Update: Some great info in the comments and elsewhere, plus a new book so I posted an update to correct a lot of errors I made in this post...
A recent question on Facebook asked where they should put the control for the crossover leading to their yard, on their tower control panel, or their yard control panel. There were many answers, with many suggesting it should go on the yard board since it's related to the yard. It also seemed like this opinion was popular because it is "up to the yard master to allow a train into the yard."
I disagree, and it's not prototypical, although asking permission to enter the yard is common on a lot of model railroads.
Any switch that affects the main line is controlled by the Dispatcher, and if there is an interlocking, it's part of the interlocking. The number one priority is to keep the main line clear and lined for main line traffic. Traffic flow within the yard is under the purview of the yard master, but the train must clear the main line first. So the yard master is not in control of when trains enter the yard.
To illustrate how this works on the prototype, here's a quote from the article I posted last week:
"We came to Cedar Hill Yard. Both the conductor and the flagman went to the front platform of the caboose. At precisely the right moment they uncoupled the car from the rest of the train. The train proceeded to the westbound classification yard, while Conductor Fielding dropped off of his rolling office and took his sheaf of waybills to the yard master's office. Flagman Patchelder braked his buggy to stop on the caboose track and hung out the yellow lantern which indicated he would sleep on the car that night."
Presumably somebody else threw the iron for the caboose track...
Note that the train doesn't stop, and doesn't ask permission. They have cut off their caboose before the conductor even visits the yard master's office.
Over the years there has been a lot of (very good) guidance in designing a yard. But what I find is a bit lacking is a discussion on how to operate a yard or, more specifically. the workflow. Which means the yard gets backed up, and then you have to start asking for permission because there is no place for your train to go.
It Starts with the Arrival Track
I think this is the most important track in the yard. Many designs combine the arrival and departure track, which you can do, but you need to manage your yard very well to make it work.
Why is it the most important?
Because it gets inbound trains off of the main line.
If that's the case, what's the most important job of the yard master/crew?
Keep the arrival track clear for the next train.
Keeping that clear requires a lot of coordination. As we see in the article, the crew is on the move as they enter the yard. At the same time, the yard crews are already getting prepared for their jobs.
The hostler (who may be the same engineer as the road crew on the model), will move the road power off the train and to engine servicing.
While that is happening, a switching crew is already breaking down the train. If you can't do a flying switch to drop off your caboose, they will need to move that to the caboose track. The next move is to start pulling cars off to start classifying them.
On the model this usually means one or two at a time. This is a problem, because it's too slow. The train should be broken down in chunks.
It Really Starts with Blocking
So we have to go back a step. It actually starts earlier than the arrival track.
As we can see in the Arranged Freight Service Symbol Books (the employee freight time tables), that road freights are to be blocked. When YN-1 picks up cars in New Britain in 1951, it as the following blocks:
- Speed Witch (NE-1)
- Philadelphia Transfer (NE-1)
- Enola (NE-1)
- New London & CV (NM-4)
- Cedar Hill (which is bound for ANH-3, BO-1, BG-3, M-7, NM-4, NH-1)
By spending a few extra minutes placing the cars in these blocks, there will be less work for the yard crews at Maybrook. Note that three of the blocks will go to NE-1, but they are already in separate blocks to be added to the correct blocks within NE-1. The Cedar Hill block is one large block, to be further classified at Cedar Hill.
What about local freights?
According to New Haven rules, a Home Route Card must accompany the waybill for any indirect route car. Based on earlier rule books, it appears these were originally cards that would be stapled to the outside of the car itself. Cars destined for direct connections don't require the Home Route Card. In addition, each waybill has the route that will be used for that car. So the conductor will know the general routing of the car, and probably the connections it will use to get there.
So consider HDX-5, the New Hartford local. They will know which cars they picked up are bound for Springfield and which are bound for Cedar Hill. It's easy to block for this as you pick up cars. But I don't think they would have any more specific blocking other than a Springfield block and a Cedar Hill block. Even though there aren't any blocking instructions for the local freights, I suspect that they may have done this anyway.
Also bear in mind that these examples concern Cedar Hill which is a hump yard, so the classification process is much faster than in a flat yard. It wouldn't be unreasonable to have a couple more blocks for trains destined to a flat classification yard. They are still broad categories that will need further classification.
With the trains blocked when entering the yard, then the yard crew can pull off cuts of cars instead of ones and twos, which makes things much faster. But where to put them?
I have a Boston Freight Terminal Car Marker's Book for 1946.
