#LyX 2.2 created this file. For more info see http://www.lyx.org/ \lyxformat 508 \begin_document \begin_header \save_transient_properties true \origin unavailable \textclass paper \use_default_options true \maintain_unincluded_children false \language english \language_package default \inputencoding auto \fontencoding global \font_roman "default" "default" \font_sans "default" "default" \font_typewriter "default" "default" \font_math "auto" "auto" \font_default_family default \use_non_tex_fonts false \font_sc false \font_osf false \font_sf_scale 100 100 \font_tt_scale 100 100 \graphics default \default_output_format default \output_sync 0 \bibtex_command default \index_command default \paperfontsize default \spacing single \use_hyperref false \papersize default \use_geometry true \use_package amsmath 1 \use_package amssymb 1 \use_package cancel 1 \use_package esint 1 \use_package mathdots 1 \use_package mathtools 1 \use_package mhchem 1 \use_package stackrel 1 \use_package stmaryrd 1 \use_package undertilde 1 \cite_engine basic \cite_engine_type default \biblio_style plain \use_bibtopic false \use_indices false \paperorientation portrait \suppress_date false \justification true \use_refstyle 1 \index Index \shortcut idx \color #008000 \end_index \leftmargin 1cm \topmargin 1cm \rightmargin 1cm \bottommargin 1cm \secnumdepth 3 \tocdepth 3 \paragraph_separation indent \paragraph_indentation 0bp \quotes_language english \papercolumns 1 \papersides 1 \paperpagestyle default \tracking_changes false \output_changes false \html_math_output 0 \html_css_as_file 0 \html_be_strict false \end_header \begin_body \begin_layout Title Minetest Mod - Advanced Trains [advtrains] \end_layout \begin_layout Title Interlocking System Guide \end_layout \begin_layout Section Introduction \end_layout \begin_layout Standard In real-world railways, a so-called interlocking system is a set of railway signals and trackside equipment. Its purpose is to prevent conflicting train movements which otherwise could result in derailing or colliding trains. If you want more information, just search for \begin_inset Quotes eld \end_inset railway interlocking \begin_inset Quotes erd \end_inset on the internet. \end_layout \begin_layout Standard Real-world interlocking systems perform this task by setting routes. A route is a path along a track that a train can safely pass. To set a route for a train, the signalman (the operator of a signal box) has to set switches (turnouts) to the correct position and lock them in order to make a signal for a train show \begin_inset Quotes eld \end_inset Proceed \begin_inset Quotes erd \end_inset . In newer systems, this is done automatically by the interlocking system. A route can not be set if switches are locked to a wrong position by another route or if any portion of the route is occupied by a train. \end_layout \begin_layout Standard The interlocking system in this Minetest mod tries to follow real-world interlocking systems as far as applicable. It divides tracks into track sections and implements a route setting mechanism following the same principle. \end_layout \begin_layout Standard However, for the sake of simplicity of implementation and usage, not all concepts of real-world interlocking have been taken over. Especially, there is no mechanism for overlap. \end_layout \begin_layout Standard If you are looking for a place to learn how real-world interlocking systems work, have a look at \begin_inset Quotes eld \end_inset SimSig \begin_inset Quotes erd \end_inset . By looking at their simulations, you can obtain experience on how to set up your own interlocking systems in AdvTrains. The SimSig glossary is a good place to look up unknown terms in this document. \end_layout \begin_layout Section Setting up track sections \end_layout \begin_layout Standard In the real world, a line of track is divided into so-called track sections, or track circuits. Those systems often can not tell where exactly a train is, but only which track sections it occupies. A route can never be set through an occupied track section. \end_layout \begin_layout Standard A track section often covers: \end_layout \begin_layout Itemize A section on a main running line, between two signals \end_layout \begin_layout Itemize A single turnout \end_layout \begin_layout Itemize A rail crossing, or a set of turnouts acting as a double/single slip switch \end_layout \begin_layout Itemize A siding \end_layout \begin_layout Standard You will find some examples on how to interlock certain patterns later. \end_layout \begin_layout Subsection Track Circuit Breaks \end_layout \begin_layout Standard In this mod, you will not directly configure the locations of track sections. Instead, you designate the borders of each track section using a special node, the Track Circuit Break, abbreviated TCB. \end_layout \begin_layout Standard For example, if you want to create a track section for a piece of a main running line, you set up two TCBs at the ends of this track circuit. \end_layout \begin_layout Standard Setting up a TCB works as follows: \end_layout \begin_layout Enumerate Place a TCB node somewhere near the place where the circuit break is going to be