I use MSS, which is an ABS signal system. There are no resistors on wheelsets. There is no computer. There is very little electronics to understand--just follow the directions.
I am hoping to build an interlocking, someday. I plan for it to be a double cross-over.
Ed
7j43k I use MSS, which is an ABS signal system. There are no resistors on wheelsets. There is no computer. There is very little electronics to understand--just follow the directions. I am hoping to build an interlocking, someday. I plan for it to be a double cross-over. Ed
Ed,
I have looked at that site/product several times and I wish I could say I understand it?
If I am understanding it correctly, it requires multiple detectors for each signaled block? Seems that would be expensive?
Please fill me in.
My system uses no solid state logic, and lacks what appears to be lots of "layers"?
And again, what I am doing appears to be just the opposite, I am only modeling the interlocking or "absolute" signals.
I use inductive detectors, but not resistor wheel sets. I simply run every train with a lighted/resistance tail car - but I do model the "caboose" era.
Again, please explain a little, I would like to understand what they are doing. Their web photos look more wiring intense than my hard wired relay logic?
Sheldon
Well, the Maryland and Pennsylvania RR was dark. So I don't use signals. Some where along the way I'll have road crossing signals, but that's it.
I think it's a neat thing to do, although as I read here, everyone has to do a modified version. Way down on my list of things is to represent the B&O bridge over the Baltimore terminal of the Ma&Pa. If I do, I'll put a couple of signals on it. They won't be real, but I'll rig up a system for them to automatically change.
Paul
ATLANTIC CENTRALEd, I have looked at that site/product several times and I wish I could say I understand it? If I am understanding it correctly, it requires multiple detectors for each signaled block? Seems that would be expensive?
MSS is designed to work with only a loco drawing current.
It uses a current detector for each block to immediately recognize when a loco enters a new block and optical detectors at the block boundaries to recognize when a train is straddling two blocks.
when a loco leaves a block, the previously occupied block is not recognized as clear until the optical dectector at the boundary is no longer active.
another way of looking at it is that a block is recognized as as occupied when either current is drawn within the block or an optical detector is active at the boundary. This means a train w/o a car drawing current can be backed into a block and the block will be recognized as occupied.
of course there is no way to recognize when part of a train w/o a car drawing current is left in a block w/o a loco.
greg - Philadelphia & Reading / Reading
Another case of TANSTAAFL - there ain't no such thing as a free lunch. No resistor wheelsetson cars, but you need THREE detection devices per block including one that is the single type you'd need for the resistor wheels anyway. I can see the utility for N scale where plastic wheels still seem to rule the day, it incredibly easy to add resistors to metal wheelsets in HO and larger.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
rrinker Another case of TANSTAAFL - there ain't no such thing as a free lunch. No resistor wheelsetson cars, but you need THREE detection devices per block including one that is the single type you'd need for the resistor wheels anyway. --Randy
Another case of TANSTAAFL - there ain't no such thing as a free lunch. No resistor wheelsetson cars, but you need THREE detection devices per block including one that is the single type you'd need for the resistor wheels anyway.
Actually, Randy, you only need TWO detection devices per block.
ATLANTIC CENTRAL Ed, I have looked at that site/product several times and I wish I could say I understand it? If I am understanding it correctly, it requires multiple detectors for each signaled block? Seems that would be expensive? Please fill me in. My system uses no solid state logic, and lacks what appears to be lots of "layers"? And again, what I am doing appears to be just the opposite, I am only modeling the interlocking or "absolute" signals. I use inductive detectors, but not resistor wheel sets. I simply run every train with a lighted/resistance tail car - but I do model the "caboose" era. Again, please explain a little, I would like to understand what they are doing. Their web photos look more wiring intense than my hard wired relay logic? Sheldon
Sheldon,
It requires one current detector per block, and one optical detector per block. Not particularly expensive, in my opinion.
Besides the detection system, there is also the logic layer, which is "entirely" based on how various wires in RJ45 cables are connected at junction points.
Yes, MSS is basically an ABS signal system. As such, it only does block occupancy, and not such things as routing indication*. BUT. I believe it CAN accept such things, including CTC. As I said, I'm planning on building an interlocking, and it will be plopped right down in the middle of double-tracked bi-directional ABS signaling. And it will be integrated with it. Because it will be a model of a UP crossover in the middle of Nowhere, Wyoming, there will be no tower. Control will be "remote".
