Yup,i guess that's the word i was looking for.I have seen something similar at BZA both at the South End & North End between platforms 6 & 7 if i am not wrong and also across many stations but always failed to find the word.I thought pitline was something that's located further away from the actual station,somewhere in the yard but was never sure.This dilemma was something that i have been carrying for a very long time and finally i can stop scratching my head.Thanks a lot for the answer along with the photograph to help me understand.Appreciate it,Yogesh Ji!!!!!!!