Documents recently obtained by FOI show the City of Victoria was warned by engineers of two of the three companies bidding on the Johnson Street Bridge project that the floating-ring design was too risky to build. The City went ahead anyway.
THE GOOD NEWS IS that the City of Victoria finally released the three November 2012 bid proposals for the new bridge contract. Those proposals were the only chance for City councillors and interested citizens to hear what experienced bridge engineers thought about the design Wilkinson Eyre and MMM Group dreamed up in a hurry back in 2009. The bad news is that whatever the engineers said probably wasn’t heard by City councillors and is now irrelevant. There’s no going back—the bridge is being fabricated in China and steel support pilings drilled into the harbour as you read this. Focus requested these documents in November 2012. They were released to us by the City last month. The ugly news is what the engineers said.
The three companies chosen to submit bids—PCL Constructors Westcoast, Kiewit Infrastructure, and Walsh Construction—were required to provide an “Indicative Design Review” as part of their bids. Each of the companies was paid $50,000 for their participation. The “Indicative Design” was the final version of the design the City contracted MMM Group to develop with Wilkinson Eyre. Below is a drawing of the most contentious element of that design—the lifting mechanism.
MMM Group's "Indicative Design"
Providing proof that nice guys finish first, PCL didn’t have much criticism to dish out. Instead, they offered up a reworked MMM design that Victoria is likely going to regret in 30 or so years. Why? Because that’s the design life for critical “subject to wear” parts of the lifting mechanism that PCL had to incorporate in order to meet the City’s “affordability ceiling.” And for reasons that I’ll tell you about towards the end of this story, replacing those critical parts may be impossible short of taking a cutting torch and a wrecking ball to the bridge.
The big story here is that Kiewit and Walsh both ditched the Indicative Design’s fundamental mechanical concept: the two big rings floating freely on supporting rollers. This was the first time engineers had been able to publicly voice their professional opinion about the design (engineers are constrained by their Code of Ethics from publicly commenting on the work of other engineers) and a rare opportunity for the public and their elected representatives to get independent reviews of MMM’s claim that it would be reliable and durable. Kiewit’s and Walsh’s critiques of MMM’s design contained several concerns that were addressed in PCL’s proposal, so in the summary below I am including only criticisms that PCL’s final design did not address.
As mentioned, the Kiewit and Walsh proposals both broadly rejected the heart of MMM’s Indicative Design, the mechanism used to raise and lower the movable section of the bridge. MMM’s design called for the lifting part of the bridge to be attached to two 50-foot-diameter rings, each of those supported by four large rollers. By rotating the 50-foot rings, the bridge could be raised or lowered.
Since 2009 the mechanical concept has gone through several iterations, indicating uncertainty. Project watchdog Ross Crockford, a director of johnsonstreetbridge.org, called the design “experimental,” in 2010, which brought this response from MMM’s Joost Meyboom: “...elements of the proposed mechanical system have been developed to be simple and robust. They are based on applications from heavy industry such as foundries where similar mechanical arrangements have been used for decades under conditions that are considerably more aggressive and demanding than anticipated at the Johnson Street Bridge.”
But in their bid proposal to the City Walsh’s engineers noted, “To the best of our knowledge, the only other application of this bridge type, also designed by Wilkinson Eyre, was built for the City of London’s Canary Wharf development. That bridge is significantly smaller than the proposed Johnson Street Bridge. Maintenance of the support rollers might be very difficult since the entire weight of the bridge rests on these supports. Should repair or replacement [of the rollers or their bearings] be necessary, jacking of the entire truss will be required to remove the load from these supports. The depth of the bridge pit will make shoring of the truss difficult and expensive and increase maintenance cost for this critical item.”
Kiewit said it had consulted with “a number of steel and machinery fabricators, who are experienced in movable bridge design and/or construction. All expressed the opinion that there were likely more cost effective mechanical concepts for a bascule bridge than the one used as the basis for the Indicative Design.” Kiewit said “unknowns and/or unexpected costs” of MMM’s “unconventional design” would “conflict with the City’s mandate to remain near or below the indicated Affordability Ceiling. In summary, Kiewit is of the view that the Indicative Design may represent a fundamentally high risk and expensive design approach.”
