Keep Trains a fixed distance apart

CLM posted:

I've got some large loops I'm building around the outside of my layout - probably on the order of 100 feet long by the time all is said and done. 

How can I have 2 (or 3 or 4) trains run in each loop? I would like the trains to maintain a fixed distance apart so that they can run around without collisions and without human intervention. 

The only solution I've come up with is multiple Lionel Sensor tracks and some custom software controlling speed via Legacy commands.

Is there anything turnkey out there, or any solutions others have used? 

Cheers,
Chris

we run multiple trains on our club layout all the time.

you did not state what kind of trains you will be running.

but lionel trains with odyssey runs pretty must at the speed you set.

Your post sounds as though you want these trains to run hands off.  I do not know of anything that will do what you want that is manufactured "turnkey" to maintain the gaps. We have run multiple trains on my Flyer layout but this being done with multiple operators.

Ray

https://youtu.be/6AUB7D8lXTA

Azatrax has a turnkey system that you can purchase-Run two trains on one track

Four trains in 100 feet will be pretty tight spacing.  Our club layout main loop is a multi turn affair with around 400 feet of track, when we get four or five people running, it takes constant vigilance to keep from having a collision.  Having four trains of any size at all on a 100 foot loop will be some tight timing. The system Carl points out is for conventional running.  Also, in a block system such as it depicted in that link, the trains start and stop typically to maintain spacing.

The absolute simplest solution if they are all Legacy locomotives is to build a train and then now they all move in unison.

As for me, my biggest loop is just over 36 feet, and I've run 3 trains on it at once, each pulling between 6-12 cars.  As they were all Legacy locomotives, I just used the preset speeds.  I got one going, then started the second at the same speed setting, then the third. And as I'm there, I keep on eye on it, and if one seemed to creep closer to another, I'd adjust the speed by one step and watch, and adjust again if needed.  It's quite fun to do.

I'm happy to run either conventional or Legacy engines on the loops. I've been acquiring a number of the LionMaster series of engines recently, and would be more than happy to run those. 

Ideally this would be fairly hands-off, so that I can just have the trains running around the outer loop while the majority of attention is spent to running trains on the primary layout. I'm not clear yet (I need to try) how consistent the Odyssey speeds are across trains - that is, how easy is it to match a 4-6-6-4 Challenger to a SD-90 or similar? I'm planning on having a 2 helixes in the loops, with a high-bridge between them, so that I can walk into my layout without having to crawl in. Clearly pulling power up the incline will also be a variable. 

I think my best bet remains the Legacy with 4 of the Sensor Tracks per loop. A bit of custom software seems like it would be easy enough to write, given that the Legacy protocols are documented and I'm a software engineer by profession. 

I do that all the time on my layout.  It is easy with DCS.  I'm sure it can be done with the Lionel Legacy system as well, but I know first hand that operating more than one train on the same loops works great with DCS.

Maybe the electronic wizards will develop a radar system. That's what is planned for automobiles to cut the rate of rear-end collisions. Expensive complicated technology for inattentive drivers in the nanny state.

For railroad applications, use an operating block signal system. Or get an operator like Sinclair who enjoys managing multiple trains.

Mr Union Pacific posted:

I do that all the time on my layout.  It is easy with DCS.  I'm sure it can be done with the Lionel Legacy system as well, but I know first hand that operating more than one train on the same loops works great with DCS.

I'd keep in mind that all it takes is one of the running units to develop some issue where it stops and you get the collision we keep talking about.   Legacy will maintain set speeds as well as DCS, that's not a determining factor.

Ok, GUNRUNNERJOHN is right, I had had that happen before.  I couldn't hit the emergency stop button fast enough.  Fortunately nothing was hurt in the accident.

This gets into the 'somewhat to fairly complex' realm, but here is my solution.  

Affix an RFID tag to each locomotive to each engine so that it can be uniquely identified by sensors around the track.  (The IR and sensor tracks could be used but I do not presently know how to decode the information they provide.)  I might also place RFID tags on the last car of each train so that the system can confirm that the train has fully passed and that none of the cars have become uncoupled and left on the track.  

From there you can program a micro-controller or computer to monitor the sensors.  it could be programed to keep track of the time between the end of one train passing a sensor and the engine of the next, then if the second (or 3rd or 4th) engine is following to close if can send a command to the TMCC/Legacy base to slow down the 2nd engine by a speed step or two.  