located. \end_layout \begin_layout Enumerate Right-click the TCB node \end_layout \begin_layout Enumerate Punch the rail which should act as TCB \end_layout \begin_layout Standard The result should look like this: \end_layout \begin_layout Standard \begin_inset Graphics filename lyx_img/screenshot_20180830_142551.png width 10cm \end_inset \end_layout \begin_layout Standard Now you have assigned the TCB node to a rail. Right-click the TCB node once again. This will bring up a form which looks as follows: \end_layout \begin_layout Standard \begin_inset Graphics filename lyx_img/Bildschirmfoto_2018-08-30_14-26-35.png width 10cm \end_inset \end_layout \begin_layout Standard You see that the form is divided in side A and side B. To designate where each side is, a marker is displayed on the rail. You can always make this marker show up by punching the TCB node, and remove it by punching the marker. Both sides are shown as \begin_inset Quotes eld \end_inset End of interlocking \begin_inset Quotes erd \end_inset . This means that there is no track section set up at this place. \end_layout \begin_layout Standard You should repeat this procedure once again a few meters away from the first TCB to create a second TCB on the same track. \end_layout \begin_layout Standard \begin_inset Graphics filename lyx_img/Bildschirmfoto_2018-08-30_14-32-48.png width 10cm \end_inset \end_layout \begin_layout Standard Once you have both bordering TCBs set up, you can now create the actual track section. To do this: \end_layout \begin_layout Enumerate Right-click one of the TCBs \end_layout \begin_layout Enumerate Locate the correct side (A or B) to create the track section \end_layout \begin_layout Enumerate Click \begin_inset Quotes eld \end_inset Create interlocked Track Section \begin_inset Quotes erd \end_inset in the formspec on the chosen side. \end_layout \begin_layout Standard Now, the text on the formspec has changed. It shows something like this: \end_layout \begin_layout Standard \begin_inset Graphics filename lyx_img/Bildschirmfoto_2018-08-30_14-27-25.png width 5cm \end_inset \end_layout \begin_layout Standard Clicking \begin_inset Quotes eld \end_inset Show Track Section \begin_inset Quotes erd \end_inset brings up another formspec: \end_layout \begin_layout Standard \begin_inset Graphics filename lyx_img/Bildschirmfoto_2018-08-30_14-28-32.png width 5cm \end_inset \end_layout \begin_layout Standard On the top, you see a list of all TCBs that border this track section. In your case, there should be two TCBs listed. If there's only one, head over to \begin_inset CommandInset ref LatexCommand ref reference "subsec:Long-track-sections," \end_inset . You should now select a name for the track section, to identify it later. \end_layout \begin_layout Standard The same procedure is applicable when you create a turnout track section, except that you have to set up three or more TCBs. \end_layout \begin_layout Standard The AdvTrains interlocking system allows you to add more TCBs after you have created a track section. This works without problems in most cases. For example, you can easily insert a turnout into an already set-up track section and create another TCB behind it, and AdvTrains will automatically detect the existing track section. Problems arise only if you try to insert a TCB in-between a section, in which case both sides of the TCB will end up assigned to the same section. The code currently does not handle this case properly, so try to avoid this situation by all means. As a last resort, you can always dissolve a faulty track section, as described in the next chapter. \end_layout \begin_layout Subsection Long track sections, crossings and other edge cases \begin_inset CommandInset label LatexCommand label name "subsec:Long-track-sections," \end_inset \end_layout \begin_layout Subsubsection Very long track sections \end_layout \begin_layout Standard If you try to set up a track section that is longer than 1000 nodes, advtrains won't recognize the TCB at the other end because of a safety limit in the traverser function, which is supposed to prevent deadlocks. This case has happened when the Track Section overview screen only shows one TCB in the list. The procedure for this is as follows: \end_layout \begin_layout Enumerate Go to the second TCB (the one that wasn't recognized). It should show \begin_inset Quotes eld \end_inset End of Interlocking \begin_inset Quotes erd \end_inset on the relevant side. \end_layout \begin_layout Enumerate Click \begin_inset Quotes eld \end_inset Create interlocked track section \begin_inset Quotes erd \end_inset . The section created will be different from the one that is already present. \end_layout \begin_layout Enumerate In the track section overview, click \begin_inset Quotes eld \end_inset Join into other section \begin_inset Quotes erd \end_inset \end_layout \begin_layout Enumerate Go back to the first TCB, bring up the Track Section overview screen of the first track section and click \begin_inset Quotes eld \end_inset Join with ??? \begin_inset Quotes erd \end_inset \end_layout \begin_layout Standard The other, missing TCB should now appear in the list. If you accidentally started such a joining