The limits of the block are from Y to PD. Since this manual block territory an eastbound train will recieve a Clearblock at Y and only one train at a time occupy the the tracks between Y and PD. So a second eastbound following right behind the first one would be held at a stop signal at Y until the 1st train entered PD interlocking.
Although the signal you mentioned next PD tower is a home signal (on the LIRR any signal that can display stop is a home signal) it is not THE home signal for PD interlocking. Traveling east from Y the first signal you see (the signal with the numbers) is the Distant Signal to PD, it governs trains approaching the home signal. The next signal is PD's home signal or Westerly Limit.
Although the signal you mentioned next PD tower is a home signal (on the LIRR any signal that can display stop is a home signal) it is not THE home signal for PD interlocking. Traveling east from Y the first signal you see (the signal with the numbers) is the Distant Signal to PD, it governs trains approaching the home signal. The next signal is PD's home signal or Westerly Limit.
