Installing ABS Signals On Your Model Railroad (318)

In past videos I've introduced you to ABS signals, shown you how they work on the prototype and how to use them on a model railroad, and shown you how to build and wire the necessary circuit boards. So the final step is to show you how to install them on a model railroad. In this video I'll show you how those I installed on the Piedmont Southern work, and give you a look behind the fascia at how they are wired.
I checked and there are several sources for detection or restive wheelsets and a quick search will give you many options. Also I will be doing a video to show how I make mine so be patient.
Chapters
0:00 Intro
1:00 Review
4:00 How they work
7:15 Detector wheelset
10:37 Using detector wheelsets
11:50 Using light caboose or passenger car
13:25 Circuit board installation
17:18 Detector installation
20:24 Wrapup

[@BobSee-eg8pb]

Great video Larry. Appreciate your generosity in sharing your skill and knowledge in the hobby.

[@galethomas3995]

Good job Larry, very clear and helpful explanation.

[@peterjhillier7659]

Great Larry, thank you for all your hard Work and sharing, excellent. Keep safe.

[@jackmahle8680]

Thank you Larry for info keep it coming.😇👍

[@rl7881]

Another interesting video, thank you. However, something to be aware of is that by placing a 10k resistor across both axles of your bogie, you have an equivalent resistance of only 5k. This is because the resistors are connected in parallel. If you then had the same bogie at the opposite end of a wagon, your equivalent resistance is halved again, thus presenting only 2.5k for just one wagon. This reduces further if more than one modified wagon is included in a train. The caution is therefore to ensure you don’t exceed the minimum resistance which will initiate a short circuit on your controller, or indeed to draw additional current. Hope this is of help, and no offence intended.

[@elsdp-4560]

Thank you for sharing. 👍

[@robertlewis7237]

THANK YOU FOR VIDEO

[@randydobson1863]

hello larry its is randy and i like yours video is cool thanks friends randy

[@Robert-rx6rk]

I've now seen all three of your ABS signaling videos (287, 289, and 318). I think I can design and install a system based on block occupancy. But what about including turnout alignment into the logic? So far, there is enough info to set the aspect of an inter-block signal head, or to set the top head of a two-headed mast, or even to set the top and bottom heads of a two-headed mast. But, based on block occupancy alone and without knowing the position of the turnout, you could end up with a green-over-green; which could be useful, I suppose. How can we (mostly me) expand the PC board by adding an input and whatever other diodes or whatnot necessary to add red-over-green or green-over-red aspects based on both occupancy and turnout alignment? The alignment of the turnout could come from one of the eight tabs on the bottom of a Tortoise machine or from a wire soldered to the frog for those who have manual ground-throw turnouts. Not a complaint, at all. Just asking. Thanks.

[@TheDCCGuy]

In one of the original diagrams from the article that I showed in the video it does show how to use switch contacts on a Tortoise or other device to take the signal board logic to ground and display a red signal if the turnout is thrown. I will be using that feature on the Piedmont Southern, especially for crossovers, but likely will not do it for every turnout in a block. This really is not meant to be a complex ABS logic system and I believe that there are commercially available ones that can do a lot more. Because of copyright issues I cannot provide a copy of that diagram or the article. In the video I offered several suggestions as to how you can obtain a copy of the original articles.

[@Robert-rx6rk]

@@TheDCCGuy Thanks for responding. I will go back and re-watch the videos with a pad and pencil in hand. I'll also start looking for the original articles in the March and April 2001 MRRs.

[@michaelsmodelrailroading7665]

Thanks again for another illustrative video, which turns a seemingly complex subject into a number of not-so-complex steps. Functional signals do add an additional level of realism to a layout. They also add some visual drama for the casual spectator. The velcro attachment method is an ingenious idea that is very useful across a wide range of accessories. One question that comes to mind- how do you deal with power to sidings? Are they powered separately from the block to which they are attached, so that standing rolling stock on the sidings wont trigger an erroneous "occupied" signal?

[@TheDCCGuy]

I wire all sidings, spurs, and ancillary track directly to the main power bus and then use a sub-bus detection wire for the mainline detection rail. I plan to do a video on wiring for detection that will go over that.

[@davidpage6470]

Hi Larry another excellent video...I've watched quite a lot from here in England, especially adding items to the Piedmont Southern. Would it be possible to show the full operation of your excellent layout? We always see it in the background but I have never seen it in full operation. You never know, you might convert me to American Railroading! best regards David.

