Signaling standards and twin semaphores

[Kiha66]

I recently came across this picture of what look to be two semaphore signals right after one another, and was wondering what the point of such would be?  Also somewhat related, where would be a good place to learn standard signaling practices, particularly with regards to JNR, and the placement and types of signals? 

http://photohito.com/photo/orgshow/2097108/

[westfalen]

I think you'll find they are for a junction or passing siding ahead, one signal for each diverging track.  Japanese semaphore signalling was based on the British route signalling system where there was a separate signal for each track at junctions.  The two signals are probably closer together than they look in the photo.  The train appears to be coming towards the photographer explaining why they are both at stop.  The taller signal would be for the mainline and the shorter for the secondary route or siding.