Johnson Street Bridge lawsuits

How time flies! I first covered Victoria, BC's Johnson Street Bridge some nine years ago, most recently writing about it again in January 2018.

Image courtesy Thedarkempire / Wikipedia

The project was initially controversial for the proposal to replace a 1924 historic heel-trunnion bascule bridge with a modern design. The new design was devised by MMM engineers with Wilkinson Eyre architects, and is a rolling bascule bridge, the largest such structure in Canada. Opposition from heritage groups was eventually defeated and the new bridge was completed and opened to traffic on 1st March 2018.

When I last reported, it was to discuss a dispute between contractor PCL, their client the City of Victoria, and the client's designers MMM. Wilkinson Eyre appeared to have long left the scene. There were also some really quite odd issues with the bridge's steel detailing.

The bridge has been back in the news again due to further legal disputes. These came to light late last year, with PCL filing a lawsuit against Victoria, MMM and design subconsultant Hardesty and Hanover. PCL have alleged that the designers provided a design which was late, incomplete, and contained errors; that the design was unreasonably changed; and they did not receive payments they were entitled to.

Some readers may recall that the contract was primarily traditional in nature, with the client responsible for providing the design, and the contractor building it. An odd feature of the procurement was that the contractor was obliged to value-engineer the client's design (PCL initially employed Hardesty and Hanover to help with this task).

Image courtesy Michal Klajban /Wikipedia

A key problem which seems to have haunted the project throughout its history is that the client's design was incomplete at the time that PCL tendered for the project, which is not normal practice in this kind of contractual arrangement. The contract setup is normally called "traditional" in the UK, or "design-bid-build" in North America, and the latter name indicates that the process is expected to be sequential, with the design complete before bids to build it are invited.

Local journalists suggest that PCL has merely lodged the lawsuit as a placeholder, a negotiating tool with the end aim of walking away from the project without any further liability on either side. This is based on a similar legal manoeuvre that took place in 2015/16.

A report in Focus on Victoria discusses the dispute but also draws attention to the general quality of the completed bridge. According to this report, some steelwork joints were sealed not by welding, but using a sealant material, which is already falling out. More interestingly, the bridge as-built is compared by Focus to the original design images from Wilkinson Eyre, such as the example below.

In the original design, large "ears" containing the bridge counterweights sit alongside the running rails on which the bridge rotates. However, both elements are blended smoothly together to give an organic appearance. With hindsight, it seems fairly clear that those flowing curves would be at best expensive and at worst impossible to fabricate, and likely to fall victim to the promoter's desire for value engineering.

Image courtesy Focus on Victoria

This picture shows what it really looks like, which is quite horrendous. There seems to be have been little thought about how to deliver a smooth curve in the steelwork, or even how to give the impression of one.

There's no manipulation here, either. The second image below shows just how disjointed the main steelwork trusses and counterweight ears actually are, with a physical gap between them on the outside face. To me, it looks quite bizarre.

Image courtesy johnsonstreetbridge.org

There are plenty of images on Google Streetview which show the issues as well.

Make no mistake: this is a remarkable bridge, with an interesting, exciting design. It's unfortunate that nobody was retained on the project with a brief to maintain the quality of the original design vision, and that the procurement process failed to find an acceptable balance between cost-cutting and quality.

Anyone who has worked on a complex landmark bridge project will know it can sometimes be a real battle to ensure an original idea isn't disfigured through messy compromise. Unless the client's commitment is there, it's difficult to resist negative changes. Even with a strong and imaginative client, success comes through all the team members pulling in the same direction, rather than being incentivised to do the opposite.

Johnson Street Bridge shenanigans

I can only scratch the surface of this exceptionally complex and sorry saga. Long-time readers may recall that I wrote about the Johnson Street Bridge project in Victoria, Canada, back in October and November 2009. I haven't really followed it in any detail since then, but I've been missing out on a fascinating story.