[@TheDCCGuy]

The problem is there are 2 major gaps that need filling. First there is a 4’ long bridge that needs to be built and second I need to install another helix to go between the main deck and the upper deck. I had hoped to tackle the bridge project starting last January but ran into a construction snag and some other issues. The helix just needs to get done when I get time since I won’t be repeating that build in videos as it will essentially be a repeat of the first. I hope to have an operating session next year this time and having the track completed will open up a whole new world of video topics.

[@brycepankau7128]

Just curious, once you have all of your signals installed and such, do you plan on adding macro cameras to your locomotive cabs so you can run your trains from "in cab"?

[@tomthetank924]

Larry would this set up work with g scale if you weren't using dcc without block detectors? thinking of insulated rail and wheel sets like you did with atlas boards unless you have a better idea any suggestions appreciated Have rc engines with railpro.thanks tom

[@jefferykeeper9034]

The Atlas signals system can be done this way by just using 4 wires, It may seem a little costly but it almost pug and play.

[@TheDCCGuy]

As I said in the video there are various commercial signal systems available, but as you point out this one can do it cheaper than most if not all the commercial ones but is not available off the shelf. Personally I wanted something that I can build myself, works independent of computers, and is not dependent on stock availability from a factory in China.

[@steveashcraft718]

@@TheDCCGuy DITTO!

[@HartfordWhaler]

How far into the block can a train go before the signal turns red? Asking because on my layout I may have to have the signal placed a bit in front of the activation sensor.

[@TheDCCGuy]

As soon as the loco wheels cross the block gap the signal will change. So it may be reasonable to place the signals accordingly.

[@HartfordWhaler]

@@TheDCCGuy thanks

[@davebaxter3370]

Is it possible to interface this signalling system into JMRI Panel Pro? If so a video on this would be appreciated.

[@TheDCCGuy]

No, this is a totally independent system. However an electronics guru might be able to figure out a way.

[@dundasjunctionmodelr.r-jam8267]

Ok Larry I am going to watch episode 269 and 287,289, what about Atlas system did you do a video using this system

[@TheDCCGuy]

Did not use Atlas.

[@4hillines67]

I'm still in the early stage of understanding signals, so this may be off. Larry, you mentioned your signal is default to green. From what I understand of RRs is that default is typically red, so if there is a fault, the block shuts down. Could you comment? Thanks!

[@TheDCCGuy]

I meant default in terms that the signal is on and green if the block ahead is clear thus allowing the train to enter that block without stopping. This is opposed to approach lighting where the signals are unlit until a train is detected approaching the signal. However if there was an equipment failure then I could see a rationale for a red to display assuming there was power to do it. Even where signals were powered with line power they typically had backup batteries as well. As I understand with semaphore signals some railroads preferred upper quadrants since if the arm swung down in a failure it would come to rest in the red stop position instead of the green position as would be the case with a lower quadrant semaphore.

[@ModelSceneryTutorials]

How is this wired for a single track that has two way traffic?

[@TheDCCGuy]

In the first video on ABS signals I showed a diagram from the Scherb article that shows how to wire a single track for bidirectional signals.

[@robertpetit57]

Larry, have you given any thought to selling the are PC boards for this project?

[@TheDCCGuy]

I have no desire to ever get into that rabbit hole. If you sell something then folks expect even more technical support than they expect now even though I have made the file available for free.

[@cllines604]

in one of your videos you said where to get the green and red signals for turn outs I can't find it help please. thanks

[@TheDCCGuy]

Do you mean the tall 3 aspect ones or the dwarf signals?

[@cllines604]

@@TheDCCGuy the tall one

[@TheDCCGuy]

Ok, those I got off eBay from a Chinese source. Try www.ebay.com/itm/352362316721

[@cllines604]

@@TheDCCGuy yes the tall one

[@dundasjunctionmodelr.r-jam8267]

Larry what make signal heads are you using

[@TheDCCGuy]

www.ebay.com/itm/352362316721

[@dundasjunctionmodelr.r-jam8267]

Thanks Larry but they don’t ship to Canada

[@TheDCCGuy]

Search ebay for other vendors of the same products. There may be some in the US who import them here and would sell to you.

[@ronaldrondeau7870]

great info but for my switching layout not very usefull

[@michaelsmodelrailroading7665]

Functioning dwarf signals protecting your turnouts might be a more appropriate option for a small switching layout. And if your layout includes a segment of supposed through "main line," protective ABS signals at either end of that block might also provide some operating interest.