Just curious ...

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wombat457

Well-Known Member
Staff member
Most, if not all freight lines are single track; therefore, can you run two trains in opposite directions on a single track? Obviously on a DCC layout.

I suspect the answer is yes but want to make sure. The answer will help me decide whether or not to build a double main line or single main with passing tracks.

If the answer is yes, is it just a matter of placing the engines in the appropriate directions or do you need to do something else?
 

Bruette

Well-Known Member
Tony maybe because I live in the northeast corridor, but all the main lines I am aware of near me are double tracks or more, most are more.

To answer your question all you need is a passing siding to run trains in opposite directions on a single track. No trouble in DCC in DC you would have to electrically isolate the siding from the main.
 

tootnkumin

Well-Known Member
Staff member
As Louis has said, no problems with DCC, engine don't rely on the track's polarity to go in the direction the controller indicates on the same track. Most of the AMRA clubs layout is single track with passing sidings. We run to a rule. Long trains that won't fit in a siding run in only one direction (which can change per operating session, generally decided by who sets up the first long train) and short trains that will fit, can run in either direction, because they can be passed by either long or short trains.
 

wombat457

Well-Known Member
Staff member
Thanks guys, I thought it could be done but had this nagging doubt for some reason.
 

Iron Horseman

Well-Known Member
Most, if not all freight lines are single track; therefore, can you run two trains in opposite directions on a single track? Obviously on a DCC layout.

I suspect the answer is yes but want to make sure. The answer will help me decide whether or not to build a double main line or single main with passing tracks.

If the answer is yes, is it just a matter of placing the engines in the appropriate directions or do you need to do something else?
The museum layout was designed specifically as a single track main line to increase the operating interest. The owner figured with a double track main line operating would be just running trains in loops varying the speed so as not to run into the train in front.

The general rule of thumb for a single track main line, on a loop, is that the line can handle a maximum of 1 train per passing siding. This assumes one wants all the trains moving. Depending on the size of layout I usually use the formula of #number of normally desired trains + 2 = number of passing sidings. That way occasionally another train can be added to the mix, or one can do overtakes (fast train passing a slower one). On small layouts often one has to just go with 1 train to 1 passing siding cause there just isn't enough room. On the other hand if one doesn't mind one train always stopped, the rule changes. If on goes to the extreme and says only 1 train needs to move at a time, the formula is trains = # passing sidings * 2 - 1. Without the minus 1 a train could always only return to the track from which it came.

On a point-to-point type system the rule of max trains changes to 2 trains per passing siding. That is because the trains run off the "end" of the layout instead of being feed back into it. The yard on each end acts as a sink that can theoretically take and produce an unlimited number of trains. A train in a siding can always go to the yard.
 
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montanan

Whiskey Merchant
I have a couple of passing sidings on my layout. The length of the passing sidings were determined by the length of a train that a single locomotive could comfortably pull up a 2% grade which worked out to be an average of 15 cars. As it ended up, I didn't really need them as I only run one train at a time. I am a lone operator and at my age, one train at a time is enough. I have had visitors over and have had two trains operating, usually a through train and one switching industries. The switcher would use the passing siding and would have to keep the main line clear when a through train approached.

My model railroad friend in Missouri has a huge home layout that occupies an entire basement. He estimates that there is about 9 scale miles of main line alone. The main line is mostly a single track with a couple of sections of double main line. Operating sessions can get quite interesting. On his layout passing sidings are about 30 cars long. When a meet comes, the shorter train will hit the passing siding to let longer trains pass. With a good dispatcher, he can have over 20 trains operating at the same time, including yard switchers and local freight trains doing their switching duties. He has operating signals throughout the entire layout and operators best pay attention to them as well as listening to the dispatcher. Operating sessions are a lot of fun, but are also quite a bit of work.

We are hoping to get down there later this summer if we can get out remodeling projects completed. We try to coordinate visits with the NASCAR schedule and kill 2 birds with one stone.
 

wombat457

Well-Known Member
Staff member
More to having a single line than I thought in terms of what needs to be taken into consideration. One of the things I did not contemplate was the length of trains in relation to the passing siding and in relation to the layout size over all. I think I will be able to run "up to" 15 cars plus engine on my new layout BUT the design of the layout may not lend itself to having a siding that would accommodate my largest train. Oh well, it was just a thought.
 
... BUT the design of the layout may not lend itself to having a siding that would accommodate my largest train. Oh well, it was just a thought.

Your passing siding does not have to accommodate your longest train, when you have opposing trains the siding only has to be able to accommodate the shorter of the two trains.
 

Iron Horseman

Well-Known Member
Your passing siding does not have to accommodate your longest train, when you have opposing trains the siding only has to be able to accommodate the shorter of the two trains.
Yes what he said. The longer train that won't fit can always be given the right of way so the others have to get out of the way on the sidings. The problem would be meeting of two trains that are longer than the passing siding. Then they have to perform a maneuver called a saw-by. Can be quite interesting if it doesn't happen too often.
 

tootnkumin

Well-Known Member
Staff member
Interesting manoeuvre. Have to try it at the club. That'll cause a hue and cry from the ones backed up behind.
 

jdetray

Well-Known Member
In the late 1960's and early 1970's I rode the famous "Wabash Cannonball" passenger train to and from college many times -- Mattoon IL to Montpelier OH. In central Indiana, there must have been a section of single track mainline because the Cannonball occasionally pulled onto a siding to allow a long freight to pass in the opposite direction. I always assumed that the freight was too long to fit on the siding. Otherwise the passenger train would normally take precedence, no?

I was honored to ride on one of the last regular runs of the "Wabash Cannonball." Good memories, even though the accommodations were pretty shabby in those last days.

- Jeff
 




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