I think this is the best presentation of how things work:
http://www.modularsignalsystem.info/MSSUserGuide1.pdf
http://www.modularsignalsystem.info/MSSUserGuide2.pdf
*That's not entirely true. With MSS, if a switch is set against you, you will get a red. THAT is not block occupancy.
gregc ATLANTIC CENTRAL Ed, I have looked at that site/product several times and I wish I could say I understand it? If I am understanding it correctly, it requires multiple detectors for each signaled block? Seems that would be expensive? MSS is designed to work with only a loco drawing current. It uses a current detector for each block to immediately recognize when a loco enters a new block and optical detectors at the block boundaries to recognize when a train is straddling two blocks. when a loco leaves a block, the previously occupied block is not recognized as clear until the optical dectector at the boundary is no longer active. another way of looking at it is that a block is recognized as as occupied when either current is drawn within the block or an optical detector is active at the boundary. This means a train w/o a car drawing current can be backed into a block and the block will be recognized as occupied. of course there is no way to recognize when part of a train w/o a car drawing current is left in a block w/o a loco.
ATLANTIC CENTRAL Ed, I have looked at that site/product several times and I wish I could say I understand it? If I am understanding it correctly, it requires multiple detectors for each signaled block? Seems that would be expensive?
Greg, thanks for that explaination, it makes perfect sense explained that way, on their web site not so much.
And their drawings do show more than two current detection sections per signal block?
That's a lot of work/expense to go thru just to avoid resistor wheels or tail end resistor/lighted cars.
And all it does is provide the detection logic? Then you still need your signal logic?
OK, I get it.
What I do is much simpler, at least to me. But all my signal logic is hard wired thru relays, not "programable". I do not have seperate layers for detection and signal logic. I use inductive detectors. Those boards have dry contact relays which drive the signal circuits directly. The signal logic goes thru relay contacts that mirror the position of every turnout. I have about 300 ice cube relays.......but they only cost me about a $1 each - wire is cheap.
But again, all my signals are interlocking signals.
Thanks,
gregc of course there is no way to recognize when part of a train w/o a car drawing current is left in a block w/o a loco.
Yes, that is unfortunate.
I see two ways that can happen:
1. A train parts because of bad trackwork and/or poor coupler installation. I would recommend fixing that, and it won't happen again.
2. Part of a train is left on the main, while a loco switches a siding. It should be noted that as long as the track switch is thrown for the siding, signals will go to red. If the switch is thrown to the main, and the loco is on the main, the loco will be detected. There COULD be a problem if part of the train is left on the main AND the loco ducks into the siding AND the switch is thrown to the main. How often is that going to happen?
I do not think this problem (#2, above) has been addressed in MSS. Yet. I seems to me one could put a couple of "extra" optical detectors on the main where a cut of cars might be left.
By the way, you CAN put resistors on wheelsets and use MSS. If you choose.
ATLANTIC CENTRAL And their drawings do show more than two current detection sections per signal block?
The reason you see more than one current detector per block on those drawings is because MSS is designed for Free-mo*. If you are not doing Free-mo, you only need ONE current detector per block.
*With Free-mo, you might have 5 modules built by 5 guys in one block. You would only need one current detector, but which guy is the guy who's gonna be responsible for it. Thus, EVERYONE has to have a current detector.
Free-mo is designed so that the modules can be assembled in almost any possible way. To maintain this flexibility, MSS equipped Free-mo modules all have to have current detectors. For a "regular" layout, you'd only need one.
ATLANTIC CENTRAL . . . resistor wheels or tail end resistor/lighted cars.
. . . resistor wheels or tail end resistor/lighted cars.
This is my plan. The layout is still under construction with tons of stuff to do other than fiddling with the signals. I have set up, wired, and tested the signal and detection ststems using locos and lighted passenger cars (including club cars with lighted drumheads on the rear end). Everything functions as expected. I plan to add FREDs to the freight trains that do not have resistor wheelsets or current-drawing features. Seems easy enough; plus the added panache of working FREDs.
Robert
LINK to SNSR Blog
Ed, armed with the new understanding that it is a multi layer system and that the first layer is just detection, I looked at the web site again and I get it now.
But here is the thing, first it is geared toward modern ABS systems used on the prototype today.
Yes, I'm sure CTC or tower interlockings can be intergrated into it, as the signal logic is a different "layer".
But who has a model railroad that needs "advance approach" (flashing yellow) indications? Who has that much space? That long of a main line? Especially between interlocking points? I'm getting ready to rebuild 8-10 scale miles of double track in 1700 sq feet - I don't have room for advance approach ABS......
I don't even use every possible "approach" (yellow) indication on my system, (I fake half of them).
I model the 1950's, "advance approach" was often done with seperate "approach" signals, not by flashing the second block out.
I run long trains, in relatively tight intervals, my blocks are long, like the trains, all that would never work. Some selective compression is needed.
But again, it has a lot to do with the era and locale you are modeling. I'm modeling the east, in the 50's, double track, bi directional, CTC.
And my control system is DC.........
