During the late evening hour, we watch NS 335 (Macon,GA-Sheffield,AL) with the terminal local crew NS AC29 in charge as they pull 60 cars from it's train out of receiving track 6, and by order of north tower to drop off a block of 30 cars on the receiving track 12. In the process of doing this, they had to ask for a signal from CT-Dispatcher at Control-Point East End Avenue (MP-337.5) from the arrival/departure track. Due to the length of the manifest the crew also had to ask for a signal at Control-Point Main St. to pass the block, and clear the switch on the lead track, and make the shovel move back to receiving track 12.