Is that an easter egg? (SG2, MG2 groaning sound)

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brozma
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Is that an easter egg? (SG2, MG2 groaning sound)

Post by brozma » 15 Jun 2015, 20:24

Hello everyone, one day I was having fun with SG2 on simvliet haven bridge loop track. I let it run in circles, then when I stopped the SG2 and wanted to leave it there staying I heard very loud groaning. It played for some seconds and then it cutted off and I could heard normal muted humming (when the train is powered from overhead wire or third rail and it's staying, you can hear a muted humming) I was wondering, "Why SG2 made that loud groaning? Wasn't that a system important for SG2? Why this groaning only sounds when the train is powered from overhead wire or third rail? Why only SG2 and MG2 (I discovered that MG2 does it too) make this sound?

For Michiel: I think, I dicovered an easter egg! 8-)
If you want to make a very fast ride, just disable ATB/ZUB, put trottle to 1.00 and enjoy.
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Sorry for my bad English. I am Czech and i am learning English

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senjer
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Re: Is that an easter egg? (SG2, MG2 groaning sound)

Post by senjer » 15 Jun 2015, 20:34

Thats the compressor of the train. They make this sound in real life. Because of that they had install couplers on the buffers at De Akkers.

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metroverslaafde
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Re: Is that an easter egg? (SG2, MG2 groaning sound)

Post by metroverslaafde » 16 Jun 2015, 15:30

Yes, it is a compressor. The doors on real the real MG2/SG2 close bij air pressure produced bij the compressor. To keep the doors closed the compressor needs to build up enough pressure to do so, that declares the sssssssssh noise when you close the doors, that is the airflow.

A video where you can hear the sound quite clearly:

https://www.youtube.com/watch?v=kviUHG_BXDk

atimur
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Re: Is that an easter egg? (SG2, MG2 groaning sound)

Post by atimur » 16 Jun 2015, 20:50

metroverslaafde wrote:Yes, it is a compressor. The doors on real the real MG2/SG2 close bij air pressure produced bij the compressor. To keep the doors closed the compressor needs to build up enough pressure to do so, that declares the sssssssssh noise when you close the doors, that is the airflow.

A video where you can hear the sound quite clearly:

https://www.youtube.com/watch?v=kviUHG_BXDk
Also pressured air is used for brakes, that's the source of hissing sound when releasing them.


atimur
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Re: Is that an easter egg? (SG2, MG2 groaning sound)

Post by atimur » 17 Jun 2015, 08:26

metroverslaafde wrote:True, I forgot about that :)
Actually, it's the main use of compressed air, doors is only a side job. :)

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Michiel
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Re: Is that an easter egg? (SG2, MG2 groaning sound)

Post by Michiel » 17 Jun 2015, 15:00

Actually these trains use electrodynamic braking by default, air brakes are only used at low speeds when the ED-brake is not efficient any more. And also the pantograph and third rail shoes are controlled by compressed air. This is the biggest loophole for these trains, if the air pressure is to low you have no power, and without power you cannot start the compressor to increase the air pressure. When this happens the trains requires 'CPR' to either manually supply it with power (the pole of the red flag below the third rail shoe does the trick, although I doubt it's very safe) or manually supply it with compressed air (basically using a big foot pomp) in order to get it up and running again.

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MG2
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Re: Is that an easter egg? (SG2, MG2 groaning sound)

Post by MG2 » 17 Jun 2015, 17:05

Michiel wrote:When this happens the trains requires 'CPR' to either manually supply it with power (the pole of the red flag below the third rail shoe does the trick, although I doubt it's very safe) or manually supply it with compressed air (basically using a big foot pomp) in order to get it up and running again.
I had to do that a number of times. But it's a failure and shouldn't happen too often :mrgreen:

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Maronit
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Re: Is that an easter egg? (SG2, MG2 groaning sound)

Post by Maronit » 17 Jun 2015, 19:28

atimur wrote: doors is only a side job. :)
Pun Intended?
Glasgow underground FTW, the london one is nice too.
heb inmiddels gehoorschade volgens mij, vanwege vierkante wielen in de sim. -2.00 FTW :lol:

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brozma
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Re: Is that an easter egg? (SG2, MG2 groaning sound)

Post by brozma » 18 Jun 2015, 14:10

Michiel wrote: When this happens the trains requires 'CPR' to either manually supply it with power
What is CPR? It's something like APU (auxiliary power unit) in aircrafts? Don't be surprised, I'm asking like that. I never have been in Netherlands and I'm not an engineer.

And Michiel: That's not an easter egg! I thought it is, but people here corrected me !
If you want to make a very fast ride, just disable ATB/ZUB, put trottle to 1.00 and enjoy.
In my Avatar is a Logo of a Prague metro.
Sorry for my bad English. I am Czech and i am learning English

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