I have attempted to create a schematic drawing of the track layout between Bad Aibling and Kolbermoor:
I have based my drawing on these cab-ride videos:
-
Bad Aibling to Kolbermoor (29:00 to 36:30)
-
Kolbermoor to Bad Aibling (03:00 to 10:30)
Please note that there are a few foot crossings which I have not drawn on this map as they are not protected by a signal. Also, the drawing is not to scale.
About the infrastructure:
- Axle counters are used for train detection.
- All main signals on this track have a Zs1 alongsides them.
- The signals at 28.7 and 29.4 are automatic block signals, and are connected to the level crossing at 28.8.
- In Germany, main signals are usually placed a bit before the start of a block or danger point, this allows trains to come to a full stop before reaching the point of danger.
- I suspect the block division to be located somewhere between 28.8 and 29.2.
This is what we know so far:
- The timetable of both trains:
Code:
+--------------+-----------+-----------+
| Train nr. | 79505 | 79506 |
| Direction | -> Kmoor | <- B. A. |
+--------------+-----------+-----------+
| Bad Aibling | 06:38 | 06:51 |
| B.A. Kurpark | 06:40 | 06:48 |
| Kolbermoor | 06:44 | 06:45 |
+--------------+-----------+-----------+
- The trains are scheduled to meet each other at Kolbermoor. The westbound train has a 5 minute stop there to allow the eastbound train to pass.
- The eastbound train was delayed by approximately 4 minutes, the westbound train was running according to schedule.
- The eastbound train was supposed to remain at Bad Aibling, to prevent the westbound train from getting delayed as well.
- At Bad Aibling, both trains use platform 1 at this time of day.
Here is what I think what has happened:
- At 6:43, the eastbound train left Bad Aibling, after being given a Zs1. As both trains were planned to use platform 1, this could explain why the driver did not notice anything unusual as the points in front of him would have already been pointing in the right direction.
- After a short stop at B.A. Kurpark, the eastbound train resumed its journey at 6:45.
- At 6:45, the westbound train left Kolbermoor according to schedule.
- When both trains initiated their departure, the block inbetween them was empty. The westbound train got a proceed aspect according to the timetable, the eastbound train got a proceed aspect because the next block was still empty.
- Both trains went past the main signals before the opposite train had entered the block beyond it.
- After leaving B.A. Kurpark, there were no more signals to alert the driver of the eastbound train of any oncoming trains.
- The driver of the westbound train could have been warned by the distant signal at 30.5, but as the associated main signal guards a level crossing it would not be unusual for this distant signal to show a 'caution' aspect.
- At 30.3km both trains collided head-on, without having seen eachother due to the curvy nature of the track.
* Source:
Tagesspiegel