Automatic stopping section for staging

[Cajonpassfan]

Recently, I was fortunate enough to be invited to operate on Gary Peterson's layout in Salt Lake City. The layout supports about 20 operators. It's a busy railroad, with a semi-hidden off-stage staging yard. At the end of the run, trains enter the hidden staging yard at restricted speed and stop automatically at a predetermined spot. This helps make efficient use of the hidden  trackage and prevents people not familiar with the layout running past the fouling points or leaving their hind end hanging out on the main. And it enables the train crews to get out of a busy congested isle space....no need to hang around blocking access for others. I like it.

I'd like to rig something similar for my staging, but want to keep it simple. The simplest form of course is a dead section at the end of the one-way staging yard, but that only works with single locomotives, or units wired together, and I run with multiple units and doubleheaders. It seems I need a detector of some sort that triggers the stopping section. There are 14 tracks that need this, and I do want to keep it as simple as possible. Is anything like this available commercially? Oh yes, I use NCE DCC. Photo below.

Thoughts and ideas appreciated!
Otto K.

[wcfn100]

As long as the sensor gives enough room for the train to stop and the whole train is on the siding when the sensor is tripped, you can have as many locomotives you want anywhere in the train without having to wire them together in any way.

Jason

[peteski]

The easiest would be a gapped end section, slightly longer than any of the loco consists with a manual toggle switch connecting the gapped rail to the live rail. But that will not work in multi-unit lash-ups. When each loco enters the dead it no longer runs so the trailing units are pushing the dead locos. Not really workable (especially with 3 or more locos).

So any solution will require some sort of (electronic) detector and a relay to cut the power after all the locos enter the stopping section. Then you also will need a manual way to restore the power when backing up. 

[jagged ben]

Did you ask Gary Peterson how he did it?   

How I would might do it simply:  The sensor trips a relay that turns off track power to the whole staging track.  I would try to do this with a normally closed relay.  A toggle switch can be used to disconnect the coil input and thus override the sensor in order to move the train back out of staging.   The operator flips the toggle for the desired track and then flips it back when the train is clear of the staging track.

 This solution would work with an optical sensor but you'd have the disadvantage of having to wait for the entire train to clear before flipping the toggle switch back.  A current sensor might be a little more expensive to set up, but it would have advantage of only having to wait for the locos to clear, if you're not using detector wheelsets.

How I might do it less simply: control the relay through a JMRI output and use current sensors to input info to JMRI, write up some logix that would know when to switch the relay, and dispatch trains out of staging from the computer and/or possibly some additional fascia buttons.

[Cajonpassfan]

Yes Ben, I did ask, LOL. Didn't like the answer. Gary is using remotely dispatched CTC running on JMRI I believe. I'm not going there... I need to simplify my hobby (and life), hence my original question.

Yes, some kind of a switch, mechanical, electro-mechanical or electronic is needed to kill the power to the "stopping section" (I'd rather not kill the entire track between heading-in and heeding-out switches because I may need to get to the back of the train with a switcher to swap cars or bring in two shorter trains in tandem; the following section would not be stopped automatically. Also, there will be no "pusher" engines entering the staging yard; these are trains coming off the hill). So I see the "stopping section" to be no more than 18 to 24".

The sensor to trigger the killswitch can be optical, electronic, or even mechanical; again simple is the key here. Good point about having to wait for the entire train to clear on departure...that would not be optimal. I want the visiting engineers to take their clearance card and go, and enjoy the experience rather than worrying about some obscure switch.

Well, maybe we'll get some other ideas.
Thanks guys!
Otto K.

[peteski]

Even with a simple kill switch, with DCC you will have to remember to set the throttle of that consist to speed step 0 so the train does not start running forward as soon as the power returns to the track. This is one of the scenarios where this would be much easier to accomplish and control in DC.

You might find out that Gary's (complex) solution ends up being the optimal solution.

[Cajonpassfan]

Even with a simple kill switch, with DCC you will have to remember to set the throttle of that consist to speed step 0 so the train does not start running forward as soon as the power returns to the track. This is one of the scenarios where this would be much easier to accomplish and control in DC.

