The Transcontinental PRR

[davefoxx]

For a yard this size, there's only going to be one master retarder, so there's only a few inches lost on each track due to the grades.

That doesn't seem very PRR-like, especially for a transcontinental version.  It would seem to me that, to look correct, you would want to have at least multiple retarders (even if they're fake) to get the look of a busy hump yard.  I fear that you may have too much selective compression, and it's not going to look right.  In other words, the PRR wouldn't bother with the expense of building a hump for this size yard.  Let's figure out how to expand on your design to make this work.  "Cause, if done right, it could be really cool.

DFF

[Ed Kapuscinski]

Sorry to be so late to the party.

Eric, when you're working with a hump yard (or any classification yard, for that matter), you need a minimum of three sub-yards:

1. An arrival yard. This needs to have easy access to the mains and to the classification lead. Terminating trains terminate in these tracks (so you'll also need easy access from these tracks to the incoming pit tracks and caboose servicing tracks), and through trains make setoffs here (hence the reason you need easy access to the mains). You don't need too many of these tracks, but the fewer you have, the faster your yard jobs need to power through the cars they need to classify to free up space for more inbound trains. If you don't have enough, your dispatcher will hate you and your road crews will rack up lots of overtime in the hole.

2. A classification yard. This is where the incoming trains are broken down into new blocks (note, not usually full trains, just blocks). You need at least as many tracks here as you have destinations, but they can be as short as your largest anticipated block. If you don't have enough tracks, you can dump the non-classified cars into a single track for reclassification later, but this is a waste of labor, since each car might have to get handled a few times. This is what the hump does, it speeds the classification process up by not needing to reach into a track, make a cut, pull out, push into another, etc...

Cars from the arrival yard get moved into the class yard by a yard job that's doing classification. They pull the cars from the yard onto a lead, from which they sort them. You want this lead free from as many interfering moves as possible, since every minute that your yard crew is not either retrieving cars from the arrival yard or classifying them is going to have a ripple effect across the layout (trains backed up waiting to get into the yard, or trains not departing on time)

3. A departure yard. This is where the blocks from the classification yard get made up into trains, get their power, their cabooses, their air tests, and leave. This yard needs good access to the "downhill" end of the classification tracks (away from the crew classifying cars) and good access to the mains for departures.

Cars from the classification yard move into the departure yard by a yard job that's often called a "trimmer". There should be a dedicated lead for this, but it's not as important as the other end of the classification yard because there are much fewer moves being made on it (moving a few blocks per train, as opposed to each and every car). You can often use this crew to do the other yard work too (like fish out do not hump cars, spot company service cars, hostle power, etc...).

In your plan, even with the flat yard moving inside the mains, I only see two of these yards, and I don't see a good facility for efficiently moving stuff between them.

Oh, and the thing about adding a PRR flavor to it all. While some smaller and less well capitalized roads would live with some inefficiencies, like using crossovers at both ends of the yard so both east and west mains can access the arrival and departure tracks, the PRR would say f*** that s*** and build some flyovers. That's why the tracks do that crazy thing at Antis. They needed easy access to the arrival tracks and departure tracks, so PRR moved some mountains and now nobody ever had to get in anyone else's way. Keep that in mind while you're designing it.  On Lee's WM, a track dipping under the whole yard so it would never be fouled by opposing traffic trying to get in would've looked out of place. On yours, it's almost a necessity.  Maybe you can route the one main under the hump?

[eric220]

Well, while everyone was responding, I played around with pinwheeling the west ladder and came up with this.



Same 8 class tracks, (forgot to mention, all #7's or #3.5 Y's) minimum track length is over 70".

For clarification, here's the whole yard complex.



I'll reiterate, although the "main" is used to move cuts back and forth from the A/D yard and the class yard, it's really not a mainline at this point.  It's more the track for the continuous running option.  I don't think it's going to be a major issue; pretty much every freight moving through the area will originate or terminate at the yard.  That just challenges the dispatcher a bit.  I also acknowledge that the yard is very small for the major division point that it's supposed to represent.  Unfortunately, I've only got so much room to work with.

[Ed Kapuscinski]

Ok, here we go.



There are a few minor changes, and a major one.

