Eurostar train gets stuck in Channel Tunnel

[Boltar]

On Sep 24, 10:38 am, Ar <A...@127.0.0.1> wrote:
> "The driver detected that it was a problem relating to the pantograph -
> the device on the top of the train which draws power from the overhead
> lines.

A eurostar has 2 25Kv pantographs - one on each power car and AFAIK
only uses one at a time. Why couldn't he just switch it to the other
one and continue in minutes?

B2003

[Recliner]

"Boltar" <boltar2003**********.uk> wrote in message
news:ad71e924-338d-4a8c-852a-c0c3e3e6afe7@k13g2000hse.************.com
> On Sep 24, 10:38 am, Ar <A...@127.0.0.1> wrote:
>> "The driver detected that it was a problem relating to the
>> pantograph - the device on the top of the train which draws power
>> from the overhead lines.
>
> A eurostar has 2 25Kv pantographs - one on each power car and AFAIK
> only uses one at a time. Why couldn't he just switch it to the other
> one and continue in minutes?

I thought both pantographs were in use all the time -- a Eurostar train
consists of two semi-independent half-sets. Each pantograph provides the
juice for the three powered bogies at each end of the train.

[Mizter T]

On 24 Sep, 10:52, Boltar <boltar2...**********.uk> wrote:

> On Sep 24, 10:38 am, Ar <A...@127.0.0.1> wrote:
>
> > "The driver detected that it was a problem relating to the pantograph -
> > the device on the top of the train which draws power from the overhead
> > lines.
>
> A eurostar has 2 25Kv pantographs - one on each power car and AFAIK
> only uses one at a time. Why couldn't he just switch it to the other
> one and continue in minutes?
>

No, on a Eurostar both pantographs are in use at the same time, and
because of safety concerns in the chunnel there is no high voltage bus
line along the train that links a pantograph on one end of the train
to the power car on the other end (unlike on a TGV).

That said, I understand one E* power car is powerful enough to propel
a whole Eurostar train set. What I don't know is whether a E* power
car at the rear of a train is able to push that train, or whether it
can only pull it. If it can push it (with the failed powercar acting
as a kind of DVT), then perhaps that's exactly what happened in this
instance?

[Recliner]

"Mizter T" <mizter.t@**********> wrote in message
news:a7fd4512-f4cf-48f8-b0b8-dfbfd570a239@m44g2000hsc.************.com
> On 24 Sep, 10:52, Boltar <boltar2...**********.uk> wrote:
>
>> On Sep 24, 10:38 am, Ar <A...@127.0.0.1> wrote:
>>
>>> "The driver detected that it was a problem relating to the
>>> pantograph - the device on the top of the train which draws power
>>> from the overhead lines.
>>
>> A eurostar has 2 25Kv pantographs - one on each power car and AFAIK
>> only uses one at a time. Why couldn't he just switch it to the other
>> one and continue in minutes?
>>
>
> No, on a Eurostar both pantographs are in use at the same time, and
> because of safety concerns in the chunnel there is no high voltage bus
> line along the train that links a pantograph on one end of the train
> to the power car on the other end (unlike on a TGV).
>
> That said, I understand one E* power car is powerful enough to propel
> a whole Eurostar train set. What I don't know is whether a E* power
> car at the rear of a train is able to push that train, or whether it
> can only pull it. If it can push it (with the failed powercar acting
> as a kind of DVT), then perhaps that's exactly what happened in this
> instance?

Presumably the rear power car is always pushing normally anyway, so that
shouldn't be a problem. I imagine that if one pantograph fails, it takes
a certain amount of time for the driver to work out what's wrong, and
then doing some resetting to isolate the failed systems, before he can
start the train again. This must be one of the standard scenarios that's
designed into the train.

[Boltar]

On Sep 24, 11:22 am, Mizter T <mizte...@**********> wrote:
> On 24 Sep, 10:52, Boltar <boltar2...**********.uk> wrote:
>
> > On Sep 24, 10:38 am, Ar <A...@127.0.0.1> wrote:
>
> > > "The driver detected that it was a problem relating to the pantograph -
> > > the device on the top of the train which draws power from the overhead
> > > lines.
>
> > A eurostar has 2 25Kv pantographs - one on each power car and AFAIK
> > only uses one at a time. Why couldn't he just switch it to the other
> > one and continue in minutes?
>
> No, on a Eurostar both pantographs are in use at the same time, and

Ah , didn't realise.

> because of safety concerns in the chunnel there is no high voltage bus

The HSE bed wetters strike again. Though perhaps if that had allowed a
high voltage line along the train but *hadn't* allowed trucks to be
transported in the tunnel then we'd probably be a lot better off.

