xc hst violent jurking?

hst2cornwall · 27 Jan 2012

Right this is my 1st time on this forum and I'm not sure if I'm posting in the correct section but here goes.
A couple of week ago I was on an XC Hst from cheltenham spa to exeter to catch the FGW direct to Truro. The XC was running nearly an hour late and on leaving Taunton it starting some extreme jurking and jolting. Have often got this slightly on an hst when the rear power car is taking up any slack but always at very low speeds after leaving the station, but this must have been at over 50 mph, no explanation on why the xc service was running late, could it have been a fault with the rear power car? Or do you think the driver was giving it too much power too soon? Quite a few passengers were commenting on how violent the motion was.

Any thoughts people?
Thanks in advance

RailUK Forums

hello · 27 Jan 2012

was it raining?

DaveNewcastle · 27 Jan 2012

or in the Autumn (leaf-fall) ?

hst2cornwall · 27 Jan 2012

Thanks for the reply not raining and on a section of line with no adjacent trees so I would of thought wheel slip unlikely?

4SRKT · 27 Jan 2012

Was there a very over-excited HST Basher in the toilet?

Crossover · 27 Jan 2012

I have experienced a surging XC HST before - from Sheffield up to Leeds - rather annoying I have to say (a surging Voyager is an even stranger experience, though!)

Schnellzug · 27 Jan 2012

probably the driver. Some of those CrossCountry drivers are dreadful.

( :lol:

)
--- old post above --- --- new post below ---
Actually, on a more serious note, it can do that if the wheelslide protection system cuts in under braking.

hello · 27 Jan 2012

was it raining?

83G/84D · 27 Jan 2012

Could have been wheelslip, what were the conditions? If there was rain or frost this might have been a contributary factor. Trains departing Taunton in the down direction do not normally suffer the effects you describe in good weather unless there is an issue with the traction.

HST's do suffer from the jolting and jerking you describe especially when starting away on a rising gradient.

Totnes (down), St Germans (down), Truro (down), St Erth (down), Bodmin Parkway (up) are some places I have noticed it, usually when rails are wet after rain.

Old Timer · 27 Jan 2012

Because the rear power car runs at at faster speed than the front, when the power controller is opened there is a slight mismatch between the front and rear as the rear engine speed dips, which is amplified if the power controller is opened sharply.

I know this came up in the early days of HST operation on the ECML, and it settled down when Drivers started to power up slowly from a start. If you can find an old recording you will hear the slight pause from initial power to opening up the controller progressively.

<iframe width="960" height="720" src="https://www.youtube.com/embed/8q2o7QUzY6k" frameborder="0" allowfullscreen></iframe>

hst2cornwall · 27 Jan 2012

It was accellerating not braking at the time, i don't know how the two power cars are synchronised on an hst, is it ecu controlled so that the rear power car isn't giving more than the lead? or is the driver incharge of that?

PaxVobiscum · 28 Feb 2012

4SRKT said:
Was there a very over-excited HST Basher in the toilet?

Ho ho ho

(led to this thread from http://www.railforums.co.uk/showthread.php?t=60973)

David · 28 Feb 2012

Old Timer said:
<iframe width="960" height="720" src="https://www.youtube.com/embed/8q2o7QUzY6k" frameborder="0" allowfullscreen></iframe>

I'll call you and raise you ....

How to notch up from a standing start (including the cooling group giving it the full air raid siren treatment).

https://www.youtube.com/watch?v=C1ICcOu0NkM

(PS. Crank up the volume and enjoy!)

deltic1989 · 28 Feb 2012

4SRKT said:
Was there a very over-excited HST Basher in the toilet?

Don't joke about that. I saw that once when they forgot to lock the door. What has been seen cannot be unseen

hock:

on an unrelated note:

let he who have understanding reckon the number of the beast for it is a human number, it is six hundred three score and six.

This is my 666th post.

hst2cornwall · 29 Feb 2012

I'm now thinking from some of the posts on here it was a case of an XC driver trying to make up time on the starts. It was funny that the FGW manager kept saying sorry for the rather low rate of knots we were making between exeter where we joined, and Plymouth where the XC terminated. "This is due to an extremely late running crosscountry service infront of us" funny! Love that Valenta Sunset clip too, seen it loads and miss them, it will be a shame when the hst's are no more, lets hope the voyager plague doesn't spread to FGW please?

TDK · 29 Feb 2012

deleted post - sorry

hst2cornwall · 29 Feb 2012

So let me get this straight, the hst applies power to the traction motors in notches but the class 220/221 voyager is basically power on off? I thought they basically all worked the same in terms of a diesel engine running a generator/alternator to provide power to the traction motors? I know dmu's are automatically geared and I pressume voyagers are the same? The XC that seemed to be slipping was an hst edenburough to plymouth I think by the way.

redthunder · 29 Feb 2012

could be mixture of the conditions and the driving but give me a hst compared to a 220 or 221 anyday

the worst violent jerkings I tend to experience on a train is the class 185's going over the pennines between Leeds & Manchester, very nasty they are!!!!

TDK · 1 Mar 2012

hst2cornwall said:
So let me get this straight, the hst applies power to the traction motors in notches but the class 220/221 voyager is basically power on off? I thought they basically all worked the same in terms of a diesel engine running a generator/alternator to provide power to the traction motors? I know dmu's are automatically geared and I pressume voyagers are the same? The XC that seemed to be slipping was an hst edenburough to plymouth I think by the way.

When applying power with a diesel engine driving traction motors the power (BHP) will peak in each notch, if you have an ammeter in the cab it is best to notch up once the ammeter peaks and then starts to drop slightly, this way you are driving the train more economically and also more professionally, in the class 67 you have a computer screen on the EM2000 interface that shows you the BHP being delivered in each notch the BHP and notches for a 67 are below - hope this helps with any doubts on electro diesels. I wouls imagine that to drive an HST, Voayger would be ultimately best if you adhered to these guidlines.

Notch 1 - 260
Notch 2 - 440
Notch 3 - 650
Notch 4 - 990
Notch 5 - 1250
Notch 6 - 1550
Notch 7 - 2350
Notch 9 - 3050

These are approximate

hst2cornwall · 1 Mar 2012

TDK said:
When applying power with a diesel engine driving traction motors the power (BHP) will peak in each notch, if you have an ammeter in the cab it is best to notch up once the ammeter peaks and then starts to drop slightly, this way you are driving the train more economically and also more professionally, in the class 67 you have a computer screen on the EM2000 interface that shows you the BHP being delivered in each notch the BHP and notches for a 67 are below - hope this helps with any doubts on electro diesels. I wouls imagine that to drive an HST, Voayger would be ultimately best if you adhered to these guidlines.

Notch 1 - 260
Notch 2 - 440
Notch 3 - 650
Notch 4 - 990
Notch 5 - 1250
Notch 6 - 1550
Notch 7 - 2350
Notch 9 - 3050

These are approximate

Thanks for the info, all this is really interesting I've love to be able to get to grips with a train SIM but I'm partially sighted and just can't use them.

TDK · 3 Mar 2012

hst2cornwall said:
Thanks for the info, all this is really interesting I've love to be able to get to grips with a train SIM but I'm partially sighted and just can't use them.

I don't do train sims - I drive the locos - however it's a shame with the poor sight you have, I have never done a train sim except the professional ones in training.

xc hst violent jurking?

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