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DCS and Legacy enable operating multiple trains on the same section of track, and when I have three trains running on the single track mainline of my railroad, it gets exciting and too often there are cornfield meets. Yesterday the Reading's Crusader slammed into the caboose of a Long Island RR freight and sent the caboose down 40 inches to the concrete floor.

 

The RMT caboose landed on its wheels, so there was no apparent damage which is a testament to its ruggedness, but RMT man figure was thrown overboard and at the last report from the hospital, he is in a full body cast.

 

Here is where I am going with this post. I think it is time for the advent of proximity sensors in locomotives as an extra cost option. The technology exists in the automobile industry. Is it possible that an accident avoidance feature can be programmed into a TIU or whatever makes Legacy tick?

 

The architecture for a sensor system might go something like this:

> Manual activation of the system;

> Sensor ON full time while the system is activated;

> Sensor is built into the DCS TIU or the Legacy processor. If not feasible, incorporate the sensor into the locomotive;

> RF detection signal frequency and strength suitable for short range;

> Command signal from the sensor by copper path to the locomotive's electronics. Command signal reduces the operating voltage to the motor of its locomotive when the range to the train ahead is 6 to 12" inches;

> Signal to adjust the operating motor voltage of the approaching locomotive continues while the range to the train ahead is within 6 to 12 inches.

 

What are your thoughts?

 

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Guys,

 

I realize that my opinion may not be popular on this subject, but since you asked for it......Here goes nothin'!

 

With what the previous poster said crashes were fun in olden days! Plus what these program changes would cost (which is a lot I would presume), I would go with the cheapest option which would be to do nothing and hope a similar accident does not occur in the future.

 

It shouldn't if one is more observant.

 

Guys, I don't want to rain on anybody's parade but since no damage occurred the cost benefit scenario was minimal.

 

However, if we were talking locomotive big boy here, I suppose I would stop the train well before the collision.

 

Mike Maurice

Originally Posted by NJCJOE:
Originally Posted by gunrunnerjohn:

One issue I see with such a sensor is curves and scenery.  As you round a curve, the sensor would be seeing the stuff along the side of the track coming on like an imminent collision.

You could always put the sensor between the rails of the track.

I think for it to see the train ahead and react in time to avoid the collision, it would still have issues with scenery.  This is not as simple a task as it might seem.

 

I think Nicole is on to the solution, pay attention to what you're doing.   However, I have to say I've come up on a couple of slow freights in the club layout, sometimes you don't have visibility without moving around, and occasionally I get lazy.

Originally Posted by bigdodgetrain:
Originally Posted by Rusty Traque:

Hmmm.

 

When I was a kid, crashes were half the fun!

 

Rusty

true, however trains cost a little more now.

I understand that, particularly speaking as one who once inadvertantly sent an S scale GP9 I was detailing airborne because I wasn't paying attention. (Hint: GP9's can't fly, but do a wonderful simulation of a brick falling and becoming an instant kit...)

 

I already had a pretty fair amount of "sweat equity" put into it, too.  It was just about ready for painting.

 

As the philosopher once said: "Stuff happens."

 

Rusty

I avoid the whole situation by running only one train per loop, but  . . . looking at this, I immediately distinguish two situations:

 

Commercial products: I could see a company like Lionel or MTH engineering, designing and producing a system that would work like active cruise on some cars now.  A small sensor would detect the train ahead and slow the cruise/shut down power.  I think it could be designed to look a bit around curves and to ignore nearby buildings and tunnel entrances (I hope).  I imagine it would cost $150 or so to add to locos and would probably avoid only 90% of possible collisions.

 

Homemade projects: it is barely possible a good hobbyist could design something like this themselves.  Were I to try, I would expect to take a while with trial and error but would take this approach: small transmitter-receivers (IR or RF) of very limited range, on both the front of each loco and the back of each train (caboose or last passenger car, etc.).  When any of them receive a signal (a caboose sensors senses a loco coming up behind) they broadcast to a receiver connected to the a programmable unit at the transformer: any combination of two receiving at the same times and the programmable controller cuts the power.  This would be a really fun project to watch someone else do.  I don't plan to undertake it, but it is interesting.

