref. 5)  This because of the complex issues that counsel, the courts, and the justice system had to deal with at the time, and just didn’t understand.  Society is even more complex today.  And David Stockwood Q.C. echoed this advice in 2004 in the 5th edition of his well regarded text, Civil Litigation: A Practical Handbook.

If we do this – retain an expert early, the elephant will not get in the room.  We will all be on the same page talking to one another about the real cost of forensic investigation early in the case.

It was the breadth of the human failings that shocked me.  Not the fact that human failings played a part in the collapse – they do often enough when a structure falls down.  What troubled me is that they ran much of the gamut of our darker side, including incompetence and greed, and were exhibited by all parties involved with the mall in it’s 33 year life.

(On the flip side, however, I was impressed by the thoroughness of the judicial investigation.  Also, with the commissioner shooting from the hip and telling it like it is after the findings were in.  Nice that)

If there is a common denominator in the human failings a case could be made for “money” being the one – getting and keeping as much as you can.  Nothing wrong with money except when it blunts your moral and ethical fibre and gets in the way of doing the right thing.

It`s not difficult to believe undue interest in money was there decades ago during the planning of the mall – the developer wanting the most structure for the least money spent.  Then fast forward to a few weeks before the collapse when the engineer signed off on the structure knowing it was unstable – for certain with a view to being retained again and being paid for his services.  And the undue interest in money on the part of the many private and public parties involved in the mall each year over the decades right up to the collapse.

(Be assured: In all my years, I’ve never heard of a professional engineer deliberately falsifying his report.  I’ve been around the block a few times and seen a few things but never this)

We can be excused for wondering how many other structures are on the verge of collapse that we don`t know about – due to similar human failings.  We know about the mall because it fell down.  There are bridges on the east coast that are in poor condition.  But we know about these and the problem is being addressed.  What about the structures that we don`t know about?

I blogged a couple of years ago – shortly after the mall collapsed, about construction inspection and maintenance being the Achilles’ heels of project development, and touched on it again a few weeks ago.  Inadequate construction inspection is almost like a default human failing.  But this singular weakness in project development is not of the breadth and blatancy of the human failings that brought the mall down.

We have our problems in forensic engineering investigation – a development project in a sense to an engineer, where investigations “fail”, that is, they are inadequate because of human failings on the part of owners, counsel, and engineers.  The parties often failing by taking little interest to understand what’s involved in forensic work and that thorough and objective investigations are expensive.

We can’t always prevent the tragic effects of human failings on the built environment any more than we can prevent sick people murdering soldiers and shooting up our parliament.  We must recognize and expect that these tragic events will happen – human nature being what it is, learn from them, and press on.

It helps to focus on the fact that there are few structures in the built environment that are in grossly poor condition and on the verge of collapse.  Fortunately, very, very few, I believe, knowing the engineering profession as I do.  At the same time, however, to recognize that there are some structures in poor condition – but not about to collapse.  Structures that are malfunctioning, performing poorly, and costing money that someone would like to keep and hang onto.

We investigate a considerable variety of accidents and engineering failures.  No two are exactly alike.

Also, our work is ‘small’ and ‘medium’-sized as opposed to ‘big’ and newsworthy.  Not like the collapse of the Elliot Lake Mall in June 2012.  Nor like the landslide in Oso, Washington in March of this year.  We investigate tragedies like these but fortunately infrequently.

The various failures and accidents also stretch across different engineering disciplines.  For example, civil engineering and related specialities like foundation, geotechnical, and environmental engineering, and also structural, electrical, and mechanical engineering.

Similar for civil litigators and insurance personnel? 

I can easily imagine that this variation is not too much different from the mostly no-two-are-alike, small and medium size cases civil litigators handle in Atlantic Canada.  Also those files handled by insurance claims managers, consultants, and adjusters.

(If you are quite busy you can get a quick idea of the variety – just in the forensic civil engineering field alone – by scanning the 16 thumbnail sketches in the list below.  There are links in the References to detailed descriptions of four cases)

I thought to blog on this question when I was recently asked by counsel to briefly describe some of the engineering failures and accidents that I’ve investigated.  I noted 22 individual cases including a couple that were newsworthy.  I was struck by the variety.