Back in 2009, the controversy was over Victoria's decision to replace a highly historic Strauss heel trunnion bascule bridge, a rare and complex structure (pictured, courtesy Cacophony via Wikipedia). In April 2009, the city had identified that the bridge was in poor condition and vulnerable to potential collapse in a seismic event. They commissioned engineers MMM and architect Wilkinson Eyre to develop options for a replacement span. An unusual and very interesting design was selected, a $63m rolling bascule bridge with a ring girder which rotates about its centre point (visualisation from WEA shown below).

Controversy centred on whether the new bridge was actually necessary, or whether the historic structure could have been refurbished rather than lost. There was plenty of discussion, and the debate was well publicised and well informed.

Things have moved on considerably. The span replacement project has continued, with PCL appointed as contractor and Hardesty and Hanover added to the design team. The structure is currently on site, due for completion in March. The budget for the project is now reported to be $105m.

Before you read any further, you may wish to find a comfortable chair, and pour a very large glass of whisky. Or two.

The people at johnsonstreetbridge.org were key in opposing the original intention for a bridge replacement, and have since kept a close eye on the project. They have links to a whole series of key documents which describe the scheme's often shambolic progress, which taken together make for very painful reading.

A particular classic is MMM's letter to the City of Victoria in May 2014. MMM were (and still are) appointed as Victoria's bridge design consultant; this is not a design-and-build project. PCL had a peculiar contract which covers construction but which obliges them to propose value engineering ideas with a view to reducing the cost of the project (clearly, this strategy has been a big fat failure!) Despite this glorious aspiration, PCL had written to Victoria in March 2014 requesting both an extension of time and an increase in their payment for the works. They argued that it was impossible to stay within their original price, and that they were entitled to more.

MMM's letter advised Victoria on whether to accept PCL's claim. It cannot be considered in any respect objective, as MMM were also defending themselves against a series of faults alleged by PCL. Read all 30 pages of it with a very large pinch of salt. However, it's a frankly terrifying read: an appalling saga of poor performance, buck-passing, and what must be one of the worst procurement arrangements I've ever seen.

I can't bear to give even the edited highlights of it here: go and read it (only if you really did pour that big glass of whisky) to see how this project was spiralling rapidly downhill. The real root of the problems is never mentioned, however, which is the absurdity of the procurement arrangement.

MMM had prepared a reference design for the City, although this was only quite preliminary in scope at the time when PCL were appointed (on what was supposedly a lump-sum contract). PCL were obliged to develop a value-engineered design as part of their bid, and appointed Hardesty and Hanover to assist with this. This was also not undertaken to any great level of detail. Despite this, PCL were obliged to stick to their agreed lump-sum, while Victoria and MMM retained full responsibility for the detailed design.

Yes, read that again, and weep if you wish. PCL could not properly control the design (and hence the extent of their construction work), yet were held to a fixed price. Indeed, PCL's designers, Hardesty and Hanover, were then novated across to join MMM's team in developing the detailed design. I don't think I've ever heard of such an arrangement before - the more obvious setup would have been to novate MMM to PCL so that the contractor could control the design-and-build process as an integrated exercise in order to mitigate their risks. This would at least have given Victoria complete clarity as to where any further problems lay. The whole arrangement is utterly bizarre.

Beginning to recognise that the project was in serious difficulty, Victoria appointed independent consultant Jonathan Huggett to report on what was going wrong, and recommend how it should be put right. His report was issued in July 2014, and sidesteps the obviously flawed contractual arrangements but highlights a complete lack of project leadership, the complete lack of collaborative behaviours, failure to properly identify and address key risks, and lack of independent dispute resolution, amongst other problems.

Huggett's report was clearly taken quickly to heart by the City of Victoria - even before he had finished writing it, he had already been appointed to take charge of the project going forward.

Somewhere in all this, it's worth noting that Wilkinson Eyre's original design has been substantially watered down in the ongoing effort to contain the ever-escalating costs. We can only guess how much higher the project budget would now be if the original design was still being built!

There are a few more reports worth reading if you poured a second glass of whisky, not just one.

Online news site Focus on Victoria has been a dogged pursuer of the project's difficulties. An article earlier this year on issues with the bridge's fendering design is a splendid example of how easily the project seems to have blundered into difficulty.

