OT: Rail crash

Tony Raven said:

My SO was up in Preston on Friday, coming back via Euston on Saturday
afternoon. Following the Virgin rail crash we were expecting much
disruption on the return journey so I started monitoring the trains
using Live Departures on the National Rail website. Apart from the
trains not running north of Lancaster, a full on-time service from
Preston to London was run throughout the day. The train my SO was on
left on time and arrived in London on time and apparently there were
fleets of buses at Preston station to ferry passengers over the closed
section.

We give the trains a lot of knocking but to run a service like that the
morning after a major crash and the closure of a big chunk of the route
I found pretty impressive. Almost as impressive as the way the
carriages survived the accident.

Getting back on topic...

Will they take bikes on the replacement bus service?

--
Phil Cook looking north over the park to the "Westminster Gasworks"

"Tony Raven" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

My SO was up in Preston on Friday, coming back via Euston on Saturday
afternoon. Following the Virgin rail crash we were expecting much
disruption on the return journey so I started monitoring the trains using
Live Departures on the National Rail website. Apart from the trains not
running north of Lancaster, a full on-time service from Preston to London
was run throughout the day. The train my SO was on left on time and
arrived in London on time and apparently there were fleets of buses at
Preston station to ferry passengers over the closed section.

We give the trains a lot of knocking but to run a service like that the
morning after a major crash and the closure of a big chunk of the route I
found pretty impressive. Almost as impressive as the way the carriages
survived the accident.

The report is, that the train driver steered the train to prevent some
unnecessary damage, can someone please tell me how they can steer a train
wich has left the track?

Alan

"Alan Holmes" <[email hidden]> wrote in
news:[email hidden]:

Quoted message said:

The report is, that the train driver steered the train to prevent some
unnecessary damage, can someone please tell me how they can steer a
train wich has left the track?

If you can operate the brakes differentially, you might be able to brake
one side only (brake steering) or apply the brakes at the rear of the train
only (to delay the onset of jack-knifing).

On 25 Feb 2007 17:08:56 GMT,

Will Cove said:

"Alan Holmes" <[email hidden]> wrote in
news:[email hidden]:

Quoted message said:

The report is, that the train driver steered the train to prevent some
unnecessary damage, can someone please tell me how they can steer a
train wich has left the track?

If you can operate the brakes differentially, you might be able to brake
one side only (brake steering) or apply the brakes at the rear of the train
only (to delay the onset of jack-knifing).

I read that he continued to operate the train. I'd assumed that meant
things like controlling the brakes rather than steering.

Tim

--
God said, "div D = rho, div B = 0, curl E = - @B/@t, curl H = J + @D/@t,"
and there was light.

http://tjw.hn.org/ http://www.locofungus.btinternet.co.uk/

"Tim Woodall" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

On 25 Feb 2007 17:08:56 GMT,

Will Cove said:

"Alan Holmes" <[email hidden]> wrote in
news:[email hidden]:

Quoted message said:

The report is, that the train driver steered the train to prevent some
unnecessary damage, can someone please tell me how they can steer a
train wich has left the track?

If you can operate the brakes differentially, you might be able to brake
one side only (brake steering) or apply the brakes at the rear of the
train
only (to delay the onset of jack-knifing).

I read that he continued to operate the train. I'd assumed that meant
things like controlling the brakes rather than steering.

Later reports stated that the train driver had no recollection of events so
how he can be credited with continuing to operate the train is beyond me.
There is no differential braking available to any train driver. The wheels
are very firmly fixed to the axles ruling out differential braking.
Similarly the ability to apply brakes to different parts of the train is not
an option. The brakes are a continuous system running the length of the
train.

There are several safety devices in the drivers cab including the 'dead
man's handle' i.e. there is a handle that must be kept continuously
depressed to maintain the supply of power to the traction motors. If the
driver takes his/her hand off the 'deadman's handle' the brakes are
automatically applied after a predetermined delay.

Having experienced the acrobatics of being thrown around in inside of a
coach during a crash ( a motor coach which didn't make it round a sharp bend
and was briefly airborn and then on two wheels), I think that there might
have been limited scope for the driver to do anything other than to hang on
for dear life.