Getting an idea of the magnitude of the variation in forensic work

To get some idea of the magnitude of the variation in forensic engineering investigation you might first look at a blog I posted a few weeks ago on the different ways buildings can fail – 34 and counting. (Ref. 1) The author of the book that prompted the earlier blog missed a good number involving the structural and foundation failure of buildings.

Then think about the fact that a building is just one type of structure in the built environment that can have a problem.

Our built environment comprises hundreds of different structures.  For example, bridges, dams, wharves, roads, railways, embankments, transmission towers, power stations, drainage systems, retaining walls, and all the attendant infra structure and mechanical and electrical services.  All have their long list of different ways of failing.

A step ladder is a structure to an engineer.  Also a pile of salt on the road, particularly if it’s a factor in a fatal motor vehicle accident.

Risk of personal injury accidents

It’s not difficult to imagine with such an elaborate and complex built environment that there is also considerable risk for different types of personal injury accidents to occur, as distinct from failures.

For example, there is an extensive literature just on slip, trip and fall accidents alone – many thousands of these types of accidents occur every year in North America, with a number of these in Atlantic Canada.

Questioning a forensic engineer

All this variation might beg the question, “How can any one forensic engineer know how to investigate so many different types of failures and accidents?”  Well, if we stay within our respective disciplines and specialties – civil engineering for me – we can do it.  The basic investigative principles are the same within a specialty regardless the problem.  I suspect the principles are also similar across the different engineering disciplines.  .

What do we investigate in Atlantic Canada? 

The following categories of cases will give you some idea.  The cases are selected from my files.  Each category represents one to several cases.  The Cases are described, in general, and the kinds of Technical issues that might need to be addressed are noted.

No two cases are exactly alike as noted above, and some are very different.  The floor surfaces in the slip and fall accidents are all different.  And slip and fall accidents are very different from a soil-steel bridge failure and also different from toxic fumes in buildings.  And these in turn are different from inadequately underpinned buildings, collapsing retaining walls, landslides, tunnel failures, and vibrating buildings.

Most of the cases were in Atlantic Canada but two were at airports in the Bahamas.  Four cases did not result in litigation but are quite illustrative of the variation in forensic engineering investigation.

