I know that @Hal Pollner so how does the locomotive get into that "roundhouse"? I lived nerar a roundhouse as a youngster.
Sorry I don't. Didn't have a camera way back then. I think it's gone now because that whole area has completely changed since I lived there in the late 40s.
A spur connects the outer yards to a turntable located in the center of the roundhouse, which then rotates the locomotive to a specified servicing stall, which the loco enters. The loco enters the stall under is own power, except for the rotating of the turntable, which is done by an engine at the base of the turntable. Hal
I know how a round house works. As I said I live near one as a youngster and saw it operated many, many, many times.