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Upgrades in materials and components should allow light-rail tracks near Providence Park to serve for up to 30 more years before needing additional overhauls.

The previous time repairs were made to the complex system of mechanical switches and sections of track around the stadium was the mid-1990s, according to TriMet project manager David Sauter.

鈥淭hat’s pretty good considering we’re getting double the trains and it was last done roughly 25 years ago,鈥� Sauter said Wednesday morning as he surveyed the job site along Southeast 18th Avenue in front of Providence Park’s east end.

There, general contractor Stacy and Witbeck is starting to replace MAX track switches and sections of rail. In addition, upgrades will be made to the track bed and drainage for the mechanical switch machines under the tracks.

Stacy and Witbeck previously worked on MAX orange-line infrastructure when it was built between downtown Portland and Milwaukie.

鈥淲e’re replacing three switches that make up a single crossover and a turnout to our special events track,鈥� Sauter said. 鈥淭he single crossover allows our trains to go from eastbound to westbound track, and the reason this is important is because often we need to juggle trains around the system, moving trains over from eastbound to westbound, or over to add service or rescue trains that have become stranded for maintenance issues.鈥�

Finally, new rubberized devices known as boots will be installed next to the rails along this stretch to reduce concrete chipping, or spalling, as well as keep potholes from forming. To secure the rails in place, an elastomeric grout will be used; it’s also expected to impact energy dissipation and electrical isolation.

Such tools did not exist 25 years ago, which led to the steel rails being permanently affixed to the asphalt at that time. Over the years, vibrations through the rails have displaced them slightly, though usually only a millimeter or two. But that can nevertheless have a noticeable impact, according to Sauter.

鈥淏ack then, things were done a little differently than they are today,鈥� he said. 鈥淛ust a few millimeters of movement in the rail translates to quite a bit of sway in the train. So that’s one issue and one reason why this is a priority.鈥�

When it comes to drainage, another outdated ’90s technique is being addressed. At that time, it was common to construct drainage systems featuring pipes that gradually became larger as they moved from storm drains to the wastewater system.

鈥淭his leads to problems because the pipes are grouted in together and the connections get frayed,鈥� Sauter said. 鈥淧ressurizing them to clean them, you actually get blowback, and we actually can’t get good pressure on the pipes.鈥�

So, a single-diameter drainage pipe will be installed through the length of Southwest 18th Avenue being upgraded.

Taken together, the poor drainage and degraded asphalt also led to false alerts in localized sensors that signal trains’ presence. But with better drainage and tracks, such malfunctions should be a thing of the past, Sauter said.

The project notably will disrupt service of blue- and red-line trains from May 6 through May 11. Some downtown streets and crosswalks have been closed since April 30 in anticipation of this work.

Also, orange-line service will be limited during commuting hours, according to TriMet, but disruptions overall are not expected to be as severe as previous ones in the area.

According to TriMet, automobile detours, shuttle buses and free bike rides on Biketown will be offered until MAX service is fully restored.

鈥淒uring the project we will only have blue-line trains running on the west side between Hillsboro and Goose Hollow,鈥� TriMet spokeswoman Roberta Altstadt said. 鈥淭hat means folks in that area will have fewer trains. But we are encouraging riders on the west side and anyone going through the disrupted area to plan an extra 30 minutes to their trips.鈥