21.07.2013 / Välillä Rekola–Korso
21.07.2013 Sm5 N train going 160 km/h. You may ask why such a speed at this line? - Because train skipped all stops between Tikkurila and Kerava. May be because of Ringbana construction.
Kommentit
| 21.07.2013 02:48 | [Tunnus poistettu]: | Syy on oikea, eli kolmena viikonloppuna ajaa N-junat la klo 19-n. 23 ja sunnuntaisin Keravan suuntaan suoraan Tikkurilasta Keravalle pysähtymättä väliasemille. | |
| 21.07.2013 09:20 | Ari Palin: | Also I tried to take this kind of picture but unhappily the screens in the train leaving Helsinki at 18.41 were empty. Only the data in the grey area was shown. So the speed information was available but nobody can see if the train is the N train or some other train. | |
| 21.07.2013 12:53 | Martin Hillebard: | It looks like a standard behaviour, that the driver lets the speed accelerate to maximum between halts whenever possible. Thus if You, say, visit the Hyvinge museum with Helsinki as starting point, and ride R train, she will travel at 157..158 something for a while before beginning to decelerate again, for the next station. This to both directions despite the track geometry. There must be an automatic top velocity limiting device: I have never seen 160 kph being exceeded, given that the above shown display is trustworthy. |
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| 21.07.2013 13:06 | Topi Lajunen: | The Sm4 (like most modern) trains have "speed setting", which is a kind of like the cruise control found in automobiles. They cut the traction when the set speed is reached - not abruptly, but gradually. Latest trains can also do a regenerative braking automatically if the speed exceeds the speed setting - for example on a downhill grade. The maximum setting for class Sm4 is 160 km/h, but often this means an actual speed of around 158 km/h. |
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| 22.07.2013 20:42 | Kimmo T. Lumirae: | It all depends on the timetable, Martin. On densily and frequently stopping trains, say, halt distances of 2 kms, the normal behaviour is to make rapid acceleration from 0 to 80 (30 seconds or so) , then put the traction off and let the train roll on idle (maybe a minute or so) and make a tight braking to the halt: this leaves maybe 15-30 seconds to stay on the station on 2-minute intervals between departure times, and then all again from the start. It is not very energy efficient to try to get as high speed as possible between the stations, if it is not necessary or forced to do so because of the tight timetable or running late. |