1. Floods:  Cases  Frequent land flooding and drainage problems, and flooding of nearby structures.  (In addition, we investigate many basement flooding problems – too numerous to mention)  Technical issues  Generally, determine whether or not construction on adjacent properties caused flooding and an increase in drainage on adjoining properties.  And, in one case, caused a three foot deep flood in the pump room of a recreational facility with a swimming pool.
2. Vibrating buildings:  Cases  The very odd occasional case like a building that vibrates in winter – not in summer, as occupants walk from one end to another.  And ceiling-wall joints open up in winter then close in summer.  Technical issues  Determining the cause of this odd behaviour.  (Difficult to refrain from telling you that it was due to differential frost action on the foundations)  (Ref. 2)
3. Inadequate remediation of fuel oil contaminated sites:  Cases  Suspected inadequate clean-up of contaminated sites at excessive cost.  Technical issues  Confidential interview of 11 clean-up contractors in Atlantic Canada to determine the problems with clean-up operations, the cause of the problems, and the cause and magnitude of cost over-runs. 
4. Collapsing fuel oil tanks:  Cases  Occasional situations are investigated where a structure is undermined by adjacent construction work.  In one case, a domestic fuel oil tank collapsed into an excavation near the foundation of the tank.  Technical issues  Determine the reason why the ground gave way and undermined the tank’s foundations. 
5. Slip, trip and fall accidents resulting in injuries:  Cases  Slip and fall accidents in apartment buildings, recreational facilities, retail outlets, and on sidewalks.  Technical issues   (a) Appropriateness of the floor surfaces – the skid resistance, for the intended usage of the area.  (b) Source of contaminants on floors – a factor in some slip and fall cases.  (c) Maintenance of an area.
6. Accidents resulting in fatalities:  Cases  Accidents resulting in fatalities on highways, dining rooms, and airports.  Technical issues   (a) Whether or not a structure on a highway was a factor causing a vehicle to run off a highway and over a sea cliff.  (b) Whether or not a defect in a ladder caused a worker to fall.  (c) Which wing of an aircraft struck the ground first. (Ref. 3)
7. Bridge collapses:  Cases   Occasional failures involving the collapse of soil-steel bridges – corrugated culverts spanning at least 10 feet in North America, as great as 20 to 25 feet in some locations in Atlantic Canada.  Technical issues   The cause of the collapse.  And in one case, the flood level of the stream the bridge was spanning.
8. Landslides:  Cases  Collapsing slopes – either catastrophic, a slow movement of a mass of material, or the simple sloughing of surface soil, all damaging other structures at the top, on, or at the bottom of the slope.  Technical issues  (a) The cause of the landslide.  (b) Occasionally, design and overseeing stabilization of the slope.
9. Falling objects:  Cases  Objects falling off different structures, e.g., ice from a building injuring a pedestrian below.  Technical issue  Whether or not construction and maintenance of the structure was a factor in causing the object to fall. (Ref. 4)
10. Toxic fumes:  Cases  Occasional toxic odours in buildings requiring closing off of a part of a building or vacating the building completely.  Technical issues  Determining the source and cause of the toxic fumes.
11. Retaining wall collapses:  Cases  Frequent enough collapse or movement of retaining walls located inland or on the coast affecting the wall or property and other structures above or below.  Technical issues  (a) Determining the cause of the collapse, or (b) damage to property and if the damage is related to a failing retaining wall. (Ref. 5)
12. Swimming pool failures:  Cases  Occasional failure of a swimming pool, for example, by movement of the liner.  Technical issues  Determining the reason a liner floated away from the side of the swimming pool.
13. Excessive foundation settlement:  Cases  Frequent enough cases involving settlement of foundations damaging the structure above or affecting its performance.  For example, in one case, rapid, excessive settlement of a swimming pool – many inches in a few months.  And in another case, slow, excessive settlement of a processing plant – many inches in a few years.  Technical issues  (a) Determining the cause of the excessive settlement. (b) Occasionally design remedial work.
14. Inadequately underpinned buildings:  Cases  Frequent enough cases of buildings not being underpinned properly during construction work to fix other problems.  For example, the underpinning of a house associated with remediation of a fuel oil spill.  Also the underpinning of an apartment building during construction of a second multistory apartment building on adjoining property.  Technical issues  (a) In some cases simply determining the adequacy of the underpinning.  (b) In occasional cases, designing and overseeing construction of adequate underpinning.
15. Tunnels:  Cases  Very infrequent case of a tunnel being driven off line.  Technical issues  Determining the cause of the misalignment (In one case I investigated, this was because a very dynamic tunnelling method was completely incompatible with the liquefiable soils the tunnel was being driven through – the saturated soils turned to ‘liquid’ when vibrated)
16. Airport runways:  Cases  A rare case where quite large holes – one to several feet across and deep, were appearing in the surface of a runway.  Technical issues  (a) Determining the cause of the holes – they turned out to be what are called ‘banana’ holes in the Bahamas. (b) Identifying a method to locate potential hole locations. (c) Designing remedial measures.

References

1. How many ways can a building fail? http://www.ericjorden.com/blog/2014/07/10/how-many-ways-can-a-building-fail-and-possibly-result-in-civil-litigation-or-an-insurance-claim/
2. Investigating a vibrating building http://www.ericjorden.com/blog/2013/04/25/investigating- a-vibrating-building/
3. Investigating a fatal MVA http://www.ericjorden.com/blog/2013/03/06/forensic-engineering-investigation-of-a-fatal-mva/
4. Falling roof ice injures man http://www.ericjorden.com/blog/2013/01/18/falling-roof-ice-injures-man/
5. Gabion retaining wall collapse results in litigation http://www.ericjorden.com/blog/2013/02/09/gabion-retaining-wall-collapse-results-in-litigation/

Would I be perceived as biased if I told counsel about literature that discusses both the technical and non-technical issues – including legal issues, of a problem in the built environment?

A while ago, I was assessing the state-of-the-art of a science relevant to a case I’m working on.  I was interested in the factors affecting the test results of a material property.  Also the current understanding in science of this property and it’s determination.

