Length of Consist - AI Confusion

[mononlaf]

I've put together a yard switching session for the Tidewater Point Rail map that comes with TRS 2006, SP 1. It works pretty well - one problem, though, and that will be another topic.

The present problem is that when I change the length of a consist, an AI driver can't get the switches set right.

I developed the session that works with a short consist - 4 coal cars with 3 oil tank cars on behind. A road engine pulls this consist into an "arrival" track that is actually a long runaround for a yard extension of the main line as it enters the yard (at Thurstan -- both these tracks are stubs). I'm using this extension as a departure track.

After uncoupling the road engine on the arrival track, a switch engine pulls up behind and takes the tankers over to a crude oil unloader, and another switch engine pulls in and takes the 4 coal cars over to the mine for loading. Both subconsists are returned to form a single consist on the departure track, and the turntable-turned road engine backs in and takes them out.

Now, all I did was increase the number of coal cars to eleven and the number of tank cars to eight. The oil switcher runs fine. But, the coal switcher (same driver, same engine) can't find his way to the mine, with eleven cars. Try after try. Same result each time, no matter what I change in the way of trackmarks. Seems to run OK up to the last turnout to the mine's stub, but then cannot throw that switch even though it has done just that with only four cars.

Maybe the oil switcher runs OK because the default position of the turnout switch to the oil unloading track is set to turn the train. In the case of the mine, the switch by default is set against the train turning into the mine. With 4 cars it can throw the switch, with 11 it can't.

The switcher backs out (pulling the coal cars) of the arrival track and runs forward (pushing the cars) to get to the mine, if that has anything to do with it.

Anybody know why the length of the consist that an engine pushes would confuse the driver? Maybe he can't see that far ahead??? A real yard would use a brakeman or somebody pushing buttons in a yard supervisor's office.

Any advice would be appreciated.

Dick

 

[atsfrr3000]

Have you checked the new consist to make sure it fits in the mine? Somehow I doubt the AI is smart enough to check consist length and stay away from tracks that are too short, but with the AI, who knows?

-Chris (tm)

 

[Bill69]

Maybe the oil switcher runs OK because the default position of the turnout switch to the oil unloading track is set to turn the train. In the case of the mine, the switch by default is set against the train turning into the mine. With 4 cars it can throw the switch, with 11 it can't.

Any advice would be appreciated.

Dick

Hi Dick,
Well can you change the default position of that switch, or does it have to default to that position for some other reason?

Bill69

 

[mononlaf]

Plenty of room at the mine for the consist - I can manually throw the switch and let the train go on in and fill up.

I wonder whether the SW1200 engine used has anything to do with it. I've got another session in which a consist with a Santa Fe road engine runs back and forth between mine and generating station. This engine backs the 11 car string into the mine and loads up just fine.

Hmmm - now I'm wondering whether I should try changing drivers - are there differences among them?

The default switch position is OK - this switch is the first along a widely spaced "ladder" of switches for the stubs serving various industries. In my session, the crude oil consist passes by before the empty hoppers come in.

Why the crude oil stub switch is default to the unloader I don't know -- there are a couple of other turnouts beyond it along the ladder.

Dick

 

[gerbils]

this may not be the problem but,

this has happened to me before. tracks came undone for no reason whatsoever. this maynot be the problem but i always try to help

 

[nwhitney]

It's possible that pushing the cars is a problem. Certain engines don't like to be coupled to the front. Rich Blake's shay gives me problems in SCS2006. Have you tried reversing the direction of the switcher so that it's coupled to the rear?
Norm

 

[Lynxfan]

I'm not absolutly sure but I think the AI driver takes control of only one junction at a time in the direction of travel. If you have another junction between the loco and the junction you want switched to get into the mine the AI can't change it until it passes the intermediate junction, by that time the last traincar may be past the juncton in question.

If this is the case try reducing the number of traincars so the consist fits between the junctions to see if this corrects the problem.

 

[stagecoach]

I'm not absolutly sure but I think the AI driver takes control of only one junction at a time in the direction of travel.quote]

The AI will look at and change more than one junction ahead, at least four if not six. Have you tried an increase of one at a time to see at which point the AI starts to get lost.

 

[mononlaf]

Thanks for the comments.

Norm may be mostly right about how the engine is hooked up to the consist.

I redesigned the session so that the road engine drops the 8 oil tankers on the main line and enters the mine running forward with the 11 coal cars. I repositioned the switch engine so that it backs into the tank cars and pulls them into the crude oil dump. In both of these cases, the engines will back their consists, setting at least 3 switches to get to the main, and will then go forwards where they are supposed to go after that -- but then we hit a have-to backup coupling that won't work. It would not work as a forward (push with the front of the engine), either.

When making up a consist after the first cars are positioned, additional cars have to be pushed in from one end or the other. We don't want an engine (or more than one) in the middle of a train.

