Humongous

The Pennsylvania Railroad's four track mainline through the Alleghenies was the one of the busiest sections of railroad in the world. Designed for eastbound tonnage, trains from the west had all the advantages. Even so, a plethora of helper engines were still required going east. Reading Triumph I, I found myself wondering if I should have modeled the west slope of the Alleghenies from Conemaugh to Gallitzin. Would have been quite a different theme for a model railroad based on the Pennsy

Be that as it may, the fact remains that modeling any section of the Pittsburgh Division is not for the faint of heart. It's not so much the trackwork, or the scenery, or even fitting a site like Altoona into a two car garage. Yes, there is a preposterous quantity of track. There are, however, many multi-level layouts that use just as much, albeit with a single track mainline. Scenic elements like Short Mountain and Kittanning Point are over 30" tall in N scale, but the Rockies or the Sierras modeled by some are even taller. Most real Class 1 railroad facilities can not be modeled faithfully in any reasonably sized dwelling. Only lines like Virginia & Truckee, East Broad Top or the   Buffalo Creek & Gauley had model railroad sized yards and servicing facilities. All of this is certainly true. Yet none of these is the greatest challenge when modeling the PRR. The one thing that sets the Pennsy apart from all of its competitors is the sheer amount of traffic volume.

Pennsylvania Railrpad management commissioned a study in 1945 that analyzed traffic on the Pittsburg Division over a twenty four hour period. The day chosen was April 6th, 1945, a little over a month before VE Day saw the end of the war in Europe. On that Friday sixty eight years ago, two hundred ninety eight trains operated over "the top" at Gallitzin. Of the almost three hundred trains on the east slope, one hundred one carried passengers while freight accounted for one hundred three. The mix also includes ninety one helper engines running light. Just to add to the fun, two work trains were dispatched that Friday.

These numbers are staggering. Especially when you consider all this happened within twenty or so track miles. It's doubtful that any other railroad on the globe made this many movements. Even with a four track mainline the operations department was hard pressed to meet the demand caused by this huge amount of  traffic. How do you recreate anything this monstrous in a 1:160 miniature?

If we average the numbers out, a train passed through Horseshoe Curve every 4 - 5 minutes. That's 12 or more trains each hour. To model 1 hour of operation a layout would have to be equipped with two staging yards, each with a capacity for 6 trains. The current design of Juniata, which is actually double ended open staging, provides for 10 tracks, five in each direction. Since the Allegheny Eastern is dependent on Juniata's capacity for staging trains, we can only simulate about 50 minutes of the massive daily operation.

The trouble is that things are not that simple. The actual traffic over The Hill had an eastbound bias. In the twenty four hour period analyzed in the 1945 study, Two hundred seven trains went east, but only ninety one traveled west. On the other hand, westbound traffic required eighty nine of the ninety one helper movements. Only two snappers (PRR for helpers) drifted down the west slope to return to Conemaugh. Based on these numbers a train came down the east slope every five minutes, while sixteen minutes elapsed between trains going up. To recreate an hour of operation properly staging would have to support twelve trains east bound, with four westbound. While Juniata can hold an hour of traffic moving west, the yard can only support about thirty minutes eastbound. That would mean that an operating session on the All East lasts thirty minutes before we start repeating consists or call it a day.

Since Altoona was a division point, staging freight trains would seem realistic.Trains would arrive from both directions, be broken down, classified and reassembled to be forwarded to their destinations. We might even be able to replicate some of this action and give the yard crew something to do. Keep in mind, however, that some of the freight and almost all of the passenger traffic is composed of through trains. They won't stop except for servicing, an engine or crew change, or a westbound helper assignment. So now Juniata serves as staging, but only for freight trains processed at Altoona. The ten yard tracks might easily accommodate an hours worth of such traffic. This of course begs the question...Where do I stage through trains?

What if the through trains were kept out on the mainline? The four tracks can easily accommodate a train each, two in each direction. We could consider this "roundy round" operation as orbiting the layout. The "orbits" could be synchronized with a timetable for through freight and passenger. Each time the orbiter comes around it would be considered the next train on the timetable. Trains traveling west would stop to attach a helper, with steamers taking advantage of the break to take on water. The west bound orbiter would climb the hill to Gallitzin and stop for the helper to be cut off. It would then continue west to drop down the helix and reappear at Spruce Creek as the next through train.

Once again, this might work going west, but what happens eastbound? There are three times as many trains going east. It takes a certain amount of time to circumnavigate one hundred fifty feet of mainline. Since west bound trains appear every sixteen minutes, this isn't to hard to accomplish. I cannot, however, get an eastbound freight around the layout in five minutes. At least not if I want it to stay on the tracks. It would literally be moving at sixty miles an hour. Just to seal the deal, the speed limit on The Hill is only about thirty for all trains in both directions. I have painted myself it a corner.

Fortunately there is one place on the All East capable of holding a fair number of  through trains. The helix has a track length of 30-35 feet. Staging the orbiters in the helix is a whole new ball game. The fact that it is four tracked means it has the capacity to store about twenty eight trains. Each track can store seven, each with an average length of five feet. This would allow eastbound trains to appear every five minutes without breaking a sweat (or the train). Movements west need not use the full capacity of those tracks since volume is only a third in that direction. A full  hour of operations in both directions can occur before a consist repeats itself. Working this out as part of operations would take some time to master, but it might be an effective solution. I shudder, however, in contemplating the cost of  the equipment required for all these movements.

Yet all of these movements, including the required westbound "snappers", would only represent one aspect of the challenge. The Pennsylvania Railroad did not operate with traffic conveniently spread out at equal intervals. Because of the terrain, interference in operations and other factors, there were traffic jams and long delays, particularly for freight trains. Keeping freight restricted to tracks 1 and 4 within the territory being represented exaserbates the congestion. Passenger trains used the the inner tracks, 2 and 3, to avoid the slow speeds and delays caused by the freights and helpers. Recreating through passenger service creates a scheduling problem. Most passed over the summit in the middle of the night, between 10:00 PM and 4:00 AM. I have to check the timetable to find out what percentage of the one hundred one passenger movements happened during this time.

Something to think about as the ballast strip and track are laid down.

Regards,
Frank Musick
Chief Cook and Bottle Washer