Kiewit’s engineers said their “comprehensive” review “resulted in the decision to propose a bascule concept based upon a more proven bridge type—the Strauss Bascule with under-deck counterweight. Joseph Strauss was a pioneer in bridge engineering who is best known as the Chief Engineer for design of the Golden Gate Bridge in San Francisco. Strauss was also responsible for many innovative design patents and design of several movable bridges, including the existing Johnson Street Bridge.” Kiewit provided detailed drawings of the mechanism they were proposing.
Kiewit's mechanical concept with span in open position
Besides the Indicative Design’s unproven lifting mechanism, Kiewit noted that the counterweight in the Indicative Design was attached to the truss rings in a way that “would load the truss ring eccentrically, which could distort the ring—a highly undesirable condition.” The Strauss mechanism, they said, would provide a fixed axis on which the bridge could rotate, eliminating the complex arrangement of rollers beneath the rings. Kiewit noted their mechanism would reduce “seismic challenges” as well.
Walsh, too, advised the City to use a mechanical design with proven reliability. They proposed to convert the design to a “rolling lift,” which, they said “continues to be used on numerous rolling lift bridges throughout the world.” Because “the drive system is a proven concept, it will meet the life expectancy requirements of the project and potentially lower overall maintenance costs over the life of the bridge.” Walsh did not include drawings of its proposed design.
There were other aspects of MMM’s design criticized by the companies.
Walsh provided the City with a sobering warning about the light-weight bridge deck specified for the bascule leaf: “The orthotropic deck will impose significant ongoing costs for maintenance of the roadway coating. It is expected that the deck will require recoating every five to ten years. In order to accomplish this, portions of the bridge will have to be closed, the deck sandblasted and new coating applied. We believe this will have significant long-term maintenance costs for the City.” Their solution? “An open grating deck with concrete-filled pathways for bicycles has a lower initial cost, easier erection, longer life...”
Kiewit worried the difference in widths of the pedestrian walkway and the multi-modal pathway would “destabilize the balance of the bridge in both the static and dynamic conditions.” The “overhanging walkways” were “unnecessarily complicated,” and “introduce the possibility of harmonic oscillation that could be very uncomfortable for pedestrians.” This is the vibrational phenomenon that troubled the Millenium Bridge in London which, after being opened for just three days, closed for two years while modifications were made. Kiewit’s solution was to widen the south side pedestrian walkway to match the north side and place both walkways at the level of the road deck, as in the existing bridge.
Walsh’s bid proposal totalled $91.6 million; PCL bid $63.4 million. Kiewit withheld its bid price from the record released to Focus. (UPDATE: The City of Victoria released Kiewit's bid amount in November 2014 in response to direction from OIPC following an FOI filed by Focus. Kiewit's bid proposal was $80.99 million.)
After receiving and considering the bid proposals from PCL, Kiewit and Walsh, an evaluation committee of City engineers—Peter Sparanese, Dwayne Kalynchuk and Ken Jarvela—delivered a report and made recommendations to a closed meeting of City councillors in November 2012. Since the meeting was closed, there’s no way for the public to know if councillors were made aware of the Walsh and Kiewit engineers’ warnings and concerns, or whether they were told that PCL’s proposal included a 30-year design life for the many parts of the bridge’s mechanical system subject to wear.
Councillor Lisa Helps told Focus that councillors had previously agreed to let City staff do the digging through the proposals; councillors were to confine themselves to voting on the evaluation committee’s recommendation.
Did this hands-off approach serve the public interest? The substance of the Kiewit and Walsh proposals, along with the maintenance liabilities inherent in PCL’s adaptation of MMM design, suggest MMM had spent millions of taxpayer dollars developing a bad design. If councillors—who hold office to represent the public interest—weren’t told the truth about the problems, whose interests were being served?
There were both private political and economic interests at stake that didn’t necessarily work well with the public interest.
The mayor and councillors who supported the bridge project from its inception would have lost political face in a public humiliation of the project.
But the bigger loser likely would have been MMM. Three days after the closed meeting at which City staff briefed councillors on the bid proposals, the City announced a new $9.1 million project management contract with MMM Group. That was on top of $2.1 million for project management and design services performed between 2009 and 2012.