It's not that difficult to do, but you need a lot of relays and careful placement of sensors so a train doesn't accidentally stop itself. You need "stop sections" on either side of blocks and logic that only cuts the power to the "stop section" if the blocks on both sides of it are occupied. You can use insulated rail (3-rail only) or you can use a combination of optical and current-sensing to protect a block (2-rail and 3-rail.)

 

The relays would basically be SPDT with the normally closed tied to your high (18v) source and with the low (6v) source and the hot rail on the relay common (you could also tie your red signal on the normally open connection.) This is a "make-before-break" that keeps a voltage on the track so as not to cycle the E-unit but low enough to stall the locomotive. Cruise control may try to keep the engine running, so look for a higher current draw on the 6v source.

Lee's approach sounds interesting.  I'd suspect that the IR would be the way to go, too many variables with RF.  If the locomotive was receiving the signal and the transmitter was on the rear of the consist, you could assume that anytime you receive a signal, that you are probably close to the rear of another train.  Of course, dealing with adjacent tracks would have to be accounted for, but you could also have the IR beam modulated and track specific.

Thanks for the info Barry. I had an thought that someone would put crash avoidance into trains.

 

As for you Loop Runners, the day will come when you show off more than one train per loop and .......... badda bing!

 

My train driving skills are pretty good unless I have a 2-year old grandson under one arm, and a 5-year old granddaughter running trains too. I also have not yet developed Superman's X-ray vision to see through buildings, but I am working on it. The crash was in dark territory behind an apartment building and the El.

 

I admit to being imperfect. Therefore I find myself in occasional need of technological help and sometimes assistance from a Higher Authority.

 

If you haven't heard of Stan Roy, look him up.  His layout is featured in several books and videos.  Tom McComas' "Great Toy Train Layouts of America Parts 1-6" DVD is one.

 

Stan runs 32 trains simultaneously, all start and stop automatically as needed:  if coming up behind another train, and at intersections and switches to let other trains pass, no collisions.  The action is regulated by magnets mounted in the locomotives that trigger trackside relays.  It's all 80's technology relay logic.   It's pretty amazing to watch.

 

I've actually thought of a way to do a pseudo GPS for a model RR that could work with command control. Because GPS doesn't work well indoors, instead use RF antennas at different points along the line. Each antenna creates a RF signal "bubble." A computer will track train position by RF signal strength and which bubble(s) the train occupies.

Let me see if I understand the question: using DCS or Legacy you want to be able to start-and-stop trains to avoid rear-end collisions like Lionel showed us how to do nearly 60 years ago in the 1954 Operating Instruction Manual using conventional post-war locomotives with insulated outside rails and relays?  How ironic!  Isn’t this new technology great? 

 

I’ve been using relays since the early 1970’s to control multiple trains on the same track and I was quite disappointed after I bought my first TMCC engine and added TMCC to my layout in the late 1990’s to find out that I couldn’t do that with TMCC locomotives as they will not automatically restart running in forward when the relay de-energizes and the power to the block returns. 

 

But I’ll admit that I like the bells & whistles so much that I’ve bought a few more TMCC locos as well as some MTH with PS and PS-2.  At least with the MTH locos I can lock them in forward but then I lose the sounds.

 

Bill

Crash protection is a neat idea, maybe even a warning beep before impact .  Im very thankful for the little red button.  The  fun ramps up with all of my trains running at the same time.  I have a chair by the controls but I never sit in it.  I love DCS.

 

It's easier for me to run trains solo with no crashes late at night (and zero volume... you know).  I think My processor slows down with sights, sounds and smoke in all directions, crash rate also increases with kids or guests.  I think 1/2 my incidents are because i forgot a switch position.  


