Question about local/express routing through Bryn Mawr

I've got a possibly stupid question about how trains on the R5 go through Bryn Mawr. Trains that express inside Bryn Mawr switch to the express track at that interlocking, I assume, but the portion of the interlocking to go from the WB express to the WB local track is West of Bryn Mawr. Do those trains stop on the inner track, and passengers cross the local track? Is that what those wooden mini-platforms are for? Or am I missing something?

Similarly, where do Bryn Mawr locals that terminate there go, exactly? Searching around I see they sometimes deadhead to Frazer, sometimes back to 30th St. For those that return to 30th St, the connection from WB to EB is East of the station, so how do they drop passengers off and then turn to head back East?

I'm curious about the reverse for EB expresses inside Bryn Mawr and where EB Bryn Mawr locals originate from.

The afternoon Bryn Mawr Locals drop off their passengers at the platform on track 4, then move west to the crossovers and come back east crossing to track 2 and deadhead back to Philly.
The morning (EB) Bryn Mawr Locals deadhead out on track 3, then reverse back and cross over to track 2 to pick up passengers. The train crosses to track 1 upon departing Bryn Mawr.

Nifty, thanks. I assume then that WB/EB expresses stop on track 2/3, respectively, then, and switch from/to tracks 1/4 after they leave the station? For the locals and expresses, what method is used to make sure no trains use track 1/4 when trains are stopped on track 2/3? Is it just the dispatcher making sure of it, or is there something set up that way in the interlocking or with the signals for protection?

NOTAC Rule 121 ...

Ah, makes total sense. Thanks for the info.

Wasn't there talk to move the Bryn Mawr cross over's west towards Villanova?

Last I heard they were going to have two halves: VILLA on one side of Villanova and NOVA on the other, with crossovers leading to the platforms in both directions from 2 to 1 and 3 to 4 (don't know about 2 to 3), but now that you mention it I haven't heard anything since.

I remember hearing the same plan, but after that all further discussion seems to have evaporated.

The (granted, obvious) naming scheme reminded me of something I read about a WWII ship called the Porcupine. After being split in two during an attack, the rescued halves were rebuilt into tenders ... Porky and Pine.

Might have been some ex-railroaders behind that--it does sound like two interlockings.

Is there a track diagram avaible for Bryn Mawr??

http://broadway.pennsyrr.com/Rail/Prr/M ... ynmawr.gif" onclick="window.open(this.href);return false;

Thanks much.

There has not been much talk about the Villa and Nova plan (which included the relocation of Overbrook east of its current location) because none of it has been funded yet.

Normal operation for express trains on the line: SEPTA trains that are express to/from Bryn Mawr and local stops west of that location generally remain on outer tracks #1 and #4 for their entire trips. Only the Flyer trips (nonstop 30th Street to Paoli) generally use Track #3 westbound from Overbrook to Paoli in the evenings (at least one of them overtakes and passes the train prior to it between Bryn Mawr and Villanova if both trains are on time). The two morning Flyer trips may use Track #2 all the way from Paoli to Overbrook, or (more usually) remain on Track #1 all the way, if traffic permits.

Do the Keystones usually use the middle tracks?

I think Keystones use the middle track between Paoli and Bryn Mawr only--at least I believe that's how it was when I rode it a week ago. They keep it on the outside tracks for the stop at Paoli, then it's on the inner tracks, but it goes back to the outside for the stop at Ardmore. I imagine sometimes they run it on the inner tracks East of Bryn Mawr too, to keep it from getting stuck behind a local, but when I rode it the Keystone leapfrogged Septa West of Bryn Mawr and then used the outer track.

Personally, I think it's a shame there aren't stations with island platforms between the inner and outer stations--Amtrak and expresses could run only on the inner tracks, allowing for much more flexibility in scheduling and leapfrogging. Looks like that'll be the case for Paoli when it gets rebuilt.