Just getting into stuff that will require me to establish blocks and I am not sure how to determine block sizes and where boundaries should be. When I initially built my N scale layout, I included a lot of rail gaps in the hope that it would give me flexibility when I got around to creating the actual blocks. Also did that so I could break everything up into multiple power districts. Now I am at the point where I need to mash all this together to form blocks on my JMRI panels. The driver for creation of these blocks is for block occupancy detection and to support signals. I not only need the block occupancy info for signal logic but I need block boundaries to identify signal mast placement. Some blocks are straight forward since my layout has every turnout electrically gapped from any connecting track. As a result, I can easily make every turnout a separate block so I am not really worried about them. I also have some long sections of track with no turnouts so it seems logical to me to make them a single block. I also have a string of turnouts end to end at a yard throat and it seems logical to make that string of turnouts into a single block as well as each individual yard track as a block. I also have multiple sidings and industry spurs that seem right for individual blocks. However, this still leaves me with a lot of track that has a number of turnouts close together where there is insufficient spacing between the turnouts to call them individual blocks and I am not sure how to handle those sections which have a lot of little sections close together. My current thinking is that I should go ahead and treat each little section of track between turnouts as a named block so I will have all the pieces named and identified. Then, for signal logic, I should plan to group some of these small (electrical) blocks into a larger (logical) block so that I can place a signal mast according to logical blocks and use the logical blocks for determining signal lights. Does this sound right? Other approaches? Paul D
I would say that it has to do with where trackwork branches such as passing siding. sidings are your basic building blocks. Other spurs leading onto mains would have signs indicating enter/leaving CTC. I'm no expert, but you wiould likely need some kind of radio and signal permission to enter the CTC area. I live near a pretty heavy mainline. There are specific places with extra sidings where I actually see trains get stopped. I would say that your block length should be one unit, or train length. On a model railroad it just depends on how much space you have as most won't be running 100+ car length trains. Also, try pricing out signals and then see how much you want to add in that is extra. Signals and hardware are expensive.
A fantastic resource for this question is Andy Sperandeo's Easy Model Railroad Wiring. He shows exactly how to set up blocks and all of the many pre-DCC methods of controlling multiple cabs. Very complex ideas are shown but he clearly describes the process. The book is available used on websites. I'm looking at an elaborate walk-around system for two main cabs and then local priority control for some small areas such as yards. This will allow three or people to run on different areas at the same time and the priority system keeps them from running into each other
I have done this on my ATSF layout based on function. Main lines are on a separate power district than everything else. I set the length based on what I anticipate the traffic to be. Since I am running a double track main, those power districts are broken into 12 equal sections. For the complexity of the Barstow yard, I have 16 power districts and so on. In each case it is either sized by length or sized based on traffic congestion. As an example for the Barstow yard, the passenger station terminal tracks are their own power district mostly because all the passenger locomotive equipment either have sound or eventually all will have sound. Because the yard was very busy with lots of switching activity several ladder tracks make up a power district. The northern and southern drill tracks are separate power districts by themselves. And so on down to the end of industry tracks, in many cases there is only one power district for the double track main section running in the open desert..... That worked well for me, I never had any shorts affecting anything else when there was a derailment anywhere else on the layout.
Well, the nice thing about yards is they don’t have signals. Once you know you want signals, you then have to know, where is your railroad? Western signals make sense, Eastern signals are so complicated even veteran engineers argue about meanings. You have to LOVE logic to want signals, it’s required. If you have ever said “it’s good enough”, signals are just flashy lights. Why? In real life, people die if the signals aren’t wired correctly. Is it fun? I enjoyed using relays to create a signal system for my two NTrak corners, and watch them actually work.
Paul D, you pretty much describe the track on my railroad. My layout is a two track main, twice around loop with 7 control points. I logically grouped turnouts into a control point, such as a crossover, as a separate "block" from the track between the control points. One particular CP is complex and divided into three physical blocks that can support three simultaneous routes. I'm still working on the signal logic for that one. In the yard I grouped the switches forming the ladder into a single block separate from the yard tracks.
I second the thumbs up to Sperandeo's book. It is chock full of real info on blocks and pre DCC methods. This may not be prototypical but offers a great deal of action for users. I am planning on using my own signalling system to show which cabs are controlling each block. Again not prototypical, but a three LED bulb head will be at each end of the block boundaries and light up a color for each cab. I prefer this idea to a lit layout plan so the operators look at the layout, not the controls. I found LED bulbs with no wires very cheaply, with resistor kits to adjust each color. Purists may disagree but my layout will be designed for multiple operators in a pre-electronics paradigm.
Paul, I'm just curious, which railroad/era/locale are you modeling? Turnout indicators are signals, but technically even signs along the ROW are signals, too. They're all just not what we usually think of as signals.