It's an alphabetical listing of consignees and it tells you where they are, and what track to put cars destined for that consignee. Cars for Berger Manufacturing, Bethlehem Steel, Boston Elevated Railway, Boston Molasses Co, Boston Ordnance Depot, Boston Transit Commission, Brown-Wales Co, Joseph Burnett, and many others all go on Track No. 7. Every. Single. Day.
In this case, the Car Markers will identify each car, probably using chalk marks, for each track. Those marks will be used by the crews to classify the cars as they work.
Trains are the same way. A given track in a yard will be used to build the same train(s) every day. In general there are road freights and way (local) freights to be built. Ideally, there is a track for each, and later trains are later versions of the same train. For example, there were two Maybrook to Hartford freights daily, so the track is always for cars destined for Hartford.
You may have to share tracks. Regardless, you want to still use the same tracks for the same purpose each session. Try to design your operations like the prototype. If there are two freights bound to the same destination, say Maybrook to Hartford, you won't start building the second one until the first one is completed. In which case they can share the same track, and which train depends on what time it is during the session.
When you pull a block from the arrival track, you can ideally shove it onto the track where it belongs, as a block. If your yard lead is long enough, you can pull several blocks at a time.
This is how you get your inbound trains off of the arrival track as quickly as possible, so the next inbound train doesn't have to wait or ask permission. They simply come into the yard, at yard speed, and then hand over their paperwork to the yard master/foreman.
Blocking Outbound Trains
A track with an outbound train won't necessarily be properly blocked, since you were just shoving blocks of cars into it as you worked. Where possible, you can do some additional blocking as you break down the trains.
In addition to a switching crew breaking down inbound trains, ideally you have another crew working the other end of the yard building outbound trains. This can be efficiently done with a Departure Track and a runaround track. If you have more open track space to work with, even better. The runaround isn't really needed for running around the cars, just to have an extra track to shove things while you sort them into the proper blocks.
If the inbound switching crew doesn't have a train to break down, then they can also help block the outbound trains.
Blocking doesn't mean that you are putting the train in the exact order of all of the industries, although that can be done. In some cases, the road crew will do their own blocking to prepare for their moves. But generally, a block corresponds to a station (town).
The work in the yard is very well choreographed. While the real crews do the same job every day, we need to help our operators understand the work flow as much as they need to understand the schedule.
Manage the Flow
Of course, another major reason yards get backed up is not because there is too much work, but because there is too much work at one time. The railroad puts a lot of effort into designing a schedule to keep things moving smoothly, and this includes the traffic flow in/out of a yard.
As a general rule of thumb, I like to maintain traffic to below 50% capacity. That is, if your yard can hold 100 cars, I prefer no more than 50 cars at a time. If you start with excess capacity, then if things get behind, you'll still be able to keep the Arrival Track clear for inbound trains. It's not great if outbound trains are behind schedule, but that's a better situation than the mainline being blocked by trains that can't enter the yard. Starting the session with even less, perhaps 1/3, will also help ensure that as things get busy it won't overload the yard too much.
In addition, if you only have one Arrival Track, and one Departure Track, then you need to account for that in your scheduling.
If you must have a shared Arrival/Departure Track, then try to block as much of the outbound train prior to moving it to the Departure Track, and move it shortly before its scheduled departure time. Then you'll only need to add a caboose and power and get clearance to leave, tying up the Arrival Track for as short a period as possible.
The Dispatcher, if you have one, needs to manage the flow as well. In eras where passenger trains were First Class, freights could find themselves parked on a siding for a long time. On the model this approach is often necessary to manage inbound yard traffic.
Your train crews have an important job in this regard as well. They need to stay on schedule as best they can. That includes not running too fast in addition to not running late. Having them block their trains as they pick up cars can help slow them down a bit. It's not uncommon for freight operators to try to get ahead of various other trains and rush to get their job done.
It's not uncommon on a larger layout for things to start to get bunched up, and once they do it's hard to resolve since each late train starts to impact other trains scheduled later. This can occur just as easily because too many trains are arriving early as late.
It's also important to give the crews, especially the yard crews, space to work. I have workspaces in several places around the layout so crews won't need to be putting paperwork on top of the layout. While I understand the appeal of leaning waybills on their cars, it generally means adjacent tracks are unusable until the cards are moved.
Splitting crews between inbound and outbound switching can help as well, since they are focused on narrower portions of the job. The inbound crew should be focused on classifying the cars into the correct tracks, and the outbound crew can focus on properly blocking one outbound train at a time. Even if it's the same crew doing both jobs, breaking the work flow down in this manner can help operators keep things organized.
Simply adding blocked inbound trains and a rule that the Arrival Track must be cleared as soon as possible would greatly improve the efficiency of most model railroad yards. And it would largely eliminate the non-prototypical approach of asking the yard master for permission to enter the yard.