The latest reports from Focus cover issues with the bridge's steel fabrication. They highlight the discovery of a problem with the steelwork, which appears to have been covered over with a truly awful looking bolted plate, a real bodge if ever you see one (photos are from Focus, with permission). The steel ring girders had to be cut open for repair work, although the reason has not been made public in any detail. The contractor's QA firm reportedly found a "design flaw" while steel was under fabrication in China.

This doesn't really make sense: QA firms are not there to validate design, they are there to ensure compliance with the design during construction. Indeed, Focus's lengthy article may well be making a mountain out of a molehill, suggesting a cover-up and conspiracy to the extent of malfeasance. It's difficult to judge the seriousness of the issue without further information being made available. However, Focus is quite write to criticise the detail. It's clear from the photographs that nothing this awful should be considered acceptable as part of the finished structure.

Like a dog with a bone, Focus won't let this one go, returning with a second article wondering quite why the (presumably exasperated) City Council won't make public all the details. What have they got to hide? Perhaps on a project so bedevilled with disaster they simply lack the energy for further exposure. Who could blame them? On the other hand, Victoria has been exhaustively open about what else it releases, down even to copies of supplier invoices.

This is a complex and innovative bridge, and it's hard not to think that further problems will occur before the project will be complete. Some of that is inevitable with such a bespoke, pioneering design. I certainly wouldn't bet against mechanical problems during the commissioning stage. Teething problems are, however, normal, and I hope that any further press coverage is balanced rather than sensational.

If all goes well, in a few months time we can look forward to seeing the completed bridge, and comparing it against the original vision. Hopefully it will be something that everyone involved can be proud of. However, the tale of woe that has bedevilled the project from the outset will continue to offer many lessons to be learned for others involved in bridge procurement, long after the dust eventually settles.

Canadian Bridges: 8. Port Mann Bridge, Vancouver

This was the final bridge I visited on my September trip to Vancouver. The Port Mann Bridge was completed in 2012 as a 10-lane replacement for a steel arch highway bridge spanning the Fraser River. It is the centrepiece of a much longer highway improvement project.

With a 470m main span it is reportedly the second longest cable-stayed bridge span in North America (behind Mexico's Baluarte Bridge), but it doesn't even dent the top 50 worldwide. It was also briefly the world's widest long-span bridge (67m wide), before being overtaken by the San Francisco Oakland Bay Bridge (79m wide) in 2013.

I can't confess to being a great admirer of the new cable-stayed bridge span.

The choice of single pylons sitting in between twin deck sections seems at first sight to be aesthetically wise (cf. Stonecutters Bridge, Millau Viaduct, Queensferry Crossing). However, due to the bridge's tremendous width, four planes of cable stays are required, leading to quite a dense, confused appearance.

This also directly leads to the over-sized upper pylon sections, which are as large as they are solely to have enough space to accommodate the huge number of cable anchorages. Nonetheless, it is reported that this arrangement is less expensive than the alternative A-frame, H-portal or multiple mast pylons, and cost was the primary driver for the whole project.

Cable-stayed bridges often suffer from an imbalance between tower profile above and below deck, as out-of-balance longitudinal thrusts in the deck are restrained at the towers. The Port Mann Bridge has avoided that particular peril, with well-proportioned lower tower sections. T-shaped crossheads support not only the deck, but also anchor stability cables for the upper towers.

The span arrangement appears odd, but is rational. The south pylon sits well on land, while the north is in the middle of the river. The cause for this is the spacing of various obstacles: a railway yard requiring a significant span at the south end; a requirement for the adjacent tower to be on dry land to prevent any risk of scour to the riverbank protecting the same railway yard; and the position of the main and secondary navigational channels in the river.

The bridge is well known for the troubles it developed shortly after opening, with ice forming on the main cables and falling as "ice bombs" onto terrified car drivers below. This has since been treated with a mixture of hydrophobic coatings and ice-removal collars which can be slipped up and down the cables. I'm only guessing, but perhaps the controversy explains why the main bridge designer TY Lin doesn't feature the bridge on their website project gallery.

