The plan in 2013 was to have all 510 cars being Flexity come Aug 31, 2014 when the line went back in service and that was 18 cars alone. As time went on, the numbers keep decreasing to the point there was only 2 ready for service with 4400 and 4403 being the 2.
On Aug 31, 3 years later, we had 40 cars in service, averaging 12.66 cars a year for delivery. With 4442 now in service, we have 41, since 4401 is still a non TTC car and still has to be rebuilt as well do its burn in like 4400 and 4402 had to do when they were rebuilt.
At the same time, pantograph was to be used on 510 in 2014, yet no pans 3 years later. TTC decided not to use pans on 510 until 501 & 504 were converted to pans schedule for for late 2015 or early 2016, yet still not done and more like 2018 or 2019 since a number of intersections still have to be rebuilt.