Voyagers idling at Stations

[heart-of-wessex]

Hi all,

I was just wondering as I've noticed at stations, Voyagers seem to, upon preparing for departure, sound different.

ie most the time you get the normal departure where you hear the guard sending 3 beats to the driver to close the doors, who then sends 3 beats back to acknowledge, the engine goes from the idling tone to a slightly higher tone like vvvvvvvrrrrooooommmmm. But this seems to happen at different times or not at all and simply goes up when leaving.

What actually makes it do this? does the driver have it in notch 1 (i know they are combined power handles but could still have it in neutral) or maybe it does it when its put in forward?


thanks,
James.

 

[voyagerdude220]

I've allways wondered this myself, but it's not happened on any of the many Voyagers i've been on for quite a long time.

How can drivers slightly apply the throttle , when the doors are still open/closing?

Also Voyager related-

Around Christmas time, I took a trip on 221129 between Preston and Somerset, and noticed that everytime we arrived into a station as usual, the engines didn't idle- They kept reving for some reason.

This only happened between Preston & Birmingham, with the first driver, and not after the new train crew go on at New Street.


When drivers log into the TMS system on a Voyager, why do the engines rev slightly a few times? I've seen this happen from infront of a Voyager, and noticed that the driver wasn't even touching the multi throttle-brake controller.

 

[Kris]

I wonder if they have a form of 'compressor speed up' system to provide air - e.g. the engine revs higher to get the compressors to pump more air into the system as required?

 

[Tom]

Remember that Voyagers are diesel electric, ie, the engines provide the power for when the train requires it, not necessarily for movement.

 

[Jordy]

I know it isn't, but it sounds like they turn it from neutral 'into gear' ready to leave if you see what I mean...

Around Christmas time, I took a trip on 221129 between Preston and Somerset, and noticed that everytime we arrived into a station as usual, the engines didn't idle- They kept reving for some reason.

This also happens on a certain 185, it idles, then revs up, then down, then idles, etc. Dunno why though!

Jordy

 

[Kris]

Remember that Voyagers are diesel electric, ie, the engines provide the power for when the train requires it, not necessarily for movement.

Didn't know that. I thought they were just noisy DMU's ......... a lot noisier than the 159's but not bad inside noisewise.

 

[Guinness]

I was under the impression that they are needed to the Electrics going. Voyagers do use a lot of electricity and they can easily put a strain on battery resources, so higher 'revving' them will boost the output of the Generators.

Compressors work directly off the Electricity IIRC.

 

[westcoaster]

ona dessie there is a red button on the combined power handle, that you hold in, when you release the brake, but holds it on and you only release when you feel the train taking power, to stop you rolling back, this might be the reason.

 

[332 > 444]

I know it isn't, but it sounds like they turn it from neutral 'into gear' ready to leave if you see what I mean...



This also happens on a certain 185, it idles, then revs up, then down, then idles, etc. Dunno why though!

Jordy

Ive read somewhere that the 185s and Voyagers have similar (or same) engines despite the latter being DEMU.

 

[Guinness]

Ive read somewhere that the 185s and Voyagers have similar (or same) engines despite the latter being DEMU.

Both Cummins engines IIRC.

 

[Donny Dave]

Yup. Cummins QSK19. 180s have the same engine as well.

 

[Darandio]

Took note of this and had a listen today. Only happened once when I heard the engine rev up and I thought it was ready for the off. On closer inspection the guard was still on the platform so it must have been this.

 

[nath9425]

This has happened to me a few times. While standing on station platforms watching them come through usually the doors close then they tend to have the vrooom start then the guard closes his door then bang the train departs! I reckon they put it in F1 because the train is so heavy it wont move, this is just to get the engine going again then they put into F5 but that is only a therory! Voyagers baffle me sometimes!

 

[Darandio]

They baffle me too but I don't really care. All they remind me of is HST's sat with weeds growing around them in storage.

 

[O L Leigh]

Remember that Voyagers are diesel electric, ie, the engines provide the power for when the train requires it, not necessarily for movement.

There's your answer.

Station stops can provide quite a strain on a unit. There's the power operated doors, the A/C running up to compensate for external doors being opened and the controlled environment being lost, and the compressor(s) replacing air lost in braking and for the suspension to adjust to the changing load. All of these things happen automatically without traincrew intervention and, if battery power dips below a certain level or systems that run directly from the alternator are required to be run, the engine management system will have to raise the engine revs to compensate. It certainly isn't anything to do with the driver, as he/she won't be able to take power until he/she gets interlock when all the doors are actually closed.

The button on the power/brake handle is a hill-start mechanism which allows the unit to start away while holding a step 1 brake application until the train is rolling. It makes up for not having a seperate brake lever. As it is only used when the unit is ready to roll, it wouldn't be responsible for the sounds heard.

one TN

 

[ChrisCooper]

I'm pretty sure it happens when the drivers puts the master switch (or whatever it's called on modern units) to forward from neutral. This has nothing to do with the interlocking, and can be done at any time, and they can be left in forward all the time, but placing it in neutral allows the driver to take their foot off the DSD, and shuts down the vigilance system. The auxiliary loads can all be handled with the engines at idle, the engine management system will just increase fuel flow to maintain the revs under extra load, but their won't be a noticable change in engine note (I've not noticed it on Voyagers, but on some trains like Turbostars, when the A/C comes on their is a slight dip in revs before they return to normal, both due to the power spike as the A/C starts up, and the delay in the EMS compensating for the extra load, but after that they idle just the same as before). I presume that at the slow idle, they can't provide enough voltage for traction purposes, and revving up when selecting forward gives time for the engine to be at fast idle before the contactors are closed to supply power to the motors.

 

[thefab444]

They baffle me too but I don't really care. All they remind me of is HST's sat with weeds growing around them in storage.

Why? Not many in storage, most of them are being used, well the ones that can be.

 

[Darandio]

Why? Not many in storage, most of them are being used, well the ones that can be.

But there are some in storage though, how many, i don't know personally, somebody can maybe enlighten me.