PRR Track Plan

[DKS]

I guess I'm just not seeing the operational advantage of this arrangement. At least with the scissors to the right instead of the left, they can be curved if need be, which would pull the throat away from the station. This arrangement pushes the platforms further to the left, especially the center one.

Here are the various configurations I've done so far, arranged to compare lengths.
 

 

 

[eric220]

I guess I'm just not seeing the operational advantage of this arrangement. At least with the scissors to the right instead of the left, they can be curved if need be, which would pull the throat away from the station. This arrangement pushes the platforms further to the left, especially the center one.

The problem with the other arrangements is that the platform tracks coming off of the slip switches only have one route to them. That means that a train going to one track will completely block the other. The extra crossover gives trains on tracks 3 and 4 an escape if the slip switch is blocked by a train trying to get to track 2 or 5.

In looking at it again, if there's room, an alternative would be to put a switch in next to the slip switch on tracks 2 and 5. From there, extend those tracks to the right until they intersect with the leads to tracks 1 and 6. Then trains from 2 and 5 can run around the slips if they're occupied.  I'll have to draw it up later.

[DKS]

The problem with the other arrangements is that the platform tracks coming off of the slip switches only have one route to them. That means that a train going to one track will completely block the other. The extra crossover gives trains on tracks 3 and 4 an escape if the slip switch is blocked by a train trying to get to track 2 or 5.

In looking at it again, if there's room, an alternative would be to put a switch in next to the slip switch on tracks 2 and 5. From there, extend those tracks to the right until they intersect with the leads to tracks 1 and 6. Then trains from 2 and 5 can run around the slips if they're occupied.  I'll have to draw it up later.

Much simpler to just add two more double-slips. And if you did that, you could conceivably mix Atlas and Peco without much headache. The top version is all Peco; the bottom has just Peco slips and nice, long #10s for a sleek throat that should look and work really well.
 

[Philip H]

David,
With a great deal of respect (and wishes for a speedy recovery) I am not sure how either plan qualifies as simple . . .

[Ed Kapuscinski]

I've got to say, while I absolutely understand Eric's desire to have the look of a busy passenger terminal, I think operations through this are going to be nightmarish. For example, even though you can have multiple routes through there, I think, in reality, actually operating through both routes is going to happen VERY infrequently.

And if it's going to happen very infrequently, I think you're going to find that the expense and headache of building and maintaining such complicated track work is going to far outweigh the "coolness" factor you'll actually experience.

I hate raining on parades, but I really think you'll enjoy a simpler solution when put into practice.

[DKS]

David,
With a great deal of respect (and wishes for a speedy recovery) I am not sure how either plan qualifies as simple . . .

Well, I'd like to qualify these posts with the personal preference of abandoning such complex trackwork, which seem to exist almost exclusively for aesthetics and those extremely rare occasions where the traffic warrants it. I'm with Ed, to be sure, and my recommendation was and still is for just a handful of #10s...
 


But, of course, Rule #1 applies, and if Eric wants a strip of spaghetti leading into his passenger terminal, then that's what he should build. I was just trying to lend a helpful hand.

[conrail98]

David, I'm with you and Ed on this one. I'd really like to understand what the operations aspect of this are. I operate on a large layout that has a passenger terminal to represent Jersey City that has 2 crossovers and one double-slip to get into the 8 platform tracks and engine terminal in the terminal itself along with a holding area going into the throat. What we've found is the passenger trains end up waiting in the holding siding prior to the terminal anyways because the terminal operator needs to ensure a track of appropriate size is open or ensure the lead route is open due to their switching. If you are going to have a terminal operator, they're most likely always going to hold an inbound on one of the two tracks in the lead into the passenger terminal just to keep things easier for themselves.

For this plan, I'd flip the left-hand and right-hand crossovers so the right-hand occurs just at the end of the curve's easement to avoid the nasty s-curve being created with the left-hand in your plan. That "may" extend the the throat slightly, but with long passenger cars it'll improve performance through that area,

Phil

[MichaelWinicki]

I've got to say, while I absolutely understand Eric's desire to have the look of a busy passenger terminal, I think operations through this are going to be nightmarish. For example, even though you can have multiple routes through there, I think, in reality, actually operating through both routes is going to happen VERY infrequently.

And if it's going to happen very infrequently, I think you're going to find that the expense and headache of building and maintaining such complicated track work is going to far outweigh the "coolness" factor you'll actually experience.