And that's the hangup -- the road engine can't back (push its hoppers) into the departure track. The third switch back can't be thrown. I took over manually, threw the switch, then returned control to AI - it immediately threw the switch back again. The road engine is still coupled normally, back end to the first car, but now it's pushing backward, just as it did successfully to get the loaded consist back out on the main so it could run the loop and be headed frontwards down the main.

Maybe it's the signalling. The deadend rail line that I'm using for assembling the departure consist is signalled with a main line type of signal, not a yard type. With a consist sitting on the track, the signal is red. If I want to hook up with a single engine, it hesitates, but then makes the coupling (using a couple-at-trackmark command) as long as the engine that pulled the consist in has been uncoupled and taken at least one signal block ahead. But, when the engine is trying to push in a consist, it won't work.

Think I'll try taking the signal out and replacing it with a yard type.

Dick

 

[fran1]

an AI will couple to a consist with your train engine still on. uncouple it afterwards or after it has gone passed last signal before consist, remember to run your train engine forwards a little or you'll derail.

 

[mononlaf]

Thanks, fran1 - I've not been able to get the AI-driven engine to move up and couple when the road engine is still in the signal block. And, I'm not sure I understand your directions.

The situation is that both the consist (with road engine up front) and the switch engine that I want to couple at the rear to take a few cars off are AI-controlled. The switch engine has to pass a red signal before it can get to the back-end of the consist it is aiming for. As long as the road engine is within the signal block, the switch engine refuses to pass the signal. When I uncouple the road engine and move it up past the next signal, the switch engine will pass the still-red signal and couple to the rear of the consist. (This was a yard operation, so I had to put in extra signals, making for unrealistically short signal blocks.)

I have taken manual control of the switch engine and coupled it to the rear of the consist. When I do that, it wipes out the remaining AI driver commands for the road engine.

In another situation, I had a string of cars sitting on a spur to a passing track. A switch engine was coupled on behind to push it. A road engine pulled a consist up the passing track until it passed the reverse turnout to the spur. I wanted the switcher to push the string up and couple them to the back of the consist. The switch engine would not move up and do it. I got around this by uncoupling the switcher and moving it to another track that turned out from the spur. Then the road engine would back its consist up the spur and couple up under AI control. This time, I didn't move the "blocking" engine to another signal block on the same track, but moved it past a turnout to another track.

If you could give me a little more detail about your second sentence, I'd like to learn how to use switch engines to couple or uncouple a short string of cars to or from through-train consists -- which is a common task in yard operations.

Incidentally, I tried removing the signal I talked about in my last note above - did not make any difference. The same engine and driver had made the hook-up on the spur mentioned before, but now would not do it again. In the spur situation, there was only one turnout involved. In the yard, there were three turnouts, and it was the last one that would not operate.

Dick

 

[stagecoach]

You can not couple two engines onto one consist with each engine having its own commands. You need to uncouple one engine or move the driver out of the cab while the second engine does its job then move him back. The couple command will not let an engine pass a red signal if the block has an engine in it.
Two ways around this is use the "move driver to train at trackmark" command on the DLS. this will move the road engine driver to another location complete with his commands. When switch engine has finished and uncoupled use the "post message" command. road engine driver will have "wait for message and clear" command and will use the "move driver to train at trackmark" command to place him back into the road engine.

road engine arrives
move to train at trackmark
post message (driver clear)
wait for message and clear (switch complete)
move to train at trackmark

Switch engine
wait for message and clear (driver clear)
couple at trackmark (back of consist)
uncouple
post message (switch complete)
drive to trackmark

 

[mononlaf]

Thank you, stagecoach. You've taught me something here, and I will give it a try.

Dick

 

[stagecoach]

Just place a named trackmark anywhere on the same track as the consist/engine but a distance away from the consist.
You could place a piece of invisible track in the yard area with a driveable car on it and use this as the rest area for the road engine driver while the switcher does his job. In the post message it does not matter what name is used aslong as the sender and reciever get the same message.

 

[mononlaf]

Stagecoach - if you're still on, I need some more help! I've been hunting around for the post message command and the wait for message and clear command. Can't find them and can't find any rules that I identify with them. How do I find them, please? You are not talking about the Notify command or one of those messages (green envelope rule) posted to the screen are you?

Dick

 

[nwhitney]

I just searched rules with CMP, and atilabarut's postmessage is there, kuid:131986:210002, searched script and his waitformessageandclear is there, kuid2:131986:1028:2, for '06 or kuid2:131986:210006:1 for '04. Stupid motel connection is giving me problems so I can't check DLS website.
Norm

 

[mononlaf]

Arrrgh! Never thought to look for a single word. Thanks, Norm, for taking your time to do this - especially from a motel room.

Dick

 

[nwhitney]

No problem, what else do I have to do after work? Gave up going to bars, too old to feel that way in the mornings.
Norm