There are some terminal stations which doesn't have coach maintenance facility; so rakes of trains operating from these stations have to be compulsorily moved to nearby coaching depots for upkeep & maintenance. 08601 represents such an 'empty rake' movement.
You'll find similar movements between CAPE & NCJ as well; Most of the trains operating from/to CAPE like Himasagar/Gurudev/Kanyakumari Express are maintained by CD/NCJ.