On Sun, 25 Feb 2007 21:31:50 -0000 someone who may be "vernon"
<[email hidden]> wrote this:-

Quoted message said:

There are several safety devices in the drivers cab including the 'dead
man's handle' i.e. there is a handle that must be kept continuously
depressed to maintain the supply of power to the traction motors. If the
driver takes his/her hand off the 'deadman's handle' the brakes are
automatically applied after a predetermined delay.

It is normally a pedal and I assume it is so on these trains. This
has to be pressed to start the train and releasing it will stop the
train. Every minute a bleeping noise will sound in the cab and the
pedal must be released and depressed within a few seconds, otherwise
the train will stop. This is to guard against a driver being able to
keep the pedal pressed by reflex but not alert enough to operate the
controls. Operating some of the major controls will also reset the
timer on the bleeper, to reduce driver workload when they have shown
themselves to be alert.

Just one example of the safety systems built into railways which are
absent on the roads.

--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000/00023--e.htm#54

Alan Holmes said:

The report is, that the train driver steered the train to prevent some
unnecessary damage, can someone please tell me how they can steer a train
wich has left the track?

Countersteer

-dan

--
http://www.coruskate.net/

Daniel Barlow said:

Alan Holmes said:

The report is, that the train driver steered the train to prevent some
unnecessary damage, can someone please tell me how they can steer a train
wich has left the track?

Countersteer

:-)

Given the train in question is a pendolino I supose the driver could
have switched the tilt off and it might have had some effect. But I'm
with Vernon on this one. I reckon he was hanging on for dear life.
--
Phil Cook looking north over the park to the "Westminster Gasworks"

On Sun, 25 Feb 2007 16:55:21 GMT someone who may be "Alan Holmes"
<[email hidden]> wrote this:-

Quoted message said:

The report is, that the train driver steered the train to prevent some
unnecessary damage, can someone please tell me how they can steer a train
wich has left the track?

The various reports appear to be partly caused by journalists
interpreting remarks made by Mr Branson and partly caused by the
remarks themselves.

Excuses for the journalists include the time pressures they operate
under. Excuses for Mr Branson include is lack of knowledge of the
details of the things he is the figurehead for, having just returned
from holiday, lack of the usual spinners around him and, perhaps, a
reaction to what he had just seen.

Whatever the reasons for the reports, trains are not steered by the
driver, even if there is what appears to be a steering wheel in the
cab (not the case with these trains). Such "steering wheels" are
hand brakes for older UK trains and the power controller of trains
following French practice.

--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000/00023--e.htm#54

Alan Holmes said:

The report is, that the train driver steered the train to prevent some
unnecessary damage, can someone please tell me how they can steer a train
wich has left the track?

Well, it's easier than steering a train that's still constrained by the
track. I imagine the full crash report will say what happened when it's
released, but until now, there's nothing to do but wait until then to know.

A

Ambrose Nankivell wrote on 27/02/2007 16:47 +0100:

Quoted message said:

Alan Holmes said:

The report is, that the train driver steered the train to prevent some
unnecessary damage, can someone please tell me how they can steer a
train wich has left the track?

Well, it's easier than steering a train that's still constrained by the
track. I imagine the full crash report will say what happened when it's
released, but until now, there's nothing to do but wait until then to know.

I would imagine it's more likely to be control of the braking. I can't
imagine that running and leaving the automatic braking systems to try
and stop it would have had a better outcome than trying to reduce the
speed somewhat less rapidly and hope not to jack-knife the train in the
process. As it was it seems to have pretty much stopped in a straight
line apart from the roll down the embankment. I am not sure that
leaving it to do an automatic emergency stop would have done the same.

--
Tony

"...has many omissions and contains much that is apocryphal, or at least
wildly inaccurate..."
Douglas Adams; The Hitchhiker's Guide to the Galaxy

Tony Raven said:

Ambrose Nankivell wrote on 27/02/2007 16:47 +0100:

Quoted message said:

Alan Holmes said:

The report is, that the train driver steered the train to prevent
some unnecessary damage, can someone please tell me how they can
steer a train wich has left the track?

