Yards--freight and passenger
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Ten tips to designing better yards
One of the most often modeled layout design elements is the classification yard. Nearly everyone has one on their layout, whether it's used simply for car storage or as an actual operating tool. Unfortunately, many of them don't work very well. Common mistakes are made over and over again by beginner and intermediate modelers lacking good yard design experience, and poor designs are often published by the hobby press, aggravating the problem. Finally, the 'secrets' of good yard design are sometimes difficult to uncover, because the good nuggets of information appear in wildly different places and can be difficult to collect by the modeler not deeply interested in the subject. To help out folks interested in designing good, working yards, I've come up with a list of ten suggested elements that will help anyone design a better yard for themselves. I can't take credit for these ideas, for the most part, they aren't mine. They are a consolidation of ideas from leading modelers in our hobby and of other modelers I've spoken or communicated with, or ideas I've heard about fourth or fifth-hand. The sheer number of persons responsible is far too large to acknowledge everyone, so I'll just say thanks to the community at large for sharing this knowledge with me. And now, I'll share it with you. So without further delay, my Ten Elements of Model Railroad Yard Design:
1: Don't Foul The Main
Most modelers would not usually consider the main line as a part of the yard, but in reality it is the most important track in the yard. The main line is the artery that carries the life blood of the railroad, passengers and freight. And just as in the arteries of a living thing, if the mains become obstructed it quickly causes major problems to the entire system. The prototype railroads we model go to great lengths to keep their mains clear, and so should we. Nothing brings a railroad to a halt faster than the local yard switcher occupying the main to do it's work. Therefore when beginning the design of any yard, we consider this first element before any other design rule.
Ideally, the main line should have a maximum of two turnouts connected to it, one at each end of the primary Arrival / Departure track (see element # 4). The only time these turnouts should be in the reversed aspect is when trains are either entering or leaving the yard. At all other times they should be in the normal position, allowing for regular traffic to bypass the yard completely without interfering with the work being done and vice-versa. If your plan currently allows the local switcher to foul the main while switching, or uses the main as a yard lead, you need to seriously re-evaluate your design at this point.
Of course, there are exceptions to every rule, and this is no different: This rule may not apply to certain applications, such as small yards / terminals on the most lightly traveled branch lines, or simple storage yards on small layouts. A good rule of thumb to follow is if the switching train is isolated, or space limitations are extremely tight, the main track may be used as a yard lead. Otherwise, the main line should remain inviolate.
2: Provide A Dedicated Lead Track
After the main line, the most important track in the yard is the lead track. The lead is the backbone of the yard, it is the track all others either connect to or branch from. The lead should allow the switching crew complete access to all places in the yard with a minimum of effort. Because the switching crew uses the lead to "drill", or move railcars in and out of the body tracks, the lead must be as long, or longer, than the longest yard body track. This prevents the switcher from having to "double" a cut of cars, or move 1/2 the contents of one track at a time, to another. Double-ended yard designs (with ladder tracks on either end of the body of the yard) should have dedicated leads on both sides to allow the yard to be worked from both ends simultaneously, even if one of the leads is a 'minor' lead without full yard access or length.
Curiously, many published designs in the hobby press and many layout plan books often omit the yard lead, as though it were not important at all; or provide for a lead so inadequate as to be practically useless. It bears pointing out that without a dedicated lead of adequate length, the body tracks of the yard cannot be worked without fouling the main (assuming the main is used to drill the yard) which of course violates the first element above. If you are adapting a plan from a book and it does not include a yard lead, you should evaluate the design and make changes where appropriate to ensure a proper lead is included. This may involve serious changes to the plan, but will be well worth it when the layout is built and operated.
If it seems difficult to find space for the lead, remember that it can be disguised as a branch line or other kind of track if desired. As an example, Tony Koester's Allegheny Midland disguises the lead to Sunrise Yard as a branch line that parallels the main and eventually breaks away and wanders off the edge of the benchwork. But its true purpose is as a yard lead, and that should always be foremost in the designer's mind. A lead for a small yard could be disguised as an industrial track, for instance, serving an industry that no longer uses rail service (and therefore would always be clear). A little imagination goes a long way.
As we will see in the following elements, there is far more in a yard than just the body tracks. Under ideal conditions, the yard switcher should be able to access all the major tracks in the yard from the lead in no more than two moves, and as many as possible in a single move. We'll see what other elements radiate from the lead as we continue.