While this is fairly simple in the world of hobby electronics, it is rather complex by the standards of what most folks here are want to do.  

JGL

I do it all the time with DCS since you can set the scale mile per hour.  But that is not to say that you can completely ignore them.  An attentive engineer is always prudent.

Dennis

I don't care what system you run, DCS or Legacy, sooner or later one engine will catch up to the other.  Without some kind of outside monitoring the tolerances in these systems and the engines are not tight enough to stay exactly at the same speed over the course of time.  Without some master "clock" syncing and knowing where all the players are at any given time there will be collisions.

Some engines track better than others and it may take some time but an outside system or control with tracking ability will be required.  Making them all a (TR) train will not help.  The lack of tight tolerances and a sync'd system will eventual have an engine catch up or slow down. 

As usual, Marty speaks the truth.  While I've run at modular shows with three trains on a track loop of around 120 feet, usually within 10-15 minutes, I'm tweaking one to maintain the spacing.  This is with all of the engines having cruise control.  DCS or TMCC/Legacy makes no difference, you still have to have a hand on the throttle periodically.

I concur, just like the real thing, if you have more than one running on the same loop...don't leave the room.  Through past experience I have learned that leaving running trains unattended, bad things can happen.

This is why I leave the couplers open on the ends of my trains, and all steam locomotives get the claw installed on the front (Where it is possible.).  So if one does happen to catch up, they'll just couple, and now it's a trains with distributed power (Ignore that caboose in the middle.).  With my Legacy system to Lionel for repair, I had to run using my Cab-1 and TMCC base last night.  After getting my heavy Mikado and 10 Wheeler going, they went round and round for almost an hour without getting close.  It's so relaxing to have a couple steamers going at once.

As for the OP's helices, if they are Legacy, then keep the cruse on and they'll go uphill, downhill, straight, and curves all at the same speed.  If it were me, I would limit that loop to only command (Legacy and or DCS) locomotives of the same system and set them at the same speed and just make sure to check on them every once in a while, say like 30 min or so, and you'll be fine without needing extra fancy things to space them out.

I'm not sure how the sensor tracks could help you unless you write software that keeps track of the time stamp of when a locomotive passes over it, and then the time stamp of all the others in the loop as well as the time to make a loop, then calculates the train speeds and notices when a train is getting closer to the next, at which point it'll have to know which sensor track the faster train will go over next, and when, and then it'll program the sensor track just before that faster train gets to it so that it gets told to go slower.  And the software would have to have speed curves for each locomotive to know what speed to set it too, or it'll just keep noting and adjusting the speed with every other sensor track pass.  Not saying it can't be done, only that it'll require a very good understanding of programming, and having the Legacy command set which Lionel hasn't released (They've only released the TMCC command set.).

Thanks Sinclair. 

I am leaning towards all Legacy around the outer loops - that seems pretty straightforward and just simplifies things. 

Software for me is the easy part - assuming my kids can leave me alone for a few hours to crack open the Legacy API's and write some code. So far my experience with Legacy has been turnkey - using the big controller and an iPad. Taking that to the next level will be fun. 

I did like the suggestion someone had of RFID. Putting a few readers in the room and tracking position that way seems like it would be pretty practical. The sensor tracks will probably be easier, as it seems pretty turnkey. 

Cheers,
Chris

Sinclair, for what it's worth, Lionel released the Legacy protocol some time around the release of the LCS system.  it can be found on Lionel's website, here:  

http://www.lionel.com/lcs/reso...tocol-Spec-v1.22.pdf

I have no legacy equipment thus have not played with the spec at all, but it seems almost as straight forward as the TMCC protocol.  

Also, needing to have a detailed speed table is unnecessary.  You can use 'dumb logic' to simply issue the next faster or slower speed to the engines, after using trial and error to determine what the optimal starting speed for each engine should be.  

Again, I tend to like the idea of RFID, as it allows for a second, 'end of train has passed' check point, insuring that if a couple cars get left behind somewhere the engines will all come to a stop.  I also like RFID because, compared to sensor tracks, it is dirt cheap.  You can likely purchase all of the parts needed to use RFID for the cost of a single sensor track.  

JGL

My guess is the RFID might be a bit easier, though either option can certainly be done.