I hate raining on parades, but I really think you'll enjoy a simpler solution when put into practice.

I think you hit upon something important.

Can you imagine having a switch fail or one of the points fall off and then have to pull up everything else, just to replace one switch?

[DKS]

I'd flip the left-hand and right-hand crossovers so the right-hand occurs just at the end of the curve's easement to avoid the nasty s-curve being created with the left-hand in your plan.

That's actually a right-hand, so as to minimize just what you're talking about (hard to tell, I know), as well as shorten the lead into the throat just a scratch.

[conrail98]

That's actually a right-hand, so as to minimize just what you're talking about (hard to tell, I know), as well as shorten the lead into the throat just a scratch.

Ah, ok. Yeah, it looked like the opposite way from the drawing,

Phil

[eric220]

I hate raining on parades, but I really think you'll enjoy a simpler solution when put into practice.

My parade is pretty soaked by now.  I've debated back and forth about the relative merits of a complex throat versus a simple throat.  I'm just not convinced that the more complex track work is going to be as unreliable as everyone is making it out to be.  My current layout is turnout-heavy, almost exclusively #5's, and I don't have any problems with it.  Then again, maybe I'm just spoiled with the Kato equipment that I run.

The simple design that DKS presented has 8 turnouts, and requires a train to traverse a minimum of 3 turnouts and a maximum of 4.  The first two versions I present below each use the same 8 turnouts plus 2 double-slips.  They require a train to traverse a minimum of 2 turnouts (3 if you count the double-slips as 2 each) and a maximum of 4.  In other words, is it really that much more complex?

DKS - Here's the modification that I was referring to in an earlier post using the Peco track.  The extra double-slips probably aren't necessary.  Tracks 1 and 6 really don't need a second route because there's no potential hazard beyond them that they would have to avoid.  



And here's the same modification to the mixed version.



Given all the length required to reach tracks 1 and 6, I realized that there's actually room to do away with the slip switches and replace them with #10 crossovers if I wanted to.  Not so sure about the result, but here it is.

[DKS]

My parade is pretty soaked by now.  I've debated back and forth about the relative merits of a complex throat versus a simple throat.  I'm just not convinced that the more complex track work is going to be as unreliable as everyone is making it out to be.  My current layout is turnout-heavy, almost exclusively #5's, and I don't have any problems with it.  Then again, maybe I'm just spoiled with the Kato equipment that I run.

The simple design that DKS presented has 8 turnouts, and requires a train to traverse a minimum of 3 turnouts and a maximum of 4.  The first two versions I present below each use the same 8 turnouts plus 2 double-slips.  They require a train to traverse a minimum of 2 turnouts (3 if you count the double-slips as 2 each) and a maximum of 4.  In other words, is it really that much more complex?

DKS - Here's the modification that I was referring to in an earlier post using the Peco track.  The extra double-slips probably aren't necessary.  Tracks 1 and 6 really don't need a second route because there's no potential hazard beyond them that they would have to avoid.  



And here's the same modification to the mixed version.



Given all the length required to reach tracks 1 and 6, I realized that there's actually room to do away with the slip switches and replace them with #10 crossovers if I wanted to.  Not so sure about the result, but here it is.

Well, "complexity" is certainly a relative term, since there's visual complexity and operational complexity. One could conceivably design a throat with four times as many switches as a simple version, whereas the simple one requires a train to traverse twice as many of them for a particular route, so I don't think this is necessarily a good measure of the term.

Be that as it may, I think your third option presented above may be the very best version to date. While it has no double-slips, I think the crossing alone provides a satisfying level of visual complexity; plus, it makes use of long, elegant #10s that will look good and should present fewer operational issues.

Here's what Anyrail makes of it:
 


Edit: It dawned on me that the tracks at the far end could be brought together sooner for a tighter look by flipping around some of the switches--

[John]

shouldn't the X over be farther to the right to allow for trains on the outside tracks to make it to either of the mains?

[DKS]

Eureka! All #10s, and just a scratch over 3' long:
 

shouldn't the X over be farther to the right to allow for trains on the outside tracks to make it to either of the mains?

Eric says there's another set of crossovers further down the line to the right.

[Ed Kapuscinski]

I like the latest version.

Eric, you're definitely spoiled/lucky. Honestly, I think even with the simplified plan, you've got to prototype it and test it before final installation.