This could be the C9 day room. C8- was the admissions building and was also locked. C8 and C9 were male buldings. After patients were checked in at C8 and processed, they would normally be moved to C9. The patient population in C9 was often older. I worked at Byberry from 1968 to 1979. I still have the key chain we used to get in and out of the buildings.
RK
Location: Philadelphia State Hospital (Byberry) Gallery: Depression