Well, it's easier than steering a train that's still constrained by
the track. I imagine the full crash report will say what happened when
it's released, but until now, there's nothing to do but wait until
then to know.

I would imagine it's more likely to be control of the braking. I can't
imagine that running and leaving the automatic braking systems to try
and stop it would have had a better outcome than trying to reduce the
speed somewhat less rapidly and hope not to jack-knife the train in the
process. As it was it seems to have pretty much stopped in a straight
line apart from the roll down the embankment. I am not sure that
leaving it to do an automatic emergency stop would have done the same.

I wonder how much you can control the brakeing of a derailed train, as
IMHO it would brake completely differently to when it is on the rails.

e.g. the sharp bits of the wheels would be bumping along the sleepers,
as opposed to the flat bits on the rails. Also it would be kicking up a
lot of gravel and such.

Martin.

Martin Dann wrote on 28/02/2007 00:57 +0100:

Quoted message said:

I wonder how much you can control the brakeing of a derailed train, as
IMHO it would brake completely differently to when it is on the rails.

e.g. the sharp bits of the wheels would be bumping along the sleepers,
as opposed to the flat bits on the rails. Also it would be kicking up a
lot of gravel and such.

Presumably a situation where an automatic emergency brake would just
lock the wheels, which, as we know, is not the best way to control a
stop. Someone at the controls can try to brake more gently to prevent
that. I'm just speculating though and only one person knows.

--
Tony

"...has many omissions and contains much that is apocryphal, or at least
wildly inaccurate..."
Douglas Adams; The Hitchhiker's Guide to the Galaxy

On Wed, 28 Feb 2007 00:17:33 +0000 someone who may be Tony Raven
<[email hidden]> wrote this:-

Quoted message said:

I would imagine it's more likely to be control of the braking.

I have no doubt at all that the driver applied maximum braking, it
is the best course of action in any circumstances other than a
derailed vehicle in the middle of a train not fitted with continuous
brakes (such trains have not run for decades). The driver may
release the braking at low speed to stop the train in a suitable
place (for example stopping on a bridge is not a good idea if it can
be avoided).

Anyway, as soon as the first coach parted from the others maximum
braking would have been applied automatically, throughout both parts
of the train.

Quoted message said:

I can't
imagine that running and leaving the automatic braking systems to try
and stop it would have had a better outcome than trying to reduce the
speed somewhat less rapidly and hope not to jack-knife the train in the
process.

You appear to be thinking of lorries, which behave somewhat
differently.

Anyway, once derailed the forces exerted on a train by the brakes
are minor compared to the forces exerted by the wheels running over
sleepers and ballast. The reason that the train broke in two at
Hatfield was that the forces exerted by the ballast were far greater
ten the couplings could cope with, despite there being maximum
braking on all wheels at the time.

--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000/00023--e.htm#54

David Hansen wrote on 28/02/2007 09:40 +0100:

Quoted message said:

Anyway, once derailed the forces exerted on a train by the brakes
are minor compared to the forces exerted by the wheels running over
sleepers and ballast. The reason that the train broke in two at
Hatfield was that the forces exerted by the ballast were far greater
ten the couplings could cope with, despite there being maximum
braking on all wheels at the time.

You get such a good education on urc.

--
Tony

"...has many omissions and contains much that is apocryphal, or at least
wildly inaccurate..."
Douglas Adams; The Hitchhiker's Guide to the Galaxy

"Tony Raven" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

Presumably a situation where an automatic emergency brake would just lock
the wheels, which, as we know, is not the best way to control a stop.
Someone at the controls can try to brake more gently to prevent that. I'm
just speculating though and only one person knows.

Someone on uk.railway enlightened me and many others by pointing out that
the pendolino train involved in the accident has a device to apply sand to
the rails if the wheels lock during an emergency stop and try and create
more friction.
I think in the autumn when there's leaves everywhere, train drivers do brake
a bit more gently than usual to make sure the train doesn't slide.

If the train wheels aren't on the track however, I doubt there's very much
the driver can do.

--
peter

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