I was also interested in the development of various devices over the years to test/measure this material.  And the accuracy and reliability of devices on the market today.

For me, it was all about the science and forensic engineering.

I was surprised in reviewing a technically, very up-to-date piece of literature on this material property to find it also addressing the interests of owners – and litigators who might be acting on their behalf, in connection with problems to do with such a material.  This literature was current and treated both technical and non-technical issues very comprehensively.

I was also surprised to find in a more dated piece of literature that it was all about the interests of the property owners, the users of the property, and their counsel – and very little about the technical issues.  The title and abstract had misled me.

So, here was very informative literature in which the parties involved in the case I was working on would be quite interested.  And possibly the insight gained would resolve the dispute earlier.

My role in this case was to serve the justice system with reliable technical data and an explanation of this data, and to do this in an unbiased, objective manner.  Counsel’s role is to serve the best interests of their client.

In a perfect world I should be able to inform all parties about this literature.

I’m not sure what would have happened if I had informed my party, and so I hesitated.  If I informed counsel and the information was not distributed would I be perceived as biased?

If I refrained and waited until I was instructed to draft a report on the matter then I would reference the literature as a matter of course.  That would seem to solve such a problem because a report is not usually requested by counsel unless they are comfortable distributing it.  Maybe there was no question about bias.

But still, it`s an interesting question: “Would the expert be perceived as biased if he told counsel about literature of considerable legal interest and little or no technical interest?”

(Posted by Eric E. Jorden, M.Sc., P.Eng. Consulting Professional Engineer, Forensic Engineer, Geotechnology Ltd., Halifax, Nova Scotia, Canada. July 14, 2014 ejorden@eastlink.ca)   

(Note: I posted this blog on June 28, 2014 and updated it since, most recently on October 30, 2020.  The purpose was to help counsel, the judicial system, and insurance claims managers and consultants understand how the standard of care is determined.  To help you gain some appreciation of the technical issues in the stepped process that are understood by an expert but not so well by others.

Also, to draw attention to how the assessment can at times be easy and inexpensive and at other times quite difficult.  This is illustrated with two brief case histories.

The following is based on the literature in the References, particularly Refs 3, 4 and 7 and my engineering experience in eastern, western, and northern Canada, and overseas.  The literature emphasizes the process as it applies to professional people.  I have extended it to include other specialties.

I updated the blog October, 2017 to include a list of questions that should be answered when assessing the standard of care.  I’ve also noted the specific importance that is assigned to the practitioner’s application of judgement, diligence and the elements of care.  The questions have been taken from Chapter 3, The Standard of Care, in the Guidelines for Forensic Engineering Practice, 2012, Ref. 7 and from Refs 8 and 9.

I updated the blog again on October 30, 2020 to note that some areas where failures and accidents occur have not adopted the National Building Code of Canada.  The Code is a document relevant to assessing the standard of care for incidents in buildings as distinct from other civil engineering structures)

***

Often when a building or a civil engineering structure fails, or a component is defective in some way, the performance of the parties involved is called into question.  Did they exhibit the degree of care that a reasonable person should exercise?

Civil engineering structures can be anything built by man.  Also, anything in the natural environment that affects people, like floods and landslides.

Parties whose performance might be questioned

The parties involved could be anyone associated with:

• The exact technical cause of the failure or accident – the failure mechanism
• And/or the process cause that led to the failure or accident – the procedural cause of the failure or accident, the circumstances that led to the occurrence of the failure mechanism (Ref. 1)

For example, any of those parties in the process from the original owner of the building or civil engineering structure to the workers who maintained it.

And all those specialties and trades in between.  Like the architects, the design and construction engineers, construction and building trades’ workers, material and product manufacturers and suppliers, and product and equipment installers.

It’s also the case – questioning the performance of the parties involved – when an accident occurs causing property damage, personal injury, or death.

“Standard of care” questions

If that is the question – the performance of the people involved – there is often a need for an expert to do two things:

1. Determine and describe the skill possessed by normally competent practitioners involved in the technical cause of the failure and/or the process leading to the failure, and,
2. Develop an opinion – if requested by counsel – as to whether the defendant party conformed to that level of skill

These are “standard of care” questions.

