Some of the most noticeable work on the Valley Line Southeast is now in the sky—the Tawatinȃ Bridge, the elevated guideways and a Star Wars-inspired X-wing tower.
Here’s a quick tour of construction highlights on the 13 km LRT route that will connect people from Downtown to Mill Woods as Edmonton builds for our future.
Worksites have come to resemble festival tents. The orange and white tarps do important work. They keep heat inside, and rain and snow outside. Concrete doesn’t harden properly when the air temperature is too cold or if the concrete is too wet. To boot, construction workers get a break from the cold.
The north pier of the Tawatinȃ Bridge continues to grow up and out. Under the tarps, workers form concrete to create the bridge deck on which the train will travel. TransEd, the City’s partner building the project, is using a cantilever approach on the bridge deck. Workers extend a section from one side of the big concrete pier (the vertical tower), and then form one of the same size on the other side of the pier. This way, loads are balanced on either side of the pier. When all is set and done, TransEd will have used this process to build 41 sections.
Crossing the river to the south, the Tawatinȃ Bridge connects to an elevated guideway over 98 Avenue, the last train-only overpass to be installed on the project. Guideway sections over roadways are constructed nearby and then pushed up into place using special equipment. After crossing 98th Avenue on the guideway, Valley Line passengers will descend back to ground level at the Muttart Stop.
The same process for lifting the guideway was used to complete the route’s other elevated guideway, which starts along 83rd Street at Argyll Road and travels through the Davies Industrial Area before heading back to ground along 75th Street before McIntyre Road. This section will allow Valley Line trains to travel over Argyll Road and the nearby train tracks to arrive at Davies Station.
On a cold Friday night in November, the construction team closed Argyll Road to lift the massive concrete guideway into place.
⚠️Heavy Factoid Alert: People from nearby communities came out to watch the 37.85-meter- long, 780,000 kg mass of concrete as it was lifted up and artfully moved into place.
Mammoet used Self-Propelled Modular Transporters (SPMTs) paired with a push-up system to move the section of guideway to its final location over the road.
The SPMTs are massive. Each unit has 48 pickup-truck-sized tires. The axles of each SPMT operate independently. Using “barrels,” which are, essentially, reinforced steel boxes that stack together, the push-up system on each SPMT lifts the guideway incrementally.
Once the team had the guideway section up, the SPMTs began the hours-long process of slowly lowering and shifting the section of guideway into its final resting spot.
Precision was key word in the Argyll operation.
Not all sections are lifted at night. Other sections of the elevated guideway in the Davies Industrial Area, like the one pictured above near Wagner Road, went up in the day because the work didn’t affect traffic flow.
Elevated tracks in the Davies Industrial Area will mean LRT passengers won’t face delays waiting for freight trains to pass. And elevated tracks will allow the space at street level for a 1,300 stall park-and-ride facility and an integrated bus transit centre.
Back at ground level, the Valley Line LRT route continues south along 75th Street where it runs along and then crosses Edmonton’s high load corridor. The high load corridor is the route used by Edmonton’s manufacturing sector to transport oil and gas equipment, modular buildings and other large steel and concrete creations, many of which are headed for projects north of the city.
Here was the Valley Line Southeast design team’s 6-and-9 challenge:
The typical height for LRT power lines is six metres. The high load corridor features nine-metre power-line clearance needed for the large vehicles and their payloads. Those oversized loads would be too tall to pass under the lower LRT power lines.
Here is the design team’s solution:
The X-wing, named by the Valley Line team’s Star Wars fans for its resemblance to the Rebel Alliance starfighter, is the first of its kind in North America.
Its steel arms will raise LRT power lines up to 14 metres so that oversized loads can safely travel below. This line-lifting process, which will take about three hours, will happen overnight, and not affect Valley Line operations.
Thanks for reading, and may the force of public transit be with you.
For those who want more, here’s a time-lapse video of the 98th Avenue guideway girder lift:
For past updates, see:
June 7, 2019: Taking Shape: a quick Valley Line Southeast tour!
August 15, 2019: Taking shape: Valley Line Southeast update 2
October 17, 2019: Taking shape: Valley Line Southeast update 3