My main interest in sharing this bridge, however, is not for the main span but for the northern approach viaduct. I believe this was designed by Californian firm IBT (now part of Systra), and it's a classic post-tensioned box girder viaduct, a form in which IBT have considerable expertise. IBT are certainly happy to have the project on their website.

The arrangement is highly economical and also very beautiful. Three prestressed box girders sit on simple rectangular concrete piers. The girders are trapezoidal in cross-section, with the bottom face lightly arched. The bottom face therefore varies in width, adding interest to what is otherwise very plain.

It doesn't seem in any way unusual, but I think the detailing is excellent, with only a few lighting column and sign supports appearing as an afterthought. The concrete construction is also of excellent quality, and it's a tribute to how attractive a simple and economical engineer-led solution can be when it's delivered with such splendid clarity.

Further information:

• Google maps
• Wikipedia
• Structurae
• Design Basis for the New Port Mann Bridge over the Fraser River (Goodyear, Structural Engineering International, 2017) 
• System Failure Case Study – Ice Falling from Port Mann Bridge Cables (Eiche, SysEne Blog, 2016)

Canadian Bridges: 7. Sky Pilot Suspension Bridge, Squamish

From Vancouver, I travelled north on the Sea to Sky Highway towards Whistler. Along the way, near Squamish, I stopped at the Sea to Sky Gondola, which takes visitors from the highway 885m up into the mountains, admiring fantastic views along the way and again at the top.

There are various hiking trails for visitors to enjoy, but you don't want to hear about the beautiful natural scenery or the facilities for daytrippers. You want to hear about the Sky Pilot Suspension Bridge.

The name comes from nearby Sky Pilot Mountain, which is clearly visible from the Gondola station and adjacent bridge - you can see it in the background of some of my photos.

The bridge was designed and built by ISL Engineering, working with Macdonald and Lawrence Timber Framing. It is an 86m suspended span anchored into granite mountainsides at both ends, and crossing a valley which spills downhill immediately beside the upper Gondola platform.

The basic structural design of simple suspended bridges like this is not especially complex: the force in the cable is readily derived from the load (self-weight, pedestrians, and/or snow in this instance), the span, and the cable sag. However, the Sky Pilot Suspension Bridge is very well executed and has a number of interesting features.

Compare it to Vancouver's Capilano Suspension Bridge. The Capilano span relies entirely on main cables at handrail level, from which everything else is hung. It is reasonably heavy, yet prone to considerable movement.

The Sky Pilot bridge has a significantly lighter appearance, particularly in the walkway floor, and would be prone to unacceptable movement if it were not for the incorporation of reverse catenary cables, curving downwards to either side of the bridge. These significantly stiffen the span both vertically and horizontally, and make for a much more comfortable crossing.

The counter-curved cables are attached to edge cables at walkway level, and these cables also appear to be tensioned, being connected to the same supports as the handrail cables.

The bridge supports are interesting, short steel posts at the end of the deck, with the handrail and walkway cables attached top and bottom. These posts are then each attached to a single rod about a quarter to a third of the way up, which carries the full tension force from the bridge into the ground. It looks like these posts are having to work very hard in order to make sure the tension loads are carried away below walkway level.

The detailing of the bridge is excellent. There is nothing extraneous, everything is purely functional, but very crisply assembled. The connections of the vertical hanger wires, the horizontal parapet wires, the arrangement of the cross-members below the wooden deck - it has a very Swiss or German appearance, if that's not too much of a stereotype. I don't think I found anything on the bridge to criticise.

It would be interesting to compare this span against other lightweight modern suspension footbridges - feel free to comment on this post if you've visited other comparable structures.

Further information:

• Google maps
• Official website
• 5 awesome suspension bridges near Vancouver, British Columbia

Canadian Bridges: 6. Treetop Walkway, Capilano, Vancouver

The third attraction I visited at Capilano Suspension Bridge Park, of relevance here, is the "Treetops Adventure", an elevated walkway formed of seven suspension bridges slung between eight 250-year old Douglas Fir trees.