1. The expert determines and describes the standard of care existing at the time the structure and/or its components were designed, built or maintained, or the accident occurred.  He or she determines what a reasonable person would do in similar circumstances.

2. Then the judicial system uses the description of the standard in assessing the actions of those associated with the structure or the accident scene.  The judicial system may consider an expert’s opinion on whether or not the parties involved deviated from the standard.

Experts are human

There are three problems with this approach of using an expert to determine the standard of care and whether or not the standard was breached:

1. Being human, experts are susceptible to applying personal standards.  They risk raising the standard of care by relying on their personal experience and practice.
2. Litigation is retrospective.  Usually an expert must determine what the standard of care was in the past, not what it is at present.  If he did not practice during the time period in question, he would have to determine the standard by interviewing others and reviewing documents.  Also, if there were a number of different procedures for getting something done at the time it would be necessary to determine the nature of each, and which one would have been seen as a standard.  Again by interviewing others and reviewing documents.  This is difficult and time consuming and involves a lot of e-mail, telephone, document, and leg work.
3. There are unique services, and some quite ordinary, for which no standard exists.

Experts retained to determine the standard of care must solve these problems.

Steps in determining the standard of care

Although a protocol for answering the two “standard of care” questions above in every case does not exist, the following steps will at least assist the expert.

They will also assist counsel and the judicial system acquire some understanding of the comprehensive nature of the process.  Also the technical issues involved in determining the standard of care.

Such a determination can be quite easy and straightforward in some cases, and quite difficult in others.  This affects costs as might be expected.  This is illustrated by two case histories described below.

I developed the stepped process – by extending the one in Ref. 4 – to include workers in the various supply industries, the building trades, and maintenance, in addition to the professions.  I found in researching the standard of care that much of the material concerned the performance of people in the professions.  However, there are circumstances when the performance of people in other fields of endeavour is of interest.

Before the process begins, counsel will need to advise when the building, civil engineering structure, and/or component was built.  He may also want to ask the expert for an opinion on whether or not the performance of those involved conformed to the standard of care:

Steps in the process

1. Establish the time period involved.
2. If there is reason to believe the standard is locality-specific, determine the applicable geographic locality.
3. Determine the circumstances that relate to the failure or accident.
4. Determine the technical cause of the failure or accident – the failure mechanism.
5. Determine the process in developing the structure or component involved in the failure or accident – the procedural cause.
6. Identify the professions, industries, and/or trades involved in the process and if they are well defined and understood as such.
7. Do these things by interviewing a number of representatives in the different fields of practice.  If there is variance, speak with more until you are satisfied you know the average. (Ref. 5)
8. Review the contract, or any other documents that define the party’s scope of work and any limitations on their services.
9. Perform a literature search to determine if the standard of care was documented in publications, manuals and guidelines, regulations, and/or codes.  This literature should be known to representatives and workers in the professions, industries, or trades associated with the failure or accident.
10. If the failure or accident occurred in a building, determine if the Building Code of Canada was in force at the time of the incident.
11. Interview a number of professional, industrial, product, and trade representatives to determine a consensus standard of care.  If there is variance, speak with more until you are satisfied you know the average.
12. Compare the consensus standard, as modified by contract, circumstances, or other justifications, with the questioned performance during design, construction, and/or maintenance of the building, civil engineering structure, or component.

This stepped process is quite comprehensive.  If followed it will assist the expert come to a clear understanding of the standard of care for a particular set of circumstances and enable the expert to describe it – answer the first of the two “standard of care” questions above.

It will also enable the expert to formulate an opinion as to whether or not the actions of the parties associated with the failure or accident conformed to the standard of care at the time – the second question.

Questions that should be answered in a stepped process for determining the standard of care

In going through a stepped process like the above to determine the standard of care the expert should make certain he or she answers the following questions.  These are as published almost verbatim in Guidelines for Forensic Engineering Practice (Ref. 7).  In a sense this is basically a stepped process separate from my own taken from the Guidelines:

• Does the expert have the degree of learning and skill ordinarily possessed by reputable professionals or workers, practicing or working in the same or similar locality, and under similar circumstances?
• Did the expert use the care and skill ordinarily used in like cases by reputable members of his or her profession or work practicing or working in the same or similar locality under similar circumstances?
• Did the expert use reasonable diligence?
• Did the expert use his or her best judgement?
• Did the expert do all that in an effort to accomplish the purpose for which he or she was retained?

