San Francisco historic PCC's restricted from N Line?

[Septaman113]

I noticed inside the PCC's and the other old streetcars that there was a sign right above the driver that stated " DO NOT OPERATE ON N LINE". Why is that? The end of the N has a loop,so I was wondering. Thanks.

[lensovet]

technically, the PCCs aren't supposed to run on ANYTHING other than the F line. all the LR lines have just that – light rail cars – running on them.
my guess for why the N was singled out is that it crosses with the F somewhere and it's just a reminder for the PCCs to not go on N-only trackage by accident.

[jwhite07]

The N is the one that goes through the Sunset Tunnel, right? I seem to recall being told while I was on a charter back in 2000 that historic cars could no longer use that line because the Sunset Tunnel had been equipped for cab signal operation, and historic cars don't have cab signals.

We did go to Ocean Beach on a charter I was on in 1996, apparently pre-cab signals. I got a nice side-by-side photograph of two different generations of Italian cars - Milan Peter Witt 1834 (which was tucked away on the stub track there for our lunch break) and the then-brand new Breda 1400-1401-1402 undergoing acceptance testing.