You might find out that Gary's (complex) solution ends up being the optimal solution.

Pete, good point about zeroing out the throttle at the end of the run. My plan is for the road crews to hand their cab (and papers) to the Barstow based trainmaster at the end of the run and it will be his job is to make sure the cabs are zeroed out. At least with NCE, they don't have to be "dispatched"

I still think there is a simple and elegant "stopping track" solution waiting to be found....
Otto

[PennsyPride]

Have the staging track gapped and normally dead. The operator would press a normally open switch to power the section to pull the consist in. He releases the button and the section is dead again. To pull the consist back out, press  the switch to power the dead section till the consist is backed out.

[Cajonpassfan]

Well, that's certainly simple, but it doesn't do what I'm asking for. There is over 30' of hidden trackage running left between the point the caboose disappears from view and the fouling point of the heading-out switches. That's about 4 minutes at restricted speed; the whole point is to have the stopping process automated so that the train crews don't have to wait around and do it manually.
Although I wouldn't mind a manual startup/departure procedure like the one suggested, as the engineer has to be there anyway to start his run out of staging and the trains enter visible running very quickly. It's the automated stopping with multiple locos that's the challenge here.
Thanks for the thoughts, Otto K.

[Cajonpassfan]

Thinking further, would something like a reed switch, placed between the rails, work? It would be normally closed, feeding power to the stopping section, and be activated by the passage of a magnet taped to the underside of a locomotive or car, interrupting the power. Better yet, are there reed switches sensitive enough to be activated by the passage of a motor (and its magnets)? At least on diesels, where the motors are quite close to the track.
Or, is there an electronic version of a reed switch?

Departure could be accomplished by means of a manually operated momentary switch, pushed just long enough for the magnet to leave its position above the reed switch?
I know this is old technology, but could it work? I like the idea because both the "sensor" and the "electric switch" are in the same package.
I need to get myself educated on reed switches. Thoughts?
Otto K.

[peteski]

Normally-closed reed switches are extremely rare and even if you found one, then the momentum of the train might make it coast past the reed switch anyway.  The other thing is that the leading locos on all the trains would have to have a magnet and be able to stop dead in their track over the reed switch.

Come to think of it I think the only way to get a normally closed reed switch is to find one with SPDT contacts. Also, most reed switches have fairly low current rating.

[John]

Here is how to do it ..

http://www.rr-cirkits.com/Clinics/GR-2012-Stopping.pdf

[jagged ben]

Here is how to do it ..

http://www.rr-cirkits.com/Clinics/GR-2012-Stopping.pdf

Um... is that simple? 

[jagged ben]

...  So I see the "stopping section" to be no more than 18 to 24".

The sensor to trigger the killswitch can be optical, electronic, or even mechanical; again simple is the key here. Good point about having to wait for the entire train to clear on departure...that would not be optimal. I want the visiting engineers to take their clearance card and go, and enjoy the experience rather than worrying about some obscure switch.

Well, maybe we'll get some other ideas.
Thanks guys!
Otto K.

I still think my idea is simple and workable.  The hardest part might just be matching sensor output to the relay coil.  If you go with an 18-24" stop section -- long enough for your longest possible loco consist --  then the problem of waiting for the entire train is no longer a problem.  Maybe I need to see your trackplan, but I'm thinking it would be something like: press the button to allow the train to proceed out of storage, wait for it to appear on the layout, then let go of the button and you're done.

[peteski]

Here is how to do it ..

http://www.rr-cirkits.com/Clinics/GR-2012-Stopping.pdf

I'm not very familiar with the JMRI scripting so I'm confused.  Is the JMRI part only there to control the signal aspect and the stopping block relay?   Is the actual braking and stopping done using the automatic braking on half-DCC signal in that block?  If yes, then the decoders have to be capable of doing that. Most European decoders can do that but I don't think the US-made decoders have that functionality.  Also the distance traveled when the automatic braking is engaged is most likely no absolute, so the locos could overshoot or stop short of the stopping point.

Or maybe I'm just not getting any of this?