AIR2 Layout Design: Transfer Staging Yards

 On Air 1 I had four main staging yards, EAST, WEST, SOUTH, and WM. Additionally I had four smaller staging yards: Mt. Storm Branch which had three tracks, Trammel Branch which had two tracks, and Priest Valley Branch and Moss Branch  which had one track.

Most of the staging yards had more than ample trackage to hold the trains they needed, but WEST was often crowded because generally traffic eastward off layout could go into three yards, but all traffic westbound only went one place. As the layout evolved fewer and fewer tracks were needed in EAST, SOUTH, and WM, but WEST, by the nature of the layouts physical geography could not grow.

Another issue that cropped up was traffic volume. I used TTTO to control traffic. TTTO has an upward limit of the number of trains it can handle. You simply cannot move another train. On AIR 1 I planned work for each job, based on the number of cars per session each job might expect to switch. For example while the Littlerock Commercial Switcher(LRC) had 120 total car spots I might only plan to switch 40 of those in any given session.

I took each expected car spotting  on the entire layout,  and divided that number into the number of car spots in all the trains coming out of staging each session. So if I had 25 trains staged in a session, and each train came out of staging with 40 cars, that’s 1000 car spots. MTY and loaded coal hoppers represented about 400 car spots each session. Passenger trains were an interesting calculation, I model 1952 and my longest freight cars were 50’, but the vast majority were between 35’ - 40’. A 85’ passenger car took up the equivalent of two 40’ car spots, so Passenger trains could often  equal 100 car spots. And so it goes. 

In order to provide each switching district on the layout with enough work , IE., cars to switch, in a five hour session, EVERY car spot out of staging became VITAL. My upward limit on train size was roughly 45 cars. After that trains became non-clearing and posed another series of problems. 

Additionally as the layout evolved I either finished, or added more and more industries which in turn  added to the number of cars required to operate each switching district. In reality each additional car spot added roughly three cars to the total volume: one car at the industry, one car coming to the industry, and one car traveling away from the industry.

As the layout evolved we became more and more concerned with operating TTTO prototypically, and to be honest our dispatchers simply ran fewer and fewer trains. A regular five hour session usually resulted in 23 trains moved with roughly 8 additional helper moves. 

Fewer cars coming out of staging, to fill greater demand. 

Finally, and what in my opinion, was one of the greatest issues to “Through put” was differing levels of ability of crew members. One operator might be able to switch one car per minute, another,  one car every five minutes, and one operator might only accomplish an average of one car per HOUR.  This created an insurmountable back log of cars.

Al Daumann and I spent a GREAT deal of time studying this problem, along with a GREAT deal of input from other modeler/operators, and we came up with this idea. To be honest Al put this into effect a long time ago on his layout and it seemed to work. TRANSFER runs. I call them safety valve transfer runs.  If a particular switch job needs more work in a session he can call for a transfer from a “Foreign” road, in Al’s case it’s either the GN or the WP. These transfers originate from small off-layout staging tracks or yards.

If a switch job has a bottleneck of cars he can run a transfer to one of the connecting roads. If an operator is only able to accomplish a small amount of work during a session, he runs few or NO transfers. These transfers dial the intensity up or down based on the operators abilities.

To do this each switching district must have at least TWO connections to the outside world, one from the primary layout and the other or others  to these safety valve transfer staging yards. 

On AIR2 I am currently planning the following Safety Valve Connections. In the East we will interchange with the WM, C&O, and B&O. At the West end of the layout the connections will be (Currently) C&O, B&O, PRR, and NYC.

Each of these transfers will originate from a hidden staging track or tracks, all connecting to the AIR within yard limits so the Dispatcher will not be involved. 

If the Littlerock Freight House Job is crewed with a hotshot operator, who can accomplish twice as much work as the average operator, he can request a transfer from one or more of the connecting foreign roads. He can route transfers back to these roads with cars as needed.

Also in this way “The Sperandeo Rule for Transfers” can be observed, that is a transfer run in the Steam era was usually a one-way affair. If the C&O had a cut if cars for the Atlantic Inland, it brought these cars to the interchange point, dropped them and returned LIGHT. It did not take any cars from the AIR at that time. Cars for the C&O from the Atlantic Inland were brought to the C&O interchange point by an AIR crew, with an AIR locomotive and caboose.

I am now considering the creation of another job, the “Transfer Agent/Engineer” who will keep track of cars for transfer as well as run the transfers to and from each foreign staging yard. If a switch job needs additional work during a session, or has a block of cars to transfer to a foreign road he will get in touch with the Transfer Agent and those moves can be made at that time. The transfer Agent will also count cars for a foreign interchange from Littlerock (In the West) and Chatsworth (In the East) and at a certain point he will run a transfer to that road.

The entire idea is to:

1) Have the ability to move these cars without dispatcher intervention

2) Remove a significant amount of volume, IE., car spots, from the AIR TTTO main line operation

3) Tailor each job to the different ability levels of each operator.

Those of you that use TTTO for traffic control, have for encountered volume problems?

Have you encountered problems with the differing abilities of operators and how have you dealt with this?

I am REALLY VERY interested in any different opinions you have on these topics.

Thanks again.