Since we dont run them at blistering speeds the trains and equipment have always been fine.  I do however partially credit that to the Z4K and Z750 protection. 

Originally Posted by WftTrains:

 

 

I’ve been using relays since the early 1970’s to control multiple trains on the same track and I was quite disappointed after I bought my first TMCC engine and added TMCC to my layout in the late 1990’s to find out that I couldn’t do that with TMCC locomotives as they will not automatically restart running in forward when the relay de-energizes and the power to the block returns. 

 


Bill

I have the same problem with a few locos. I wrote Lionel about possibility altering the board wiring so it could start in forward,but just got a snitty answer. "We do not support 3rd party alteration of our products".

 

Dale H

Originally Posted by Flash:
I've actually thought of a way to do a pseudo GPS for a model RR that could work with command control. Because GPS doesn't work well indoors, instead use RF antennas at different points along the line. Each antenna creates a RF signal "bubble." A computer will track train position by RF signal strength and which bubble(s) the train occupies.

Given the resolution of the best GPS receivers is 15-20 feet under ideal conditions, exactly how big a layout do I need to use this?

 

Using RF has a similar issue, designing a system that would be consistent in a wide variety of layouts (or even one) is a daunting task.  There are a ton of things that would affect the RF signal strength, not to mention the design of the locomotives and antennas would also be a major factor. Finally, with adjacent tracks, it would be difficult to impossible to determine which track the train was on even if you solved the other issues.

 

Originally Posted by Dale H:
Originally Posted by WftTrains:

 

 

I’ve been using relays since the early 1970’s to control multiple trains on the same track and I was quite disappointed after I bought my first TMCC engine and added TMCC to my layout in the late 1990’s to find out that I couldn’t do that with TMCC locomotives as they will not automatically restart running in forward when the relay de-energizes and the power to the block returns. 

 


Bill

I have the same problem with a few locos. I wrote Lionel about possibility altering the board wiring so it could start in forward,but just got a snitty answer. "We do not support 3rd party alteration of our products".

 

Dale H

 

Hi Dale:

 

Thanks for your feedback.

 

I had considered adding a resistor into the NO. circuit when the relay is energized to drop the voltage to the track block instead of shutting the block off altogether.  This is a variation of the Lionel “preserving reversing without locking out the e-unit” procedure which would allow the TMCC loco (or any other loco) to come to a stop without shutting off.  But when I asked a question about the feasibility of doing this on another forum 10 or so years ago I was told that doing that could damage the TMCC electronics.  What do you think?

 

Bill

Originally Posted by WftTrains:
Originally Posted by Dale H:
Originally Posted by WftTrains:

 

 

I’ve been using relays since the early 1970’s to control multiple trains on the same track and I was quite disappointed after I bought my first TMCC engine and added TMCC to my layout in the late 1990’s to find out that I couldn’t do that with TMCC locomotives as they will not automatically restart running in forward when the relay de-energizes and the power to the block returns. 

 


Bill

I have the same problem with a few locos. I wrote Lionel about possibility altering the board wiring so it could start in forward,but just got a snitty answer. "We do not support 3rd party alteration of our products".

 

Dale H

 

Hi Dale:

 

Thanks for your feedback.

 

I had considered adding a resistor into the NO circuit when the relay is energized to drop the voltage to the track block instead of shutting the block off altogether.  This is a variation of the Lionel “preserving reversing without locking out the e-unit” procedure which would allow the TMCC loco (or any other loco) to come to a stop without shutting off.  But when I asked a question about the feasibility of doing this on another forum 10 or so years ago I was told that doing that could damage the TMCC electronics.  What do you think?

 

Bill

 

Originally Posted by N.Q.D.Y.:

My personal feeling is that driver training needs to be more thorough if accidents are frequent.  Technology is not always the answer.

Copy that Nicole.  I've run two trains on one line is the opposite direction using conventional control.  My GG1 ran overhead and the steamer ran 3 rail using my old PW ZW.  That's called hands on operation.

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