Metroliner speed thru double slip switches

I don't get this "question".

Double slip switches in real life are almost exclusively found in passenger terminal areas.  A few exist in other areas where there is not enough room for a connecting track, but the main use is to provide a large number of alternative routes within a passenger terminal.  

The double slip switches at Los Angeles Union Passenger Terminal had a 12 MPH speed limit and every other place I have seen double slip switches used, the speed limit was 10.  They are maintenance-intensive, and serve a specialized purpose.

I have never known of one having been located on a high speed main track, but there could be an odd situation in which there is actually one.

Are you sure you are not referring to a double crossover?  I do not see where a double slip switch would be used at Trenton.  I can not find any reference or photos showing one at Trenton.  The Metroliners do not stop at Trenton and just fly through on the center tracks where there are not even crossovers that I recall.

Enclosed drawing is of Fair from The Broadway web site.  There appears to be double slip switches on both Amtrack nonstop tracks.  I question if I am correct how does that work?  Seems to me, a nonexpert to be a recipie for big time trouble. 

I agree.  They sure look like double slip switches.  It is an old drawing, almost 50 years old.  I do not think they have been in the mainline for a long time.  I rode that line in 1967, date of drawing, but I do not remember the track arrangement around Trenton.  I was going from Philadelphia to Dover AFB on an express train of MP 54s. What a ride!  We were going as fast as the cars could go, standing load, in the dark, cars seemed about to fall apart. They still had wooden window sash and the Metroliners had been sucking the glass out of them when they passed at speed.

More recenty, since Amtrak, I have ridden from Philadelphia on SEPTA/NJT To NYC. Have to change at Trenton since the commuter lines do not go thru any longer.  The PRR sure did a heck of a job running the NE corridor. 

I was just in Trenton station twice a couple weeks ago, changing trains from NJ transit to SEPTA. I did not see any double slips, but several single and double crossovers.

The regional Metroliner does stop at Trenton, and express trains pass through at far less than 150 mph, more like 40mph. Its a very tight track arrangement at the station.

I posted this query because the drawing,though probably correct seemed troublesome.  The need for crossovers there was obvious since SEPTA trains terminated there inside or outside of north platform, and then had to crossover to other side to south platform.  outside or inside platform track?  Conversely NJ Transit terminated on southbound platform, inside or outside track?  Thence it had to crossover to north platform, inside or outside track to begin new journey northbound. 

Under these conditions a set of double slip switches or simple crossing tracks would make sense.  HOWEVER it creates havoc for high speed train travel on Amtrack thru tracks. 

i was curious if I was alone on wondering how this worked or if it did not work long term. 

mikeg

Here's a better copy.  It appears that there are three double slipswitchs where the tracks diverge toward the top of the diagram.

http://broadway.pennsyrr.com/R...r/Maps/Itlk/fair.gif

Jan

Westbound NJ Transit trains stop on tracks 4. The SEPTA train uses track 7. There is another platform not shown.

Inbound SEPTA trains from the west crossover from track 2 to track 7.

On my last trip from 30th St. in Philly, I rode the first car and listened to the engineman and dispatcher discussing running against traffic into Trenton station. Crossing from track 2 to 3 takes place west of the coalport-hamilton overpass, from track 3 to 7 happens within the interlocking shown.

Jan, keep in mind that you are looking at a diagram from 1967.  There was no Amtrak and SEPTA and NJT did not operate commuter service to Trenton. The PRR or PC operated the commuter service through Trenton, the state line making no difference to them. Most of the track special work at "Fair" including those slip switches are gone now. Because the computer service is state operated and funded, both SEPTA and NJT turn back at Trenton, which is close to the state line. 

Your track numbering confuses me. It might just be me. Track 1 is inside of northbound platform.  2 &3 are the Amtrack thru tracks. 4 is southbound inside of southbound platform. 5&7are outside of southbound platform.  Where is coalport hamilton overpass? Hamilton Ave never crosses the railline.

I have a pix from Irene with 2 SEPTA trains sitting in the water presumably with all the traction motors destroyed.  They were on 5&7.  Is there another platform there where 6 was?  When I commuted 6 was still there.  With PRR, there were no double slip switches in the 50's when I was a struggling college commuter.

NJT uses track 4, both for arrivals and departures?

Was there a crossover from 2 to 3 on Amtrack's track between the Delaware River bridge and the station?

Trying to understand all.  Time changes things.

mikeg

I notice that dwg has a November '67 rev date on it,  It needs to be remembered that prior to the Metroliners, the inside pair of tracks were used for through freight trains, and up until that date there were still a lot of them.  Freights via the low grade Phily bypass came on and off just across the river at Morrisville, while frts going up the Bel-Del to bypass New York were also significant prior to the Penn Central merger.  It looks to me like the limited distance between the east end of the platforms and the Bel-Del branch at the upper right is what determined the need for slips here, especially to get a nb Bel-Del across the wb psgr tracks after a wb psgr had arrived.   It's interesting to note that the two "passenger mains" did not have slips. 

Best rgds, SZ

In the 50's there were no double slip switches. but rather crossovers as per standard PRR 4 track interlockings.  It is correct re track 3&2  were usually used for freight and the 1&4 track for passenger; however during morning rush #2 and sometimes #3 were used for passenger trains northbound to NYC after proceeding thru Fair and Midway.  I was on one northbound on #3, which due to someone not paying attention ended up on track#3 in the Newark Station.  This obviously had the trainmen and station personel very haggard trying to keep the southbound passengers from boarding it.  While it was on 3, 2 next to it was empty. 2 was where it should have been.

mikeg

Mike,

I'm a little confused myself about which track I arrived from the west on NJT. I do know for certain that SEPTA comes and goes on track 5. the eastbound NJT train left from the 'north low track'.

here is a photo looking east from the track 4 platform. on the right is FAIR tower. you can see crossovers in the trackwork, but no slips.

It seems to me that SEPTA would better cross over at morris from 1 to 4 and then run against traffic to the station.  I went thru all my pix and two different mapping programs and could find no evidence of a switch from 2 to 3 and 3 to4 involving the Amtrack rails 3&2. 

In Chris's post immediately above there is a southbound train, probably NJT.  The pix shows xovers between 4&3 and 1&2.  How does the train get over to 1 or 0 track for return.  Millham and Nassau are nonexistent now.  Are there complete crossovers here at Fair but just not visible?  Or do they crossover at Morris?

Went to Google maps again and on center track of Phila cutoff is a 8 car 2 engine passenger train.  This probably answers my question. 

Not trying to beat a dead horse, just curious how it works.

mikeg

Went back to Google and old morrisville yard is now NJT Morrisville yard.

Who knew.

mikeg

Summary

Even NJT knows that property taxes are lower in Pa.  Really bad pun.

The Broadway and Congo went thru Trenton on #2 & 3, no stoppe.

Metro liners on #2&3 could cruise thru at high speed; no significant interlocking at Fair.  Apparently Fair's function is switches for station.  Two platforms only.  Bordentown secondary & Belvidere no longer connect to mainline or in case of Belvidere no longer exist.

While not specifically relating to my model with 3 platforms etc, it has been very informative. 

mikeg