Project Management Institute

Minnesota Department of Transportation, Minneapolis, Minnesota, USA




Interstate 35W bridge in Minneapolis, Minnesota, USA, collapsed into the Mississippi River on 1 August 2007, nearby security cameras captured every terrifying detail as the road lurched, buckled, then dropped dozens of cars and massive chunks of concrete into the churning waters below. Thirteen people died and 100 were injured in the rush-hour tragedy.

Last January, investigators for the U.S. National Transportation Safety Board traced the failure to flaws in the steel structures that held beams together on the 40-year-old bridge.

Peter Sanderson, project manager for Longmont, Colorado, USA-based Flatiron Constructors, now faces the difficult job of leading the team rebuilding the bridge. Adding to the pressure is the realization that every move would be subject to the close scrutiny of the public and the global transportation community.

“It's like working in a fish bowl,” jokes the British-born Mr. Sanderson.

His calm demeanor and Zen-like approach to chaos come from decades of experience in bridge building, although he says this project is unique for many reasons. Notably, because it's a major artery for commuters traveling into Minneapolis, the bridge needs to be completed fast. What would normally be a three-year project, Flatiron and project partner Manson Construction Co. are scheduled to complete in 437 days, with 24 December 2008 as the delivery date.

The tight deadline has made risk management all the more important.

“There is a tremendous amount riding on how safely and successfully we do our job,” Mr. Sanderson says. “The slightest problem could land us on page one of the newspaper.”


From left: Peter Sanderson, Longmont, Colorado, USA-based Flatiron Constructors and Jon Chiglo, Minnesota Department of Transportation

From left: Peter Sanderson, Longmont, Colorado, USA-based Flatiron Constructors and Jon Chiglo, Minnesota Department of Transportation


The team rebuilding a collapsed bridge works to meet a tight deadline and address heightened safety concerns—all under massive public scrutiny.


$234 million

Flatiron's winning bid to rebuild the bridge—$57 million over the lowest bid


Number of days scheduled for the bridge to be completed

$7 million

Bonus Flatiron could receive if it meets its 24 December deadline


Additional bonus Flatiron receives for every day it finishes early

Knowing this would be a highly scrutinized project, the Minnesota Department of Transportation (Mn/DOT) chose the most experienced contractor that bid on the project—even though Flatiron's $234 million bid came in $57 million above the lowest offer.

“In our scoring criteria, 50 percent of the emphasis was placed on experience, quality and safety,” says Jon Chiglo, Mn/DOT's project manager for the bridge project. “Flatiron received the highest score and its approach to quality, safety and level of personnel experience were contributing factors.”


To manage financial risks, Mn/DOT took responsibility for site excavation out of the contract because it was such an unknown. The former bridge had been built on the site of an old coal gasification plant and no one knew what levels of contamination were in the ground.





“When Mn/DOT agreed to pay for remediation of the site, we took the financial risk away from the contractor,” Mr. Chiglo explains. “That way, they could bid a number they were comfortable with, without fears of unknown costs, and we saved money because we paid for the actual cost of excavation, not an assumed cost.”

Mn/DOT is also using a delivery process allowing construction to begin after a portion of the final detailed design has been completed, Mr. Chiglo says. Because it allows for an overlap of design and construction, the process speeds delivery and provides the teams with an extended project roadmap to use as they move forward.

“We do all the engineering and planning upfront so we have a written plan, complete with drawings, that lays out everything we need to do,” Mr. Sanderson says. “We have written procedures for every type of work we do on the site. That way, there are no surprises.”



Given both the high level of scrutiny and the sizable safety risks associated with clearing the debris and rebuilding the bridge, the Flatiron-Manson team has implemented several risk-management strategies. The most obvious is having seven safety officers on site—a typical bridge project of this size would have one or two.

“On this project we want to better our current corporate aim of having half the number of safety and lost-time incidents than the industry norm. We look at both of those issues and the risks related to them constantly,” Mr. Sanderson says

“Safety is always important on a project, but in this case it's magnified,” Mr. Chiglo says, adding that the team also partnered with the Minnesota Occupational Safety and Health Administration.

Unlike some projects that have weekly or daily risk-assessment meetings, Mr. Sanderson meets with his team several times a day to identify potential problems.


There is a tremendous amount riding on how safely and successfully we do our job. The slightest problem could land us on page one of the newspaper.

—Peter Sanderson

Number of safety officers on site

Then, Mr. Chiglo, Mr. Sanderson and their teams meet every Monday and Thursday to talk through schedules, deliveries, progress and any issues that arose over the past few days.

“We are continually looking at risks and what's going to happen next,” Mr. Sanderson says. “That's how you get the job done.”

To reduce the risk of injuries or equipment failure, for example, the Flatiron-Manson team is using major cranes that are “as new as possible” and boast significant excess capacity. And lucrative safety incentives have been built into the payment plans for supervisors and team members to encourage safe work habits.

The project team is also devoting a greater number of resources to the project to help meet the tight deadline—safely. That includes running three drill-shaft teams instead of one and using three times the number of wood forms for the pre-cast concrete elements so they can be poured and set simultaneously.


Mr. Chiglo also credits a shared office space on the bridge site with helping the teams meet deadlines. “A lot of problems on projects come from a breakdown in communication,” he says. “We avoid that because we are co-housed. If issues arise, Mn/DOT, Flatiron-Manson and [another project partner] Figg Engineering are together full-time so they can be resolved quickly.”

And those issues arise daily. Recently, Mr. Chiglo's team had concerns about the grouting of the bridge's post-tension strands. “Because we were co-housed my team was able to sit with the group from Flatiron and the designer that day to work through the issues and come to a resolution,” he says. “Normally those types of issues can take quite a long time to resolve, but we were able to continue moving forward with our design.”


In this industry, there are always hiccups. If you do not address them as soon as possible, they may fester and become big problems.

—Jon Chiglo

Instead, Mr. Chiglo met with the Flatiron-Manson team and together they were able to make adjustments in the field that day. “In this industry, there are always hiccups,” he says. “If you do not address them as soon as possible, they may fester and become big problems.”

But even all that extensive risk-management planning couldn't solve an unexpected setback that occurred on 9 January, when a tanker trailer rolled over, spilling 8,000 gallons (30,283 liters) of unleaded gasoline into a storm sewer. Although the accident happened three miles away, the gasoline emptied into the Mississippi River right at the bridge construction site.

“We were completely unprepared,” Mr. Sanderson admits.

He had no choice but to stop work while the city's fire department flushed the gasoline from the storm sewer with 30,000 gallons (113,562 liters) of water and booms were installed at the sewer outlet to collect and soak up gasoline flushed from the sewer.

“We lost a half a day that we won't be able to make up,” he says. “But sometimes totally unknown things happen, and you can't get excited about it. You just have to move on.”

Despite the lost hours, Mr. Sanderson and Mr. Chiglo say they remain optimistic about meeting the deadline. “I am confident we will make that date,” Mr. Chiglo says. “And we will do it with a high-quality, safe product.” PM

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