This week, the Metropolitan Council was set to vote on submitting its staff’s design plan for the Southwest light-rail corridor for approval by the communities affected — until Gov. Mark Dayton called a “timeout.” The proposal called for existing freight-rail lines to remain in the Kenilworth corridor in Minneapolis and for the new light-rail trains to be buried in shallow, cut-and-cover tunnels through most of the residential neighborhood along the narrowest parts of the corridor.
To many residents of the Kenilworth area, this represented a breach of faith, since they had been assured, when freight trains were reintroduced into the corridor 17 years ago, that the trains would be temporary, staying only until a new freight-rail connection through St. Louis Park could be established.
It is natural, in such circumstances, to ascribe malign intentions to those who are perceived as reneging on the earlier commitment. However, knowing most of the parties involved in making those earlier promises (at least those who are still at the table) and having studied the issues in detail, I have come to believe that this is unfair.
I believe that, at the time those assurances were made, everyone at the table, including the railroads, sincerely accepted that if there were a practical way to relocate the freight-rail trains to St. Louis Park, it would be the right thing to do. I am also convinced that everyone at the table believed, in good faith, that it would, in fact, be practical.
Unfortunately, subsequent detailed engineering analysis has proved this assumption wrong.
The nub of the issue is that the east-west rail line lies 26 feet below the north-south rail line at the point where the lines intersect in St. Louis Park. Since freight-rail trains can handle a grade of no more than 2 to 3 percent, the east-west tracks would have to begin their ascent about a mile to the west. Once the grade change had been negotiated, the design that all of the parties had originally envisioned would have called for eastbound trains to make a left turn to merge onto the north-south line, which then turns to the right, then back to the left, before straightening out and heading gradually downhill as the line moves north.
A number of interested parties have observed that vertical grade changes such as these are commonly navigated by freight trains, as are horizontal curves as tight as those envisioned. However, what no one had focused on, until the Met Council’s designers inherited the project and began detailed, three-dimensional engineering, is that freight trains cannot simultaneously negotiate undulations of these magnitudes in the horizontal, vertical and longitudinal dimensions without placing dangerous levels of stress on both their couplings and their wheels that would create an unacceptable risk of decoupling or derailment.
Under the routings envisioned when the connection was first sketched out, different sections of a single freight train traveling along this section of track would have been moving up, down, left and right — all at the same time. This is just not safe.
No one is at fault for failing to see this earlier. Certainly none of the elected officials who were party to the original freight-rail reroute discussions had the engineering expertise to anticipate these issues. Indeed, not even the railroad officials at the table recognized them until they retained their own engineering consultants and conducted their own design analysis in three dimensions.
To address these issues, the Met Council’s engineers had to devise three-dimensional designs that would remove the “S” from the horizontal dimension and the “peak” from the vertical dimension. The best of these options is the so-called “Brunswick Central” design option, which replaces the “S” with a pair of more gradual left turns and replaces the “peak” with an elevated berm along Brunswick Avenue in St. Louis Park, eliminating the dip in the tracks that currently exists north of the intersection.
Unfortunately, this “least bad” option would cost $200 million, take out more than 30 homes and 11 businesses, and create a towering rampart that would literally divide St. Louis Park.
Any viable alternative proposal for rerouting the freight trains from Kenilworth to the St. Louis Park routing will have to similarly flatten out the grades and straighten out the “S” curves the way that the Met Council staff’s Brunswick Central design does, but at lower cost and without dividing the city.
As Star Trek’s “Scotty” liked to say: “We canna’ repeal the laws of physics, Captain!”
Steve Elkins represents Bloomington, Richfield, Edina and Hopkins on the Metropolitan Council. The opinions expressed in this article are his alone, and do not represent the views of the Metropolitan Council or its staff.