To answer these questions, the following must also be determined:

• Who are “reputable professionals or workers”?
• What are “same or similar” localities and circumstances?
• What is “skill”?
• What is “care”?
• What are “like cases”?
• What learning and skill are “ordinarily possessed”?
• What care and skill is “ordinarily used”?
• What is “reasonable diligence”?
• What is “judgement”?
• What is the expert’s “best judgement”?
• What was the purpose for which the expert was retained?

“The standard of care is an assessment of the quality of care exercised by a practitioner, with specific importance assigned to the expert’s application of judgement, diligence, and the following five elements of the ethic of care, all of which are pertinent in engineering.”: (Refs 7, 8 and 9)

• Attentiveness: Caring about; noticing the need to care, or recognizing the need of others.
• Responsibility: Taking care; having more than an obligation, but a responsibility arising in part from one’s position or knowledge.
• Competency: Care giving; having the ability to carry out the caring act effectively and correctly.
• Responsiveness: Care receiving; being receptive to care, being aware of the care receiver’s perceptions.
• Integrity: Knowledge on the part of the caregiver of the situations, needs, and competencies of all the parties to the care interaction, including an assessment of needs in a social and political, as well as personal, context. (Refs 7, 8 and 9)

Workers in general, quite apart from those in the professions, must be assessed on their application of judgement, diligence and the five elements of the ethic of care.

The cost of the process

The cost of determining the standard of care can vary considerably.  It depends on:

1. The time period
2. The location of the failure or accident
3. The specialty, trade or profession of the person whose performance is questioned
4. The number of documents to research
5. The number of persons to interview
6. Whether or not there is a well-defined process guiding development of the building or civil engineering structure, and it’s components, or associated with the elements in an accident
7. Identifying the relevant parties in a poorly-defined process and how they are connected
8. The existence of relevant codes, industry standards, and guidelines

The following two cases illustrate how cost and difficulty can vary:

1. Large, complex structure but easy and inexpensive assessment of the standard of care:

I assessed the standard for the catastrophic failure of a soil-steel bridge – a very large, corrugated steel culvert – that permanently disabled a woman.

The assessment was easy and inexpensive because the design and construction process was well defined.  There were only two parties to interview: (1) The one design firm working in the area at the time and (2) The culvert manufacturer.

The assessment of the standard of care was easy even though it was a large, complex structure, the failure occurred about 10 years prior to my assessment, and the soil-steel bridge was designed and constructed about 35 years previously.

2. Small, simple component but difficult and expensive assessment:

Another assessment for a simple accident was difficult and expensive.  This was because the industry and the process associated with development of the small component of the structure involved – a floor – was poorly defined and made up of 11 parties, with many persons to interview.

The relationship between the parties, and who was responsible for what, was not well defined.  It was expensive even though a simple component was involved and the accident occurred quite recently.

References

1. Nicastro, P.E. David E., ed., Failure Mechanisms in Building Construction, American Society of Civil Engineers (ASCE) 1997
2. Black’s Law Dictionary, 4^th pocket edition 2011
3. Kardon, J. B. 2000, 2010 Chapter 7, Standard of Care in Forensic Structural Engineering Handbook, R. T. Ratay, Editor-in-Chief, McGraw-Hill, New York.
4. Thompson, D. E. and Ashcraft, H. W. 2000, 2010 Chapter 9 Page 9.17 in Forensic Structural Engineering Handbook R. T.  Ratay, Editor-in-Chief, McGraw-Hill, New York.
5. Association of Soil and Foundation Engineers (ASFE) 1985 Expert: A Guide to Forensic Engineering and Service as an Expert Witness
6. Mangraviti, Jr., James J., Babitsky, Steven, and Donovan, Nadine Nasser, How to Write an Expert Witness Report, SEAK, Inc., Falmouth, MA 2014
7. Kardon, Joshua B., Editor, 2012 Chapter 3, The Standard of Care in American Society of Civil Engineers, Reston, Virginia
8. Tronto, J. C. (1993), Moral Boundaries: A Political Argument for an Ethic of Care, Routeledge, New York.
9. Kardon, J. B. (2005), The Concept of “Care” in Engineering.  American Society of Civil Engineers, Journal of Performance of Constructed Facilities, Vol. 19, No. 3, pp. 256-260.