B203

[Mizter T]

On 24 Sep, 12:22, Boltar <boltar2...**********.uk> wrote:
> On Sep 24, 11:22 am, Mizter T <mizte...@**********> wrote:
>
> > On 24 Sep, 10:52, Boltar <boltar2...**********.uk> wrote:
>
> > > On Sep 24, 10:38 am, Ar <A...@127.0.0.1> wrote:
>
> > > > "The driver detected that it was a problem relating to the pantograph -
> > > > the device on the top of the train which draws power from the overhead
> > > > lines.
>
> > > A eurostar has 2 25Kv pantographs - one on each power car and AFAIK
> > > only uses one at a time. Why couldn't he just switch it to the other
> > > one and continue in minutes?
>
> > No, on a Eurostar both pantographs are in use at the same time, and
>
> Ah , didn't realise.

Only on the Eurostar, mind - the train is so long that any
oscillations on the overhead line induced by the passing of the first
pantograph are considered to have died down sufficiently in time for
the passing of the second pantograph.

>
> > because of safety concerns in the chunnel there is no high voltage bus
>
> The HSE bed wetters strike again. Though perhaps if that had allowed a
> high voltage line along the train but *hadn't* allowed trucks to be
> transported in the tunnel then we'd probably be a lot better off.
>

HSE - pray tell, where do they come into it? Interesting that in the
same paragraph you can then come up with what others might describe as
a health and safety bed wetters solution.

[Steve]

On 24 Sep, 12:38, Mizter T <mizte...@**********> wrote:

> > > No, on a Eurostar both pantographs are in use at the same time, and
>
> > Ah , didn't realise.
>
> Only on the Eurostar, mind - the train is so long that any
> oscillations on the overhead line induced by the passing of the first
> pantograph are considered to have died down sufficiently in time for
> the passing of the second pantograph.
>

A brief calculation suggests the elapsed time between the passage of
the pantographs at full speed is not hugely different between the
Eurostar and the Pendolino:

E* 4.8sec
Pendolino (9 car) 3.9 sec
Pendolino (11 car) 4.8 sec

Admittedly I've taken the train length as the distance between
pantographs for simplicity

Perhaps we might see the lengthened Pendolini running with both pans
up?

Steve Adams

[Boltar]

On Sep 24, 12:38 pm, Mizter T <mizte...@**********> wrote:
> > The HSE bed wetters strike again. Though perhaps if that had allowed a
> > high voltage line along the train but *hadn't* allowed trucks to be
> > transported in the tunnel then we'd probably be a lot better off.
>
> HSE - pray tell, where do they come into it? Interesting that in the

Don't they have the final say over what can and can't go into the
tunnel, at least on the english half anyway?

> same paragraph you can then come up with what others might describe as
> a health and safety bed wetters solution.

I think theres a difference between having an HT cable running along a
train (especially given theres one 3 foot above it anyway!) and
allowing the carrying of flammable cargo in a 20 mile long undersea
tunnel.

B2003

[R.C. Payne]

> On 24 Sep, 12:38, Mizter T <mizte...@**********> wrote:
>
>>>>No, on a Eurostar both pantographs are in use at the same time, and
>>>Ah , didn't realise.
>>Only on the Eurostar, mind - the train is so long that any
>>oscillations on the overhead line induced by the passing of the first
>>pantograph are considered to have died down sufficiently in time for
>>the passing of the second pantograph.
>>
>
> A brief calculation suggests the elapsed time between the passage of
> the pantographs at full speed is not hugely different between the
> Eurostar and the Pendolino:
>
> E* 4.8sec
> Pendolino (9 car) 3.9 sec
> Pendolino (11 car) 4.8 sec
>
> Admittedly I've taken the train length as the distance between
> pantographs for simplicity
>
> Perhaps we might see the lengthened Pendolini running with both pans
> up?

Do you happen to have the time interval between the pans on a coupled
pair of 86s such as freightliner run? But then everyone goes on about
how robustly the WCML catenery was built. That said, as pendolini have
buses between the pans, I can see no benefit to running with both up,
and it would increase the wear on the pans by using each one twice as much.

When I once met someone at virgin trains, they told me that the
intention of the designers of the pendolino was that they should run
with the rear pan up, so that if it does something nasty with the
overhead, there is a chance that the front pan will be clear, and the
train can switch to that. He then told me that the trains are generally
run with the front pan up, but didn't say why. Anyone have an
explanation for it?

Robin

[Sam Wilson]

In article
<ece3c4ff-c652-4173-b177-421b00c03d38@b1g2000hsg.************.com>,
Boltar <boltar2003**********.uk> wrote:

> On Sep 24, 11:22 am, Mizter T <mizte...@**********> wrote:
> > because of safety concerns in the chunnel there is no high voltage bus
> > [ along the roof of a Eurostar ]
>
> The HSE bed wetters strike again. Though perhaps if that had allowed a
> high voltage line along the train but *hadn't* allowed trucks to be
> transported in the tunnel then we'd probably be a lot better off.

Leaving aside the technicality of whether it was the HSE or not, the
reason is that each half of a Eurostar is an independent entity and the
design aim[1] is that each half could operate independently in case of
emergency[2]. Disconnecting a 25 kV bus line would be difficult.

Sam

[1] Possibly now abandoned in the same way as the idea of driving a
burning freight Shuttle through the tunnel has been.

[2] And one half could pull or propel the other half through the tunnel
in case of failure.