procedure, click the \begin_inset Quotes eld \end_inset X \begin_inset Quotes erd \end_inset button on the right. \end_layout \begin_layout Subsubsection Rail crosses \end_layout \begin_layout Standard Since rail crosses are created by laying tracks across each other without logical connection, there's no way for advtrains to know whether rails cross each other. \end_layout \begin_layout Standard Rail crossings in interlocking systems are always one single track section, which in most cases has 4 TCBs adjacent. \end_layout \begin_layout Standard \begin_inset Graphics filename lyx_img/Bildschirmfoto_2018-08-30_14-51-25.png width 5cm \end_inset \end_layout \begin_layout Standard The procedure is quite similar to the one for long sections: First, create two track sections for the branches, and then use the \begin_inset Quotes eld \end_inset Join \begin_inset Quotes erd \end_inset function to merge both sections into one. \end_layout \begin_layout Subsubsection Deleting and re-adding single TCBs to a section \end_layout \begin_layout Standard In some occasions, for example when you remove a siding or a crossover, it can be necessary to unassign a TCB from a track section. There are multiple ways to do this: \end_layout \begin_layout Itemize In the TCB form, click the \begin_inset Quotes eld \end_inset Remove from section \begin_inset Quotes erd \end_inset button \end_layout \begin_layout Itemize In the track section form, first select the TCB in the list and then click \begin_inset Quotes eld \end_inset Unlink selected TCB \begin_inset Quotes erd \end_inset \end_layout \begin_layout Standard The result is that the TCB shows \begin_inset Quotes eld \end_inset End of Interlocking \begin_inset Quotes erd \end_inset and the section does not list the TCB as an endpoint anymore. \end_layout \begin_layout Standard The other case is adding a siding or a crossover, in which case one or more TCBs still show \begin_inset Quotes eld \end_inset End of Interlocking \begin_inset Quotes erd \end_inset although they should be part of a section: \end_layout \begin_layout Itemize Go to another TCB that is registered in the track section and click \begin_inset Quotes eld \end_inset Update near TCBs \begin_inset Quotes erd \end_inset \end_layout \begin_layout Itemize If that did not work, follow the procedure of creating a long track section \end_layout \begin_layout Subsubsection Dissolving sections \end_layout \begin_layout Standard If you made a mistake setting up something and you don't see any other way to fix a misconfigured track section, you can always delete it using the \begin_inset Quotes eld \end_inset Dissolve section \begin_inset Quotes erd \end_inset button. This operation removes the track section and sets all TCBs that previously belonged to the section as \begin_inset Quotes eld \end_inset End of Interlocking \begin_inset Quotes erd \end_inset . This will always work and lets you start over new with setting up track sections. \end_layout \begin_layout Subsection Interlocking patterns \end_layout \begin_layout Standard This section shows some examples on how you should set up track sections on certain track configurations. \end_layout \begin_layout Section Signals and routes \end_layout \begin_layout Standard The purpose of signals is to inform trains about whether they can proceed into the next section safely. Making a section of track safe to pass for a train, turnouts need to be set to the correct position and no other train should be allowed to cross or share parts of the route with this train. \end_layout \begin_layout Subsection Assigning Signals to TCBs \end_layout \begin_layout Standard Signals in the advtrains interlocking system are positioned - like in real life - at the border of track sections. \end_layout \begin_layout Standard When you set up a signal, do the following steps: \end_layout \begin_layout Enumerate If not already happened, set up a TCB (you don't need to, but are advised to, configure track sections there) \end_layout \begin_layout Enumerate Place the signal a few meters in front of the TCB, so that trains stopping at the signal do never pass the TCB \end_layout \begin_layout Enumerate Locate the side of the TCB which points in the direction that trains will proceed past the signal, as shown in the figure below. \end_layout \begin_layout Enumerate Right-click the TCB, and click \begin_inset Quotes eld \end_inset Assign a signal \begin_inset Quotes erd \end_inset on this side. \end_layout \begin_layout Enumerate Punch the signal. \end_layout \begin_layout Standard \begin_inset Graphics filename lyx_img/assign_signal.png width 8cm \end_inset \end_layout \begin_layout Standard You can assign a signal to each side of a TCB. This is, for example, useful when creating block sections on a bi-directional main running line. \end_layout \begin_layout Subsection The concept of routes \end_layout \begin_layout Standard A so-called route is a locked path between two signals, which locks all turnouts in the correct position. \end_layout \begin_layout Standard Example: Imagine a station with 2 platforms on a single track running line. We are looking at signal A. You probably want trains coming from the right