Posted by Eric E. Jorden, M.Sc., P.Eng. Consulting Professional Engineer, Forensic Engineer, Geotechnology Ltd., Halifax, Nova Scotia, Canada, June 28, 2014. Updated October 30, 2020 ejorden@eastlink.ca  

It’s not very glamourous – and it does cost money, but if a structure is not maintained as designed and constructed it won’t perform as intended.  Poor maintenance can actually be the cause of a building or civil engineering structure failing, or an accident occurring.

Examples

For example, I investigated a slip and fall accident on a stair landing at a retail outlet several years ago.  Residual detergent from cleaning the landing was a factor in causing a man to slip and fall and injure himself.  The detergent reduced the skid resistance of the floor material covering the landing from adequate to inadequate.

Another example was the classic failure of a soil-steel bridge – a very large, corrugated steel culvert, carrying a road over a stream.  My forensic investigation found that the water corroded the hunches of the culvert causing it to collapse injuring a car driver.  Corrosion of the hunches – a critical part of a soil-steel bridge, is a classic fact of life for these types of bridges.  Better design, and regular inspection and maintenance would have prevented the failure.

To be fair, I’ve not seen reference to the need for proper maintenance on very many design and construction drawings over the years, if any.

Maintenance part of design and construction

Yet proper inspection and maintenance is part of the design and construction process.  I noted this in a blog a couple of years ago on the failure of the Elliot Lake parking garage (Ref. 1)

So, how’s an owner to know?  It seems, at the very least, that if you observe deterioration in your structure then you know you no longer have what was originally designed and built.  And no longer what users of the structure understand it to be – as serviceable and safe as originally intended.

Coming along every now and then and ‘restoring’ a structure doesn’t count because what you’re restoring is the effects of poor or no maintenance.  Regular maintenance is what counts if a structure is to reach its design life.  This is the length of time a structure is designed to be serviceable.  It is quite an important concept in engineering design.

Mysterious report on parking garage maintenance

I was reminded of the importance of proper maintenance when I read an item on the enquiry of the Elliot Lake parking garage failure in a recent MacLean’s magazine. (Ref. 2)  There was frequent reference to maintenance in the two page item.

I also see an item in today’s Chronicle Herald, Halifax, about the maintenance needs of the 4,300 bridges in Nova Scotia – and the fact the money may not be there for all the maintenance necessary (Ref. 3).  Or some of the money that is available might perhaps be better spent on other projects.  The item noted that maintenance must be done on some bridges just to get them in fair or good condition.  Does that mean some bridges in Nova Scotia are in poor condition?

The MacLean’s article was reporting on the mysterious appearance at the enquiry of a report from the Ontario Ministry of Housing, circa 1988, written by an expert advisory panel on the “Deterioration, repair, and maintenance of parking garages”.

The new-found report wasn’t the first to sound the alarm about “rotting parking garages”.  CMHC (the Canada Mortgage and Housing Cooperation) issued three research reports in the 1980s about the deterioration in parking garages.

The answer

Regular inspection and repair – maintenance when carried out on a regular basis, was the answer running through the reports.

This was also the answer to preventing the failure of the soil-steel bridge.  Simply walking through the culvert at low water, noting any corrosion, and fixing it.  I did this at several intact soil-steel bridges in eastern Canada – simply walked through them, during my investigation of the failure.

The need for cleaning a soapy residue from a stair landing at a retail outlet is not very glamourous maintenance work but simple to do.

References

1. Cause of the roof collapse at Elliot Lake, posted July 10, 2012 http://www.ericjorden.com/blog/2012/07/10/cause-of-the-roof-collapse-at-elliot-lake/
2. Elliot Lake: Warning signs, long forgotten, MacLean’s Magazine, June 9, 2014
3. Chronicle Herald, page A5, June 12, 2014