It was opened in 2004, and allows visitors to experience the forest from up to 33m above ground level.

The structures were designed by McElhanney Consulting Services to have as little permanent impact on the trees as possible. Platforms around the tree trunks, and the bridge spans themselves, are supported from collars, connected without any nails or bolts. These act only in compression, tightened so that friction is sufficient to hold them in place. Out of balance forces on trees carried by braided polyester guy ropes.

The collars are adjustable and moveable, so that they can accommodate continuous growth of the trees, and are regularly inspected by the engineers to see whether adjustments are necessary. The pressure on the tree bark is reported to be about 20 psi, which in metric is a piffling 0.14 N/mm².

Unlike the neighbouring Capilano Suspension Bridge, the support cables are below the deck, rather than being at handrail level. This is necessary to allow visitors to exit each span and walk around the tree trunks without having to climb above bridge handrail level. It also offers the benefit of giving unimpeded views from each span, although these are marred by chunky brown-painted handrail posts.

As you'd expect, there's a fair degree of movement on each span as you walk across it, but not to an extent which will un-nerve many visitors.

I can't say I entirely admire the appearance of this walkway, which is clunky, with way too much of that brown-painted metalwork. However, I think the way it has been engineered is highly admirable.

There can't be many sites blessed with such mighty trees that they can support a structure in this way, but that's just one reason why this one is worth visiting.

Further information:

• Google maps
• Official website
• Capilano Treetop Adventures - Forest Canopy Walkway Bridges (Williams and LaRose, Annual Conference of the Transportation Association of Canada, 2006)

Canadian Bridges: 5. Cliffwalk, Capilano, Vancouver

There are three main attractions at the Capilano Suspension Bridge Park. The Cliffwalk can be found a short distance to one side of the main bridge.

The Cliffwalk was opened in 2011. It was designed and built by Morrison Hershfield. The walkway is supported from the upper section of a 90m tall granite cliff face. It is some 213m long, with a 30m long cable-supported section, but it is claimed to have an environmental footprint of just 11 square metres. This is the amount of contact made with the cliff-face, which was carefully surveyed to identify suitable locations of rock anchors to be installed.

Over its length the cliff walk descends around 9m, before rising nearly twice as much, with a series of staircases. The main walkway is 0.5m wide at floor level, and 0.8m between handrails. Parapets are 1.2m high, which I found adequately reassuring. The parapet infill is a stainless steel mesh.

The narrow walkway is generally suitable only for passage single file, which requires a degree of patience when the crowds are visiting, but there are balconies and platforms at intervals to allow people to pass or stand for longer to admire the views.

The structure generally comprises galvanised steel, with stainless steel handrails. The floor is timber except for a couple of platforms with glass and grille flooring, deliberately inserted to make the whole experience more of a "thrill".

The whole assembly sits typically 3m off the cliff-face, intended to minimise the risk of damage due to rockfall.

The entire structure is reported to be able to carry 45 tonnes of load, which equates to a live loading of 4kPa. This seems ample given the restricted space provided.

Selected parts of the bridge were fully load tested to this level using water barrels, before the bridge was opened to the public. There's no mention of any analysis or testing for vibration in the paper published regarding the bridge's design and construction, but I didn't detect any significant movement.

The Capilano Cliffwalk is a well-designed and built structure, which strikes a good balance between a sense of fear and a sense of security. The detailing is pragmatic yet attractive, and it has certainly enhanced the value to be gained from a visit to the Capilano Suspension Bridge Park.

Further information:

• Google maps
• Official website
• Design and Construction of the Capilano Cliffwalk (LaRose, Loptson, Wyllie and Masterson, Annual Conference of the Transporation Association of Canada, 2011)
• 2012 Canadian Consulting Engineering Awards Submission

Canadian Bridges: 4. Capilano Suspension Bridge, Vancouver

I mentioned previously that Lion's Gate Bridge is Vancouver's best known bridge, but the Capilano Suspension Bridge must run it close. Spanning 137m long, 70m above the Capilano River, it's also one of Vancouver's major tourist attractions.

