According to wikipedia the largest helicopter in the world, the mil-mi 26 has a payload capacity of 20 tonnes. It has exceptionally lifted 25 tonnes before but was then sent back to the factory for inspection before it was used again.Depending which published figure you believe ( they vary ) a Chinook can lift between 10-12 tonnes.
According to https://www.railengineer.co.uk/wp-c.../Table-1-Hitachi-800-802-orders-V3-Avenir.pdf a class 802 has a tare mass of 243 tonnes, if we assume all the cars weigh the same that works out to 43 tonnes per car.
The numbers just don't seem to work for lifting out a rail car by helicopter unless significant lightening work is done first.