This is a Union Switch & Signal T-2 top-of-mast semaphore configured as a distant signal and cannot display stop or red. There is virtually no doubt the next signal is an "absolute" interlocking signal which by the then I.C.C. was required to display red unless the interlocking was cleared by the operator. Only then could this signal display clear as shown here. The lower aligned lamp is proof of it being an interlocking distant approach signal.