Must be a fancy pedestrian walkway! Also amazing that somehow they can’t estimate the cost to within less than a $400 million difference
There's often tremendous variance in cost of construction materials over time. Especially in a time of high inflation and random tarrifs, project delays will result in changes in material prices and likely increases in labor costs.
Plus, demolition often involves an element of unknowns, especially with something like this, there's a good chance the as-built drawings don't reflect the actual conditions. There's got to be some wiggle room for that, too.
It does add up to pretty wild that high end is more than double the low end, but big projects are like that.
This is more of a construction management problem. Two vendors went bankrupt and coordination between the tunnel construction and baggage system was terrible. I've seen pictures of that project showing where concrete footings for conveyors didn't line up across a contractor boundary. This was not primarily a software problem.
A few things the article gets wrong - there were in fact long negotiations before ground was broken - and signed contracts. The CEO is continental was one Frank Lorenzo - and for a variety of reasons he played political games with the FAA and Denver before he was kicked out - and forbidden legally from ever running an airline again.
Part of what also happened is that united passed conditions o designed to cripple Competitors at Denver - going so far as demanding that the bridge between the main terminal and A concourse (where continental and other airlines were located) be frosted to make it less appealing for Continental customers. It’s also the reason why terminal b is physically wider then A or C.
The article doesn't talk about why they built it, really, but the big reason is that the old runways for the airport were so close together that any sort of weather dramatically reduced capacity at the airport (to the point that the old Stapleton Airport at Denver was the number one delayed airport in the nation, a really big problem when there were sometimes between three and five different carriers hubbing there).
A good example of something that the engineers got right - they replaced a heavy steel structure for a glass roof on the main terminal with a tent. (this why concoursesA,C and especially B have glass roofs while the maybe terminal has white canvas. Not only did this end up being a massive cost and weight savings - it gave the airport its iconic shape. Despite planning on a 10-year refurb cycle for the roof, they haven't had to replace it once.
the last vestiges of the old barge system are finally going away - and the tunnels are being reclaimed to provide a walkway to concourse B and c.
Why are they doing that now? Because the airport has actually been a dramatic success as a connecting and as an O&D airport. It now hubs three different airlines and is well over its original design maxes. They've been doing massive construction at the airport and are getting ready to break ground on two new concourses to continue to meet the demand.
Each of these projects are qre dramatically cheaper than competing efforts of other airport with tens of billions of dollars to refurbish extraordinarily constrained terminals and runways. Over the long run, it seems like a pretty good decision to build the airport, even if it got a rough start.