Dangers of High Speed Trains Pushed from the Rear
 

1/ the rear power car, still under full power, caused much of the
crumpling and jack knifing, and

This is believed to be incorrect, but is in the interim HSE report
which might explain why it got posted here.

The unfounded idea that the rear power car was still under full power
was certainly NOT in the interim HSE report. It was an ignorant rumour
that I believe was mentioned first on Sky News a few hours after the
crash.
--

I can see where this has come about. There is a BBC website report that
states "The front of the First Great Western train ploughed into the
embankment, while the rear power car on the train continued to propel the
train forward, investigators found."

What they have missed out is "momentum of", which is in the HSE report.

...and the investigators might have pointed out that the momentum of the
rear eight coaches acting on the (derailed) leading power car was a lot
greater than the momentum of the rear power car.

David

I'm going to wander off topic here slightly... but i hope it's still
relevant.

Wasn't the Lockington accident made worse by the fact that a heavier
DMU set was at the rear?

If i recall correctly wasn't it a 105/114 pairing? Making it even
worse the 105 trailer car was leading (thus the lightest carriage of
the four), and class 105s being of shorter body length and pretty
appalling crashworthiness wise, would have made things worse. Shorter
bodylength being worse cos damage from front and behind on the first
carriage would be more catastrophic.

The 105 trailer struck the van on the level crossing and then the
heavier carriages behind kept it going and lots of track was damaged
leading to serious damage to all four vehicles.

So maybe there is a point about the heavier vehicles behind keeping
the train moving.

Slamdoor Mat.

Dangers of High Speed Trains Pushed from the Rear
 

On Thu, 11 Nov 2004 13:31:57 GMT someone who may be James Robinson
wrote this:-

- There is no mention of the power setting in the interim report.

Irrelevant. We know that with the brakes applied traction power
cannot be obtained.

It is possible that the control system was deranged during the
initial impact. However in that case the rear data recorder and the
front data recorder would disagree. I imagine this would be
mentioned by the RI.



--
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Dangers of High Speed Trains Pushed from the Rear
 

"Clive Coleman" wrote in message
...
In message , dwb
writes
econdly, the rear power car was NOT under the full power.
The train's 'black box recorder' that the power notch was at zero and
the brake handle was in 'emergency'. It was simply the inertia of the
rear power car (which had already derailed) that kept it moving.
Do you KNOW that?

Yes. To quote Network Rail's report:

"1C92 struck the car at 18:05/32. OTMR indicates that 1C92's brakes were
applied two to three seconds before the collision. Leading wheelset of 1C92
derailed on the crossing on impact with the stationary car."

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*** http://www.railwayscene.co.uk/ ***
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MSN: richmackin-at-hotmail-dot-com

Dangers of High Speed Trains Pushed from the Rear
 

Irrelevant. We know that with the brakes applied traction power
cannot be obtained.

Does this mean that any brake application automatically cuts traction power?

It's typical in North America to "power brake". In power braking, the
throttle is left in notch two or three, the independent brake in full
release while the train is brought to a stand with the train brake working
against the throttle. Is this not possible in the UK?


--
Cheers
Roger T.

Home of the Great Eastern Railway
http://www.highspeedplus.com/~rogertra/

Dangers of High Speed Trains Pushed from the Rear
 

On Thu, 11 Nov 2004 12:04:55 -0800, Roger T. wrote:



Irrelevant. We know that with the brakes applied traction power
cannot be obtained.

Does this mean that any brake application automatically cuts traction power?

It's typical in North America to "power brake". In power braking, the
throttle is left in notch two or three, the independent brake in full
release while the train is brought to a stand with the train brake working
against the throttle. Is this not possible in the UK?

You are also comparing a technique to handle slack in a long rake of
goods wagons with the operation of relatively short rake of passenger
rolling stock with low slack couplers and a locomotive on each end, not
just the front.

I would be surprised if goods trains in the UK didn't also use the 'power
brake' technique to stop the slack from running in.

Dangers of High Speed Trains Pushed from the Rear
 

On Thu, 11 Nov 2004 12:04:55 -0800 someone who may be "Roger T."
wrote this:-

Does this mean that any brake application automatically cuts traction power?

That is my understanding and it has been stated by others who are in
a position to know. Such an interlock appears to have been common
since the 1960s.


--
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I will always explain revoked keys, unless the UK government
prevents me by using the RIP Act 2000.


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Dangers of High Speed Trains Pushed from the Rear
 

"Roger T." wrote
It's typical in North America to "power brake". In power
braking, the
throttle is left in notch two or three, the independent brake
in full
release while the train is brought to a stand with the train
brake working
against the throttle. Is this not possible in the UK?

Not with the stuff I drive. Why would you do that?
Nev

Dangers of High Speed Trains Pushed from the Rear
 

"Matthew Geier"

Irrelevant. We know that with the brakes applied traction power
cannot be obtained.

Does this mean that any brake application automatically cuts traction
power?

It's typical in North America to "power brake". In power braking, the
throttle is left in notch two or three, the independent brake in full
release while the train is brought to a stand with the train brake
working
against the throttle. Is this not possible in the UK?

You are also comparing a technique to handle slack in a long rake of
goods wagons with the operation of relatively short rake of passenger
rolling stock with low slack couplers and a locomotive on each end, not
just the front.

I would be surprised if goods trains in the UK didn't also use the 'power
brake' technique to stop the slack from running in.

Nope, "power braking: is common, even on passenger trains. Even North
America steam used the "power brake" technique.


--
Cheers
Roger T.

Home of the Great Eastern Railway
http://www.highspeedplus.com/~rogertra/

Dangers of High Speed Trains Pushed from the Rear
 

"Nev Arthur"

"Roger T." wrote
It's typical in North America to "power brake". In power braking, the
throttle is left in notch two or three, the independent brake in full
release while the train is brought to a stand with the train brake
working
against the throttle. Is this not possible in the UK?

Not with the stuff I drive. Why would you do that?
Nev

To Keep the slack stretched. Remember, even North American passenger trains
have slack. An inch or so in every coupling between each car.


--
Cheers
Roger T.

Home of the Great Eastern Railway
http://www.highspeedplus.com/~rogertra/

Dangers of High Speed Trains Pushed from the Rear
 

David Hansen wrote:

James Robinson wrote this:

- There is no mention of the power setting in the interim report.

Irrelevant. We know that with the brakes applied traction power
cannot be obtained.

Yes, I'll grant you that.

Yes, it's likely that an emergency application was made, but my point
was that the RI report was not detailed enough to make that clear, and
people are jumping to conclusions.

Beyond that, the other three points I made still stand.