The trains were poorly built.
Excerpt from the link (previous post):
Alstom to bring in ‘fresh, qualified resources’
Train manufacturer Alstom has a four-point plan to correct the issues in the system, including a plan to ‘uplift competencies of the leadership and supervision teams’ and ‘strive to regain a professional and productive work environment by injecting fresh, qualified resources.’
That left an incredulous Coun. Catherine McKenney asking why such resources weren’t here before.
"Now, after two years of constant dysfunction? Now, after we’ve shut down the system numerous times and had to run R1 service? After paying you 2.1 billion dollars for a system that does not function. Now after two derailments, the second one that could have been absolutely catastrophic. Now you’re going to bring in fresh and qualified resources?”