I want to know the answer to the following question:
What type of motor was used in trailway traction applications?
All the background I'm provided with is that "In this application, the use of AC to power a motor originally designed to run on DC would lead to efficiency losses due to eddy current heating of their magnetic components, particularly the motor field pole-pieces that, for DC, would have used solid (un-laminated) iron and they are now rarely used.". Is that enough to answer the question?
Answer: no