Scottish civil engineer George Grant MacKay bought 6000 acres of wilderness from the Crown for 1 dollar per acre. In 1889 he worked with local First Nations people to connect both halves of his property with a suspension bridge. An information board at the site states his assistants to have been August Jack Khatsahlano and his brother Willie, but Wikipedia indicates August Jack to have been aged only 12 at the time of bridge construction. The new span was built from cedar wood and hemp rope, secured to trees on one side of the deep gorge, and to a buried tree on the other.

Engineer William Farrell replaced the original span with a bridge using wire cables in 1903. It was always a tourist destination, although in the early part of its life, it was a considerable trip from the main part of Vancouver via a ferry and a six-mile hike. Increasing visitor numbers meant that additional support cables were added in 1914.

The bridge that can be seen today is the result of a complete replacement in 1956, on the instruction of the owner at that time, Douglas McRae Mitchell. It was reportedly designed by Art Williams, the engineer, to carry 1,333 persons. Steel cables were anchored into 13 tons of concrete at each end, which I have to say doesn't sound like very much, and an information board at the bridge notes that the current anchors are 24 tons, which is a little more reassuring.

Today the entire site is a tourist mecca, with plenty to do beyond just walking across the bridge. It crosses a scenic canyon where reportedly bears and eagles can sometimes be seen, although I was not so lucky. It's surrounded on all sides by huge cedar and fir trees, including several very impressive forest giants.

The structural form is a simple suspended span, with the main cables secured into anchorages hidden out of sight below timber platforms. Short hanger cables connect to timber cross-beams which carry the walkway.

The views from the bridge are spectacular. It doesn't feel unsafe under moderate loading as seen in the photos, but it does sway quite noticeably. I've provided some videos of the sway below, seen from different angles.

I found it awkward to walk on, but not to the extent of feeling unsafe, although clearly anyone with vertigo or balance problems may not be able to cross the bridge (the whole tourist attraction is best entirely avoided in this circumstance!)

The Capilano bridge is small beer when compared to other long-span pedestrian bridges, including the new record-breaker near Zermatt, but I found it very impressive.

The suspension bridge park also features a treetop walkway, and a suspended cliffwalk, both of which I'll cover in my next two posts. The cliffwalk can be seen in the first photograph below.

  

Further information:

• Google maps
• Wikipedia
• Structurae
• Capilano Suspension Bridge Park
• Capilano Suspension Bridge Park (McQuarrie, 2017)

Canadian Bridges: 3. Granville Bridge, Vancouver

Granville Bridge is the next bridge east along False Creek in Vancouver after the Burrard Street Bridge.

Completed in 1954, the 1.1 km long bridge carries eight lanes of highway traffic and two footways between Downtown Vancouver and Granville Island (and beyond).

It is the third bridge on this site, with a timber trestle bridge erected in 1889, replaced by a steel truss bridge in 1909. Both structures incorporated swing spans.

The current bridge was designed by engineer John Robert Grant to sit at a significantly higher level than its predecessors, eliminating the opening span and thus accommodating much higher traffic levels. Pressure for change had no doubt been partially addressed when the Burrard Street Bridge was completed in 1932 (also designed by Grant).

Granville Street Bridge lacks the architectural attention that was devoted to its Burrard street neighbour. The main span is a conventional steel cantilever truss, notable only for the main span truss being significantly less deep than the approach span trusses, which didn't have to respect the same shipping clearance. This looks more than a little odd, but it's understandable given the need to reduce the overall length of the structure. The side spans are seen less clearly, with a background of buildings, so I imagine the odd relationship simply isn't apparent to any casual observer.

Although the design is pretty much entirely engineering-led, it's not unattractive or inappropriate to its setting. It is rational, orderly and from most viewpoints, uncomplicated.

Proposals have recently been made to add an elevator where the bridge passes above Granville Island.

Further information:

• Google maps
• Wikipedia
• Structurae
• 1954 film about the bridge construction