3: Don't Foul The Yard Lead
Now that we've cleared the main and given the switcher a dedicated track of it's own to work from, we have to ensure the switching crew can do their job no matter what kind of lunacy is going on around them. Yard switching takes time, and when running under a fast clock reaction time becomes critical. Even short interruptions of the switching crew can have a serious effect on the whole railroad. For instance, recurring delays caused by road power crossing the lead on its way to servicing can quickly impact the pace of the yard crew, delaying other departures and arrivals. Without question, then, it is important to ensure the yard lead is free of potential obstructions at all times.
An ideal yard design calls for a yard lead with the fewest possible obstructions along with the greatest possible access to the yard as a whole. While designing or evaluating the yard design, avoid including crossovers, diamonds or other trackage arrangements that interfere with or cross the yard lead. Also avoid industrial spurs or other tracks off the lead that may require servicing by trains other than the yard switcher, such as coaling towers or sand houses. The yard lead should be as isolated from regular traffic as possible, allowing the switch crew to continue classifying cars indefinitely regardless of the comings or goings of other trains.
Another thing to avoid is the temptation to use the lead for moving trains in and out of the yard by connecting it to the main at the far end. It seems like a natural thing for trains to arrive and depart via this track since it leads directly into the yard, but it is a trap that will paralyze the yard for long periods of time. Keep the lead isolated and the domain of the yard switcher only. Handling trains between the yard and the main will be covered in the next element. It is OK to have the lead and the main joined at the far end (if it occurs naturally), as long as the purpose of the connection isn't perverted.
Yards with active tracks that cut across the lead will constantly be delayed and in turmoil. But it can't always be avoided, especially in smaller designs. If the designer starts off with this element in mind, it will help avoid situations where this becomes necessary and minimize the impact of those instances that can't be helped.
4: Use Arrival / Departure Tracks
Question: According to the first three elements, we can't use the main for anything (except mainline trains), and we can't use the yard lead to move trains in and out of the yard. So, how do we get trains off the main and into the yard, and vice-versa? The answer is to include one or more special 'transition' tracks between the main and the yard called 'arrival / departure' tracks, or A/D tracks.
A/D tracks are sidings off the main with a connection to the base of the yard lead, where trains are stored -- temporarily -- while they are broken down or built up. The yard switcher should be able to cross over easily from the lead, grab a cut of cars from a recently arrived train (or the whole train once road power has been cut off) from the A/D track and pull it directly onto the lead to begin classifying it. Or, the switcher should be able to pull a cut from the yard body and kick it into the A/D track. Each of the above maneuvers should be possible in just two moves -- in and out.
A/D tracks should be as long or longer than the longest passing siding, or maximum expected train length. A/D tracks should be easily and directly accessed by the lard lead at its base, and I recommend they also should have an escape to engine service (Even if it's just a short temporary escape spur) that does not foul the yard lead. A/D tracks should be kept clear at all times, except when breaking down or building up a train that has just arrived or is about to depart. Cars should never be left on the A/D track indefinitely because this effectively blocks the access points into and out of your yard, immediately rendering it ineffective.
5: Provide A Caboose Track
Whether it's a double-ended siding or a stub spur, if you model the period before end-of-train devices you need to have a place to store cabooses out of the way while classifying trains. It has to be handy to the switching crew because they will be moving cabooses in and out of that track often. Because it is used heavily, the Caboose track is often located off either the yard ladder, the yard lead or one of the A/D tracks. A siding that parallels the yard ladder track, connecting to the ladder itself or the lead on one end and the end of the ladder on the far end is often a good choice for saving space. It's good to add an extra inch or two between the caboose track and the ladder track for man-on-ground clearance.
Another good location is off the primary A/D track (where you spend a lot of time building or breaking a train anyway), but any location easy to get to while working a train on the A/D track will work. A scenery tip: Locate the yard office nearby the caboose track so the conductors don't have to walk too far. The caboose track also happens to be a great place to display all your caboose models too.
If you are a modeler concerned with prototype operating accuracy, I suggest trying to design in a double-ended siding. On many railroads conductors and crews were permanently assigned to a particular caboose, and these cabooses generally left the yard in about the same order they arrived. With a double-ended siding, you can kick cabooses into the track from one end and pull them off the other end for departing trains easily, simulating this common prototype practice easily. This is very hard to model with a stub spur.
