brake valve fails, train runs away
Paul Hirose
brake valve handle suddenly has no effect. Engineer applies
independent brakes, but they can't stop the train due to its weight on
a descending grade. Crew jumps. Train continues onto branch line,
smashes through a tunnel which is too low for the locomotive, and
finally collides with a light locomotive which just left the quarry.
Nobody is injured, but two locomotives and several cars are damaged in
the collision and derailment.
It all began when a roll pin fractured inside the brake valve. Its
handle became useless. Releasing the deadman pedal was no help because
the brake system was designed to ignore it if the locomotive brake
cylinders had at least 30 PSI. There was no other means in the cab to
exhaust the train line.
This actually happened in the UK, but the locomotive was American
made, "the only one of this type, and with this type of brake
controller, operating in the UK."
http://www.raib.gov.uk/publications/bulletins/bulletins_2009/bulletin_03_2009.cfm
--
Paul Hirose <jvcmz...@earINVALIDthlink.net>
To reply by email remove INVALID
Mark Cahill
cab. If so equipped, the engineer could have tried that to get the train
brakes on.
If not equipped as you say, then release the independent brake and hope the
deadman pedal system dumps the train.
Mark
Also,
"Paul Hirose" <jvcmz...@earINVALIDthlink.net> wrote in message
news:spidnez9uOi_xwnU...@earthlink.com...
John Albert
"It all began when a roll pin fractured inside the brake
valve. Its
handle became useless. Releasing the deadman pedal was no
help because
the brake system was designed to ignore it if the locomotive
brake
cylinders had at least 30 PSI. There was no other means in
the cab to
exhaust the train line."
Amazin'!
No emergency brake valve on the "fireman's side" in the cab?
No regulating valve for the #26 brake? (just turn the
regulating valve down, down down, I've seen old-time
engineers who didn't trust "pressure maintaining" operate in
EXACTLY this manner).
As a last ditch effort, I would have put on the independent
brake, told the conductor to pull the pin, and then opened
up the engine and pulled the train apart. BUT WAIT! Ain't
European-style couplings great?
And - as Mark Cahill mentioned - bail OFF the indendent
brake and let the deadman feature kick in....
- John
Stephen Furley
On 12/2/09 19:20, in article OD_kl.12274$W06....@flpi148.ffdc.sbc.com,
"John Albert" <j.al...@snet.net> wrote:
> RE:
> "It all began when a roll pin fractured inside the brake
> valve. Its
> handle became useless. Releasing the deadman pedal was no
> help because
> the brake system was designed to ignore it if the locomotive
> brake
> cylinders had at least 30 PSI. There was no other means in
> the cab to
> exhaust the train line."
>
> Amazin'!
>
> No emergency brake valve on the "fireman's side" in the cab?
This has been discussed at some length elsewhere.
No, rather surprisingly, no emergency brake valve was fitted. It's rather
difficult to understand why, surely not cost, which would have been minimal
for a few metres of pipe, a cock, a 'T' piece to cut into the train pipe, a
few other pipe fittings, and maybe one or two man hours of work to fit it
during original construction. Such a valve is to be fitted to the
locomotive during repairs, and has already been fitted to another locomotive
with similar equipment.
>
> No regulating valve for the #26 brake? (just turn the
> regulating valve down, down down, I've seen old-time
> engineers who didn't trust "pressure maintaining" operate in
> EXACTLY this manner).
I don't understand this; what's a '#26 brake'? By 'regulating valve' do you
mean a valve which can be adjusted by the driver to vary the pressure to
which the train pipe is charged when the brakes are released? If so, then I
don't think that such a valve is normally fitted in this country; obviously,
something's got to set that pressure, but I don't think it's adjustable by
the driver.
> As a last ditch effort, I would have put on the independent
> brake, told the conductor to pull the pin, and then opened
> up the engine and pulled the train apart. BUT WAIT! Ain't
> European-style couplings great?
I doubt that the train would have had a 'conductor', or guard, but even if
American-style automatic couplers were fitted, which some stone wagons in
this country do have, there would be no way to uncouple them from the train;
it would have to be done from the ground, and therefore couldn't be done
while the train was moving.
> And - as Mark Cahill mentioned - bail OFF the indendent
> brake and let the deadman feature kick in....
That would probably have been the best thing to do under the circumstances
it seems that crews were not well trained in the operation of the deadman's
device, and may not have understood that it was necessary to release the
straight air brake before it would work. When you're running downhill, with
a heavy stone train behind you and the train brakes have failed, it's not
exactly obvious that the best thing to do is to release the only functioning
brake that you do have, even if that's not managing to stop the train.