to go into platform 1 or into platform 2, so you need to program 2 routes. \end_layout \begin_layout Standard \begin_inset Graphics filename lyx_img/route_ex1.png width 7cm \end_inset \end_layout \begin_layout Standard This leads us to the most important aspect of route programming: Routes always start at a signal (A) and end at a signal facing in the \series bold same direction \series default (D and E), not at an opposite-facing signal (B and C). There are only few exceptions, we'll cover this later. \end_layout \begin_layout Standard When you set a route to make a train proceed on it, the interlocking system ensures that: \end_layout \begin_layout Itemize There are no rail vehicles on the route \end_layout \begin_layout Itemize All turnouts are set to the correct position and it is impossible to move them \end_layout \begin_layout Itemize No other routes can be set that would in any way conflict with this route \end_layout \begin_layout Standard For this to work, you need to specify all track sections the train will pass along, as well as the positions of all turnouts that need to be locked. Those are not only the turnouts that lay directly on the train's route, but also some turnouts on adjacent tracks, the so-called flank protection. \end_layout \begin_layout Standard The purpose of flank protection is to prevent runaway trains and/or wagons to pass into a route. This is achieved by setting nearby turnouts to a position that points \begin_inset Quotes eld \end_inset away \begin_inset Quotes erd \end_inset from the route. Example: \end_layout \begin_layout Standard \begin_inset Graphics filename lyx_img/route_ex2.png width 7cm \end_inset \end_layout \begin_layout Standard The upper turnout, of course, needs to be locked in straight (normal) position, while the lower one is not relevant for the route itself. But what if the lower turnout was set to the diverging (reverse) position and the driver of another train approaching signal B fails to see the red light? This train would crash into the first one. To minimise danger, that other train would need to be routed towards signal D. \end_layout \begin_layout Standard There are, of course, situations, where both positions of a turnout would conflict with a route equally. In those situations, there's nothing you can do and no flank lock needs to be set. \end_layout \begin_layout Subsection Shunt routes \end_layout \begin_layout Standard Operating railways is not all about driving trains around. Coupling, decoupling and moving single engines, wagons or groups of wagons across a station, called shunting, also plays an important role. \end_layout \begin_layout Standard Remember what we said about routes: There must be no rail vehicles on the route. So what if you have some goods wagons ready on a siding, and want to couple an engine to it? You can not set a regular route into the siding, because it is occupied. \end_layout \begin_layout Standard The solution is to program a second route into the siding, but with the difference that it already ends at the rear-facing signal of it, so it doesn't include the siding section itself: \end_layout \begin_layout Standard \begin_inset Graphics filename lyx_img/route_ex3.png width 7cm \end_inset \end_layout \begin_layout Standard The Sht2 route then needs to show a shunt aspect, which instructs the driver to proceed slowly and watch out for vehicles on the route. To show a \begin_inset Quotes eld \end_inset free \begin_inset Quotes erd \end_inset aspect here would be wrong, because that would mean that the track is free until the next main signal, which it is clearly not. \end_layout \begin_layout Standard \shape italic Note that advtrains_interlocking currently does not allow to set individual aspects for routes, this is a feature still to be implemented soon. \end_layout \begin_layout Standard Shunt routes like this are, so far, the only exception to the \begin_inset Quotes eld \end_inset Routes should end at a signal facing the same direction \begin_inset Quotes erd \end_inset rule. \end_layout \begin_layout Subsection Route Release \end_layout \begin_layout Standard In early real-life interlocking systems, routes either had to be cancelled by the signalman after the train had passed the route, or there was a single release contact at the end of the route. However, as interlocking systems evolved and the position of trains is now roughly known by the track sections, portions of the route can be freed as soon as the train has left the corresponding section. \end_layout \begin_layout Standard AdvTrains has chosen a modern approach to route releasing. Each turnout lock is associated to a track section belonging to the route's path. Once the train leaves this section, all assigned locks are also freed. \end_layout \begin_layout Subsection Programming a route \end_layout \begin_layout Standard The route programming procedure is quite straightforward if you've read the previous sections and understood how routes should be set. \end_layout \begin_layout Standard Routes always start at a signal. You must have assigned the signal to a TCB, as described earlier. \end_layout \begin_layout Standard When you right-click the signal, it no longer