Add a crossover at A. This will allow your trimmer crew to pull blocks from the class tracks and build them into the departure tracks.

B. Loop your hump lead over the main and the rest of the stuff there. Put in a stone tower like Homer (cause it's cool: http://www.billspennsyphotos.com/apps/photos/photo?photoid=116823058). This will now give your hump crew direct access to the Arrival yard. This will also give you a lot more room to extend the class tracks. You should also extend the departure tracks so they're as long as your longest outbound freight, and maybe add another one or two if they can fit. These are much more important than the thing hanging off the back of the class yard.

C. I redrew the end of the arrival yard. I'm not thrilled with it, since it still could use better access to the engine servicing from that end (to not interrupt humping), but there's not much we can do. At that end of those tracks, you really want easy access for the hump crew, but they don't need to tie back into the main.

D. I added a crossover here so power can easily go from the servicing tracks to the departure tracks.

These mods will put you on a much better direction and get you the cool tower that's iconic to East Altoona.

[MichaelWinicki]

Those are good suggestions Ed.

The challenge I have is how everything is laid out.

The PRR knew how to lay out yards with as little wasted motion as possible... And I look at the moves/distance that a crew would need to take a cut of cars from the Arrival Yard and push them through the hump... Boy, that's a lot of distance and moves.

[davefoxx]

Ed,

That's some real good suggestions there.  I especially like how the class tracks can be extended by taking the hump up and over the mainline to connect to the arrival yard.  Well played, sir.

DFF

[seusscaboose]

taking the hump up and over the mainline to connect to the arrival yard.

didn't/doesn't Conway have a hump?  i konw you have to duck under some tracks when driving through there to get to the yard offices...

EP

[Ed Kapuscinski]

Those are good suggestions Ed.

The challenge I have is how everything is laid out.

The PRR knew how to lay out yards with as little wasted motion as possible... And I look at the moves/distance that a crew would need to take a cut of cars from the Arrival Yard and push them through the hump... Boy, that's a lot of distance and moves.

Not really. The crew can just reach into the track from the lead, grab the train, and over the hump it goes!

[MichaelWinicki]

The other point I forgot to bring up were "retarders".

They only came with the newest hump yards.

The PRR had a vast army of hump yards that were operated with brute force, a brake wheel and gravity.

The Olean yards were built in 1905 and were upgraded in the 20's... and no retarders were added.

And many of these antiquated hump yards survived into 60's... Olean's did for instance. 

Even the big PRR yard in Buffalo was without retarders... Maybe that's why it was called "Gravity". 

[Ed Kapuscinski]

Also, thanks guys.

I really enjoy yards and yard design. It really appeals to my inner process engineer.

[Hornwrecker]

Here is a diagram for a small PRR hump yard: Honey Pot Yard, near Nanticoke, PA.

http://pennsyrr.com/kc/maps/images/Honey_Pot_Yard.JPG

No idea how it got that name.

[MichaelWinicki]

Here is a diagram for a small PRR hump yard: Honey Pot Yard, near Nanticoke, PA.

http://pennsyrr.com/kc/maps/images/Honey_Pot_Yard.JPG

No idea how it got that name.

Yep Bob, Olean was similar except it was much larger and you had two hump yards side by side with the receiving/classification parts flipped from one side to other.

Very simple and straight forward... Using your image, the switcher enters the receiving track to the very right, pushes the train forward and over the hump.  Very simple.

[MichaelWinicki]

Not really. The crew can just reach into the track from the lead, grab the train, and over the hump it goes!

OK.  I stand corrected.  I didn't "see" the new blue track going from point C to point B.   Still a little odd because it's going to need to cross existing tracks to reach point B... Unless like you said Ed, you go over the existing tracking rather than cross them.

[Dave V]

That curve on the hump lead would give me fits...

[Ed Kapuscinski]

OK.  I stand corrected.  I didn't "see" the new blue track going from point C to point B.   Still a little odd because it's going to need to cross existing tracks to reach point B... Unless like you said Ed, you go over the existing tracking rather than cross them.

Yep, that's the plan. Up and over, like this: http://www.billspennsyphotos.com/apps/photos/photo?photoid=116823058 http://thecrhs.org/Images/Conway-overview-in-1983