Crowds at the already busy Granville SkyTrain Station are about to get even worse as TransLink prepares to begin a major escalator replacement project that's expected to last two years. 

On Saturday, work will begin replacing the station's escalators, which were built back in 1986 and have been showing their age with regular breakdowns.

"They've served us well," said Sany Zein, TransLink's vice-president of engineering. "We've maintained them well past their expected life, which is typically 20 to 25 years, and now it's time to replace those units."

But replacing the six escalators, which currently carry about 30,000 people daily, won't be easy. TransLink said the narrow underground space in the station and the intricate nature of the work will require crews to close the Seymour Street entrance for the entire two-year duration.

"You can see the confined space we have," Zein told CTV News. "We have to have workers disassemble these units piece by piece, and then reassemble them with new components, which is why this will take about two years to do."

People will still be able to use the escalators and elevator at the Dunsmuir Street entrance.

Signs have already been posted at the station, and TransLink plans to add extra staff to help direct confused commuters who aren’t aware of the changes. But the transit provider warns that riders should expect bigger crowds and potentially longer waits.

"It will be congested. There will be some inconvenience," Zein said. "We're asking our customers to just be patient."

TransLink has recommended people who want to avoid problems consider using either Burrard Station or Stadium-Chinatown Station, which are a few blocks away.

The work will begin on three of the six escalators this weekend, and TransLink says there's a lot more to do beyond Granville Station. Another 37 escalators across the SkyTrain system need replacing, and crews are scheduled to begin that work in 2019.

With files from CTV Vancouver's Nafeesa Karim