6: Provide A Run-around
Somewhere off the lead, the ladder track or an exterior yard body track, be sure to provide a short siding or set of facing crossovers to an adjacent track, creating a run-around. a run-around is one of the most useful trackage arrangements in the yard, allowing the yard switcher get around to the other end of a car or caboose. If planned properly it doesn't even have to take up any extra space. A run-around is necessary because certain switching actions become difficult, or impossible, without it. For instance, it becomes very difficult for a switcher to tack a caboose onto the back of a freight train departing in the direction opposite the orientation of the yard. And not only is having the engineer of a freight train back his whole train up to pick up a caboose highly unprototypical, it's a dangerous practice to follow with easily-tipped coal or wood-fired stoves in the caboose.
The run-around should be long enough to allow the switcher to run completely around one of your longest cars (a passenger car, or auto-rack). More length is better, though over 3 regular car lengths is probably more length than necessary. More than one run-around track located in different places is even better yet. Close proximity to the base of the lead is an important consideration.
Run-arounds are also highly useful on smaller layouts, particularly if there are one or more facing point turnouts on local sidings that must be served by the yard switcher. Often the yard crew may switch a local industry like this, unsuitable to be served by a regular local, during quiet periods in the main yard.
7: Provide Auxiliary Yard Tracks
Auxiliary tracks within the yard limits are incredibly important, and provide a great deal of operating potential and fun. It's scope is a subject in itself, and will therefore be covered separately in the section, Auxiliary Yards.
8: Provide Engine Services
When you properly operate a classification yard, you quickly find that unless you find a place for them to lay over, a lot of engines spend a lot of time in your yard taking up space. Whether they are on standby waiting for the next train to be called or just being serviced, you need a place to keep them, like a caboose track, out of the way until you need them.
Your engine service tracks should allow a direct escape from and to the A/D tracks so locomotives can get away or move in quickly and easily, without fouling either the main line or the yard lead. These tracks, often called service tracks or leads, can be dressed up with water towers or water columns, coal towers, sand towers and houses, diesel fuel racks, ash pits and cinder conveyors, etc. However they are dressed up, remember their primary purpose is as a place to store excess motive power until it is needed by a departing train..
It is not necessary to include large, space-gobbling scenic items as a diesel house, roundhouse, or car shops. These large buildings can be implied by having the tracks run off the edge of the layout to where the building should be (see Tony Koesters' Sunrise Yard plan in MRP '96), or by using flats against the backdrop to suggest their presence, or truncating them to save space (Bill Darnaby's Maumee Roundhouse, August '96 Model Railroader). A turntable is not absolutely necessary either, unless your model roster includes a lot of steam power.
If you model more than one service track, concentrate the services along one of the tracks -- this will be the inbound lead. Locomotives are generally serviced as they arrive at a yard, not as they are leaving, with the exception of sand service in some places.
9: Don't Overcrowd The Yard
All yards have a certain threshold number of railcars they can hold and continue to function properly. Go beyond this threshold amount and the yard quickly clogs, making it very difficult to work with. You will usually find that the better the yard design, the higher the ratio of cars per square foot of yard will be. But sooner or later, any yard will become clogged if enough cars are crammed into it. The trick to good yard operation is to plan the yard to handle the expected traffic before it is built, so problems are avoided in the first place.
Layout designers should plan their yards to be able to handle the expected number of railcars per hour passing though, plus storage, and plus extra room to continue working the yard during heavy traffic periods. A good rule of thumb would be to figure out the number of railcars expected through per hour, plus storage, and add between 30 - 40 % more to that amount. Then design the body of the yard to hold this number of cars. If the yard can't be made that large, reduce the number of trains or the number of cars per train until the threshold amount is reached. Smaller percentages reduce the threshold
Now, all model railroads have busy times where several trains arrive at once and the yard crew is overwhelmed for a short time. But if the yard seems constantly clogged even during slower times, the modeler probably has too many railcars on the layout. If clogging becomes a constant thing instead of occasional, the modeler probably has too many cars on the layout for the yard to support. Pull a few cars off at a time until things start running more smoothly. A clogged yard quickly becomes a bottleneck in the entire system, bringing the railroad to a standstill and frustrating everyone involved.