7j43k ATLANTIC CENTRAL And their drawings do show more than two current detection sections per signal block? Sheldon, The reason you see more than one current detector per block on those drawings is because MSS is designed for Free-mo*. If you are not doing Free-mo, you only need ONE current detector per block. Ed *With Free-mo, you might have 5 modules built by 5 guys in one block. You would only need one current detector, but which guy is the guy who's gonna be responsible for it. Thus, EVERYONE has to have a current detector. Free-mo is designed so that the modules can be assembled in almost any possible way. To maintain this flexibility, MSS equipped Free-mo modules all have to have current detectors. For a "regular" layout, you'd only need one.
OK, I get that now also.
Please forgive me, I'm not into the portable module thing at all......
My mind never goes to the needs of those guys.....
I think Advance Approach is neat, 'cause I like flashing lights. Aesthetics, you know. Actually, you don't have to use it. My signals aren't set up for it. There're just plain old red, yellow, and green.
You model the East, huh? And they didn't have ABS signaling? Wow, who knew?
Double track? Bi-directional? CTC? Sounds perfect for an ABS base.
Oh, yeah. You're running DC? Seems to me MSS would still work. With a little help.
dehusman Another system, that is probably the least modeled, is "rule 251" territory or "double track". It has two main tracks and operated with current of traffic (all the trains go one way on one track and the other way on the other track. It has ABS in the current of traffic and NO signals for running against the current of traffic. It was one of the most common signal systems from WW1 to the 1970's or 80's, especially on routes with a lot of passenger trains. It can handle a HUGE volume of trains (as long as nothing goes wrong or stops on one of the tracks). In the 60's, 70's and 80's the railroads converted most of the double track (each track signalled in one direction) to two main tracks (both tracks signalled in both directions) in order to increase capacity and flexibility.
Another system, that is probably the least modeled, is "rule 251" territory or "double track". It has two main tracks and operated with current of traffic (all the trains go one way on one track and the other way on the other track. It has ABS in the current of traffic and NO signals for running against the current of traffic. It was one of the most common signal systems from WW1 to the 1970's or 80's, especially on routes with a lot of passenger trains. It can handle a HUGE volume of trains (as long as nothing goes wrong or stops on one of the tracks). In the 60's, 70's and 80's the railroads converted most of the double track (each track signalled in one direction) to two main tracks (both tracks signalled in both directions) in order to increase capacity and flexibility.
I like signals, but on my layout they are imaginary. The wayside signals are dummy, but located following my prototype's practice. The signal system imagined is ABS with a couple of manual interlockings. (I DO like the time table and train order system of operation.)
I also have two main track, signalled (still imaginary) for current of traffic operation. Uniform Code of Operating Rules 1968 edition Rule 450-453, not Rule 251 as appears in most rule books. The point where two tracks becomes one gives me a chance to issue the Form V Check of Trains train order.
Jeff
7j43k Sheldon, I think Advance Approach is neat, 'cause I like flashing lights. Aesthetics, you know. Actually, you don't have to use it. My signals aren't set up for it. There're just plain old red, yellow, and green. You model the East, huh? And they didn't have ABS signaling? Wow, who knew? Double track? Bi-directional? CTC? Sounds perfect for an ABS base. Ed Oh, yeah. You're running DC? Seems to me MSS would still work. With a little help.
Ed, you misunderstand a little. Eastern roads use/used ABS, BUT, back in the day, signal systems were less standardized then they are in modern railroading.
B&O, PRR, C&O, N&W, etc, all had their own special systems with different aspects and rules.
CTC uses/can use, ABS signals between interlockings - assumming there is enough distance between interlocking points to have additional blocks - we are taking about the crowed east....
But on a model layout, if you make a block twice the length of a train, pretty short by prototype standards, how many blocks are you going to have before the next interlocking, siding, junction or other control point that would require an absolute signal on the prototype?
Again, there is a big difference between CTC and non CTC trackage with only ABS.
Or like like the PRR who used "tower control" on most of the system.
And again, there is a big difference between what was done in 1953, and how it is done today.
Ed, MSS is way more complex than what I do, way more than I need. It would not benefit me at all.
In most cases I only have one mainline block between each interlocking.
My interlockings really work, meaning that once the route is set, and the train enters interlocking territory, turnouts cannot be accidently thrown under the train.
And I have ATC (automatic train control), if an engineer runs a red signal, his train shuts down and stops......
and I have wireless radio throttles, all with DC.........
I suppose there's more than one way to skin a cat.
Though 98% of cats polled thought that was WAY too many ways! The other 2% were busy chewing on rodents.
jeffhergertI like signals, but on my layout they are imaginary. The wayside signals are dummy, but located following my prototype's practice. The signal system imagined is ABS with a couple of manual interlockings.
I like to suggest to people using TWC that they pretend they have ABS. It makes no difference in the track warrants they issue, other then to allow following moves in the same limits, very handy on a model railroad.
Dave H. Painted side goes up. My website : wnbranch.com