1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
|
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
"http://www.w3.org/TR/html4/loose.dtd">
<html >
<head><title></title>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
<meta name="generator" content="TeX4ht (http://www.tug.org/tex4ht/)">
<meta name="originator" content="TeX4ht (http://www.tug.org/tex4ht/)">
<!-- html -->
<meta name="src" content="interlocking.tex">
<link rel="stylesheet" type="text/css" href="interlocking.css">
</head><body
>
<!--l. 18--><p class="noindent" >
<!--l. 18--><p class="noindent" ><span
class="ecsx-1728">Interlocking</span>
<span
class="ecsx-1728">System</span>
<span
class="ecsx-1728">Guide</span>
<div class="tabular"> <table id="TBL-1" class="tabular"
cellspacing="0" cellpadding="0"
><colgroup id="TBL-1-1g"><col
id="TBL-1-1"></colgroup><tr
style="vertical-align:baseline;" id="TBL-1-1-"><td style="white-space:nowrap; text-align:left;" id="TBL-1-1-1"
class="td00"></td></tr></table>
</div>
<a
id="x1-2r1"></a>
<!--l. 20--><p class="noindent" ><span
class="ecsx-1200">1</span> <span
class="ecsx-1200">Introduction</span>
<a
id="Q1-1-0"></a>
<!--l. 22--><p class="noindent" >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
“railway interlocking” on the internet.
<!--l. 28--><p class="noindent" >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 “Proceed”. 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.
<!--l. 37--><p class="noindent" >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.
<!--l. 42--><p class="noindent" >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.
<!--l. 46--><p class="noindent" >If you are looking for a place to learn how real-world interlocking systems work, have a look at “SimSig”. 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.
<!--l. 52--><p class="noindent" >
<a
id="x1-3r2"></a>
<!--l. 52--><p class="noindent" ><span
class="ecsx-1200">2</span> <span
class="ecsx-1200">Setting</span>
<span
class="ecsx-1200">up</span>
<span
class="ecsx-1200">track</span>
<span
class="ecsx-1200">sections</span>
<a
id="Q1-1-0"></a>
<!--l. 54--><p class="noindent" >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.
<!--l. 59--><p class="noindent" >A track section often covers:
<ul class="itemize1">
<li class="itemize">A section on a main running line, between two signals
</li>
<li class="itemize">A single turnout
</li>
<li class="itemize">A rail crossing, or a set of turnouts acting as a double/single slip switch
</li>
<li class="itemize">A siding</li></ul>
<!--l. 67--><p class="noindent" >You will find some examples on how to interlock certain patterns later.
<!--l. 69--><p class="noindent" >
<a
id="x1-4r1"></a>
<!--l. 69--><p class="noindent" ><span
class="ecsx-1200">2.1</span> <span
class="ecsx-1200">Track</span>
<span
class="ecsx-1200">Circuit</span>
<span
class="ecsx-1200">Breaks</span>
<a
id="Q1-1-0"></a>
<!--l. 71--><p class="noindent" >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.
<!--l. 75--><p class="noindent" >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.
<!--l. 79--><p class="noindent" >Setting up a TCB works as follows:
<ol class="enumerate1" >
<li
class="enumerate" id="x1-6x1">Place a TCB node somewhere near the place where the circuit break is going to be located.
</li>
<li
class="enumerate" id="x1-8x2">Right-click the TCB node
</li>
<li
class="enumerate" id="x1-10x3">Punch the rail which should act as TCB</li></ol>
<!--l. 86--><p class="noindent" >The result should look like this:
<!--l. 88--><p class="noindent" ><img
src="0_home_moritz_Home_Projekte_Minetest_minetest_m___s_assets_lyx_img_screenshot_20180830_142551.png" alt="PIC"
>
<!--l. 90--><p class="noindent" >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:
<!--l. 93--><p class="noindent" ><img
src="1_home_moritz_Home_Projekte_Minetest_minetest_m____lyx_img_Bildschirmfoto_2018-08-30_14-26-35.png" alt="PIC"
>
<!--l. 95--><p class="noindent" >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 “End of
interlocking”. This means that there is no track section set up at this place.
<!--l. 101--><p class="noindent" >You should repeat this procedure once again a few meters away from the first TCB to create a second TCB on the same
track.
<!--l. 104--><p class="noindent" ><img
src="2_home_moritz_Home_Projekte_Minetest_minetest_m____lyx_img_Bildschirmfoto_2018-08-30_14-32-48.png" alt="PIC"
>
<!--l. 106--><p class="noindent" >Once you have both bordering TCBs set up, you can now create the actual track section. To do this:
<ol class="enumerate1" >
<li
class="enumerate" id="x1-12x1">Right-click one of the TCBs
</li>
<li
class="enumerate" id="x1-14x2">Locate the correct side (A or B) to create the track section
</li>
<li
class="enumerate" id="x1-16x3">Click “Create interlocked Track Section” in the formspec on the chosen side.</li></ol>
<!--l. 114--><p class="noindent" >Now, the text on the formspec has changed. It shows something like this:
<!--l. 117--><p class="noindent" ><img
src="3_home_moritz_Home_Projekte_Minetest_minetest_m____lyx_img_Bildschirmfoto_2018-08-30_14-27-25.png" alt="PIC"
>
<!--l. 119--><p class="noindent" >Clicking “Show Track Section” brings up another formspec:
<!--l. 121--><p class="noindent" ><img
src="4_home_moritz_Home_Projekte_Minetest_minetest_m____lyx_img_Bildschirmfoto_2018-08-30_14-28-32.png" alt="PIC"
>
<!--l. 123--><p class="noindent" >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 <a
href="#x1-17r2">2.2<!--tex4ht:ref: subsec:Long-track-sections, --></a>. You should now select a name for the track section, to identify it later.
<!--l. 128--><p class="noindent" >The same procedure is applicable when you create a turnout track section, except that you have to set up three or more
TCBs.
<!--l. 131--><p class="noindent" >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.
<!--l. 142--><p class="noindent" >
<a
id="x1-17r2"></a>
<!--l. 142--><p class="noindent" ><span
class="ecsx-1200">2.2</span> <span
class="ecsx-1200">Long</span>
<span
class="ecsx-1200">track</span>
<span
class="ecsx-1200">sections,</span>
<span
class="ecsx-1200">crossings</span>
<span
class="ecsx-1200">and</span>
<span
class="ecsx-1200">other</span>
<span
class="ecsx-1200">edge</span>
<span
class="ecsx-1200">cases</span>
<a
id="Q1-1-0"></a>
<!--l. 144--><p class="noindent" >
<a
id="x1-18r1"></a>
<!--l. 144--><p class="noindent" ><span
class="ecsx-1000">2.2.1</span> <span
class="ecsx-1000">Very</span>
<span
class="ecsx-1000">long</span>
<span
class="ecsx-1000">track</span>
<span
class="ecsx-1000">sections</span>
<a
id="Q1-1-0"></a>
<!--l. 146--><p class="noindent" >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:
<ol class="enumerate1" >
<li
class="enumerate" id="x1-20x1">Go to the second TCB (the one that wasn’t recognized). It should show “End of Interlocking” on the relevant side.
</li>
<li
|