10: Make It Easy To Run
Lets say the designer has followed all the above elements and designed a great yard. Even the best yard plan isn't worth beans if no one can figure out how to operate it once it is made real. The designer owes it to himself and the others who will operate the railroad to give some thought to making the model-human interface simple and easy to understand. Here are some things the designer can do to really help operability: Provide a large, easy to read schematic control panel with color-coded track lines to differentiate what each track is. For instance, make the body tracks white, the yard lead red, the A/D tracks green, etc.. Label anything that might be unclear or vague. Physically separate adjacent tracks with different purposes to emphasize their difference. If there is not adequate space for this type of panel, an easily visible reference sheet should be available to explain the routing scheme and the controls on the panel
Keep the mechanical complexity down. Wherever you have a crossover where two turnouts always operate together, control them with one toggle switch. Use a diode-matrix panel or similar control structure to automatically throw turnouts in a yard ladder for a particular arrangement. "But isn't that complex?" you ask? Yes, but it makes the yard crew's life easier during a session, so it counts as a simplicity plus.
Provide a handout with a schematic diagram of the yard and a line or two describing the different functions of each track to new operators. It will help them get familiar with the routine and up and running in less time than if they had to puzzle it out for themselves. You can also distribute this handout to visitors, allowing them to gain an insight into how the operation really works.
Provide a lineup schedule to the yard crew describing the types of trains arriving and departing during the session, approximately the time they come and go, and what type of freight loads or passenger equipment they drop off or pick up. This will help the yard crew organize their work, and be able to properly block the cars in most trains. A properly blocked train is easier for the road crew to run, and gets it's work done faster.
Sometimes You Have to Break the Rules
Earlier, we established rule # 1, Don't Foul the Main, and Rule # 3, Don't foul the Yard Lead. Two good rules. Now, we're going to explain why sometimes you have to break that rule.
True enough, it is best to avoid crossing either the main or the yard lead . But the fact is, it can be very difficult to design an escape to engine service from a set of arrival / departure tracks without crossing either the main or the yard lead. Since the ladder track and mainline usually bracket the A/D tracks on one end, the obvious answer is to place services on the opposite end of the yard. But, most of us don't have the room for an engine service area, plus the yard length, plus the yard lead length. It's much more efficient for us to place services adjacent to the yard lead, freeing the space at the other end. Unfortunately, that requires a crossing of the main or the lead to get locomotives in and out of the service area. Prototype RR's often found it necessary to do this, and often for similar reasons.
Is it better to cross the main, or the lead? It depends on how busy each track is. In most cases where an active classification yard is modeled, it's probably best to place the service area across the main, since traffic on the main is probably lighter. For a storage or coach yard with less activity, cross the yard lead to service locomotives and leave the mainline alone. Either way, you should know going into this it will have an effect on train movements through the area, and as noted earlier it may cause serious delays if used extensively on a busy mainline or yard.
If you elect to cross the main, you'll need to enforce Rule 93 (movements within yard limits) with regard to trains passing by on the mainline. Since a light engine movement to or from service might be occurring as the train enters yard limits, Trains can only proceed through at restricted speed (slow), looking out ahead and prepared to stop in half the visible distance for any reason (including obstructions or turnouts thrown against their correct route). Of course, by forcing trains to move slowly through the area, it helps stretch the apparent mainline, so there is a tradeoff in the positive direction as well.
General thoughts on the smaller plan
I realize that it takes a fair to good-sized yard to fully implement many of these concepts. The modeler with a smaller space, however, still has much to gain by using these criteria to help design the small yard. Perhaps, as an example, there isn't room for a full length caboose track. But an extra 18" track off the end of the ladder track will hold 2, maybe 3 cabooses, and the inclusion of a short run-around, possibly also used for a nearby industrial switching area, lets you do quite a lot of operating within a little space. The smaller plan doesn't need 2 or 3 A/D tracks, having one that also functions as an occasional siding off the main line will work, even if it's not ideal.
The point is that the design elements are valid no matter the size. A little compromise here and there may be necessary, and some elements may need to perform two or more compatible duties. But no matter the size, considering the elements above will guide the designer to a workable plan even if it can't hold everything desirable.
About this content:
Original author: Craig Bisgeier. Last revised in 1996.
This LDSIG article is ©1996 by Craig Bisgeier