changes its aspect. Instead, a formspec pops up, showing you an (empty) list of routes with the possibility to set them or to create new routes. Click the \begin_inset Quotes eld \end_inset Create new route \begin_inset Quotes erd \end_inset button to start programming a new route. \end_layout \begin_layout Standard The form closes, and an arrow is displayed on the TCB. You are now in \begin_inset Quotes eld \end_inset Route Programming \begin_inset Quotes erd \end_inset mode, programming the first track section of the route. Now: \end_layout \begin_layout Itemize Put any turnouts you need to lock in the correct position (e.g. by right-clicking them). This includes flank protection. \end_layout \begin_layout Itemize Punch them. This makes a marker saying \begin_inset Quotes eld \end_inset Route Lock Editing \begin_inset Quotes erd \end_inset appear. \end_layout \begin_layout Itemize If you punch a turnout again, or punch the marker, you can remove the lock again. \end_layout \begin_layout Itemize When you've locked all turnouts in the current section, go to and punch the TCB that is the border to the next track section the train proceeds into. \end_layout \begin_layout Standard Once you've done this, the lock markers change to \begin_inset Quotes eld \end_inset Route Lock \begin_inset Quotes erd \end_inset , telling they can't be changed anymore. Repeat the above procedure until you have punched the final TCB, at which the route should end. As mentioned before, there should be a signal at this place, however this is not enforced. Now, run the chat command \family typewriter /at_rp_set \family default to complete programming the route. \end_layout \begin_layout Standard A few hints: \end_layout \begin_layout Itemize If one turnout should be locked by more than one section, set the lock only in the \family typewriter \series bold last \family default \series default of those sections. Locking the same turnout in multiple sections of a single route results in undefined behavior! \end_layout \begin_layout Itemize If you accidentally punched a TCB, you can run \family typewriter /at_rp_back \family default to undo this and return to the previous section. Due to a bug, you have to re-set all locks of this section. \end_layout \begin_layout Itemize If you want to stop programming the entire route without saving it, run \family typewriter /at_rp_discard \end_layout \begin_layout Section Interlocking system operation \end_layout \begin_layout Standard Setting up the interlocking for a portion of a railway network requires some time, experience and planning, but once done, there's not much to do anymore to make trains run on your, now safer, railway. This section covers some useful practices to route trains across your network. \end_layout \begin_layout Standard At the moment, routes can only be set by clicking the signal or via LuaATC, except if you use automatic working. It is planned to control this via the onboard computer and via a \begin_inset Quotes eld \end_inset signal box \begin_inset Quotes erd \end_inset view based on the currently broken itrainmap. \end_layout \begin_layout Subsection Simple route setting and cancelling \end_layout \begin_layout Standard To set a route, simply right-click the signal, select a route and click \begin_inset Quotes eld \end_inset set route \begin_inset Quotes erd \end_inset . If there are no conflicts, the signal turns green and the train is allowed to proceed. \end_layout \begin_layout Standard It may be possible that the route can not be set, because one or more other routes conflict with the current one, or a section is blocked. In this case, the signal stays red, and the conflicting item is shown in the formspec. As soon as the conflict is resolved (by cancellation or release of the conflicting route, or the section becoming free), the requested route will be set and the signal turns green. \end_layout \begin_layout Standard If a route is either requested or set, it can be cancelled from the signalling formspec. This means that all turnouts and sections are released, and the signal reverts back to red. This of course only works when the train has not passed the signal yet. There is no mechanism for Approach Locking. \end_layout \begin_layout Subsection Automatic Working \end_layout \begin_layout Standard Block signals on main running lines usually only have a single route to set, the one proceeding along the main line. Their purpose is only to show whether there are trains in the next section. So, it would be convenient if this only route would set itself again after a train passed. \end_layout \begin_layout Standard This is what Automatic Working is for. Set a route, click \begin_inset Quotes eld \end_inset Enable Automatic Working \begin_inset Quotes erd \end_inset , and as soon as a train passes, the route is automatically re-set. \end_layout \begin_layout Standard This function is nearly identical to SimSig automatic signals. It can also be useful on a line with high traffic, when there's a low-frequente d access to a siding. You'd enable automatic working for the main route and cancel it only when you need a train to go into the siding. \end_layout \end_body \end_document