If City engineering staff had provided councillors with as full an account of what the bid proposals contained as you have just read, would councillors have agreed to renew MMM’s contract?
Councillors could still vote to “rise and report” on what they were told at that meeting. In the meantime Focus has filed an FOI for the evaluation committee’s report and the minutes of that meeting. We will report on those when we get them.
From other FOI requests filed in the last few months, more information about the design of the bridge has emerged.
We have learned that no seismic assessment of the PCL design has been performed. Given the political promises to build a bridge able to withstand a magnitude 8.5 earthquake, the absence of even theoretical confirmation that the bascule leaf would indeed remain on its rollers in the so-called “Big One” is a surprising oversight. The ring truss isn’t physically attached to the substructure of the bridge in any way—it simply floats on the rollers—and the only thing keeping it from sliding off to one side or the other is a lip on the rollers about one inch high.
Engineering drawings obtained recently have revealed certain features of the bridge that could make it “iconic” in a way not intended by the councillors who pushed for a signature bridge. The bridge could also become an international symbol of poor planning, a miniature Fukushima.
This stems from the way in which the central design feature of MMM’s mechanical system—the rollers under the rings—have been reconfigured (again) by PCL’s engineering consultant Hardesty & Hanover. They initially proffered a support system that had 32 rollers under each ring instead of the four MMM envisioned. Now Hardesty & Hanover have changed their minds and believe 12 big support rollers for each ring is the magic combination. As you can see in the drawing below, to support all those big, heavy 42-inch-diameter rollers there is now a forest of machinery beneath the rings. This could be tough on future taxpayers: there appears to be no way of jacking the rings off the rollers to do necessary repairs like replacing the bearings; the space where jacks and shoring would go is filled with rollers and other unmovable machinery. The task that Walsh’s engineers warned would be “difficult and expensive” is now going to be even more difficult and more expensive. The wheels of progress grind on.
Hardesty & Hanover mechanical system as per final construction drawing
Another fundamental change Hardesty & Hanover made to MMM’s design was to change how the rollers contacted the rings. MMM’s design had the rings sitting directly on top of the rollers; they specified that a replaceable wear plate be attached to the rings. A simple, elegant idea. But MMM’s design required very precise—and expensive—fabrication tolerances for the rings. Hardesty & Hanover called them “impossibly tight...and impossible to maintain.” To get around that, and to stay within the City’s imposed affordability ceiling, Hardesty & Hanover came up with a truly bizarre cost-saving solution. Around the outside of each ring 11 U-shaped steel “support segments” will be attached. Each of these segments consist of about 85 separate pieces of steel that will be subject to rusting: lengths of crane rail, gear track, bolts, nuts and washers, flat metal plates, curved metal plates, etc, etc. Aesthetically, it will be messy. The segments will be arranged around one-half the outside circumference of the rings and—this is the truly strange why-is-this-happening-to-us? part—the strength to transfer the weight of the bridge to the rollers will be provided by epoxy grout pumped into the void between the segments and the rings. Not just a little epoxy grout, mind you, but iconic, mind-blowing amounts. Each ring will be swaddled in a semi-circular slab of epoxy grout that, if laid out flat on the ground, would be 12 inches deep, 55 inches wide (at its widest) and 80 feet long.
The critical elements that connect the rings to the support segments will be forever encased in that epoxy grout, un-inspectable and inaccessible for the life of the bridge. And, because epoxy grout and steel have different thermal qualities, the grout will become fractured and separate from the steel. Water will get between the grout and the metal parts and corrosion will occur. How much corrosion? Since the parts will be inaccessible, no one will ever know.
Has this technique ever been used on a bridge before? I posed that question to the professional engineer whose stamp appears on the construction drawings. He’s Sean Bluni, CEO of Hardesty & Hanover, working out of their New York City headquarters. I also asked Bluni how the bridge could be jacked to repair or replace subject-to-wear parts. Bluni said, “As we are contractually required to do, we will discuss your questions with the parties to whom we are providing service on this project.”
Most likely, this will require a closed council meeting.
David Broadland is the publisher of Focus Magazine.