Seems to have been a combination of poor design of equipment, and inadequate
training of crew.
The official report into the accident is here:
Chris D
"John Albert" <j.al...@snet.net> wrote in message
news:OD_kl.12274$W06....@flpi148.ffdc.sbc.com...
I'm surprised that there's no emergency brake cock within the locomotives
cab. Any failure of the brake equipment can them be bypassed by opening the
BP emergency cock. Most Australian loci's have this option. It's a must have
on all new loco's for the last 30 years.
Chris
Roger T.
> cab. Any failure of the brake equipment can them be bypassed by opening
> the BP emergency cock. Most Australian loci's have this option. It's a
> must have on all new loco's for the last 30 years.
Practically every Canadian steam loco had an angle cock right over the
engineer's gangway/cab entrance that he could open just before bailing out.
--
Cheers.
Roger T.
See the GER at: -
http://www.islandnet.com/~rogertra/
John McCoy
news:X4_kl.464$g31...@nwrddc01.gnilink.net:
> Most contemporary locomotives have emergency "dump" valves located in
> the cab. If so equipped, the engineer could have tried that to get the
> train brakes on.
For values of "contemporary" that extend back to at least 1913
(the 1913 ALCO I used to run had two such valves, one behind
the engineer and one on the fireman's side).
I doubt any American engine built in the last century did not
have such valves.
Most likely the contractor using the engine (or a previous owner)
removed the valves for some reason. It wouldn't be the first
example of a quarry or industrial engine with poor maintenance
and weird modifications.
John
John McCoy
news:C5BA32E0.227DD%aoo...@dsl.pipex.com:
> I don't understand this; what's a '#26 brake'?
Model of air brake system. The current system is the "26L". There
are various older systems, most prominently the "6 brake", which
refers to the 6ET and it's derivatives. If the engine in question
is of fairly new construction it probably has a 26 brake; if it's
more than maybe 30 years old it likely has a 6 brake.
John
Chris D
"Roger T." <roge...@highspeedplus.com> wrote in message
news:afd4a3bd7b4afe0d...@grapevine.islandnet.com...
>> I'm surprised that there's no emergency brake cock within the locomotives
>> cab. Any failure of the brake equipment can them be bypassed by opening
>> the BP emergency cock. Most Australian loci's have this option. It's a
>> must have on all new loco's for the last 30 years.
>
> Practically every Canadian steam loco had an angle cock right over the
> engineer's gangway/cab entrance that he could open just before bailing
> out.
Do you bail out or ride it out. That is the question??? And you probably
wont have not much time to think it over either. Certainly, the current
diesel cab standards are good and your don't have to worry about being
cooked by a bust boiler.
Regards....Chris
Paul Hirose
> told the conductor to pull the pin, and then opened up the engine
> and pulled the train apart. BUT WAIT! Ain't European-style couplings
> great?
In "The Train", actor Albert Rémy uncouples a French
locomotive on the fly. He loosens the screw, then lifts the
hook free when Burt Lancaster hits the brakes to compress the buffers.
This was a real train in motion. John Frankenheimer (director) said an
actor doing a stunt like that would probably be out of the question
nowadays. One slip and the guy could have been maimed or killed.
Getting back to the UK runaway, maybe someone could have stepped out
of the cab and opened the angle cock at the front of the locomotive.
It appears to have been running cab-forward. From the photo in the
accident report I can't tell if the cock is within reach, though.
But there is a good picture of the brake valve. As others noted,
it appears the locomotive had #26 air brakes. That would be
consistent with the equipment "being of a design that was in
widespread use in North America."
The report says, "The system also included a feature that disabled the
deadman pedal whenever a minimum pressure of 30lb/sq in (2.08 bar) was
detected in the locomotive brake cylinders (this is a feature fitted
to some shunting locomotives that enables the driver to leave his seat
to observe the passage of the train, or to move to the control
position on the other side of the cab)."
On the other hand, my manual on 26-L air brakes (New York Air Brake
Co., 1964) does not imply this was an optional feature. The 30 PSI
override is described as a normal part of the system.
It's accomplished by the pneumatic equivalent of an electronic "NOR
gate". Air to disable the pedal comes from the brake valve when the
handle is in the Suppression position. It's also tapped off the pipe
to the locomotive brake cylinders. Both sources meet at a double check
valve, arranged so sufficient pressure in either pipe will drive a
spring loaded piston to shut off the pipe to the deadman pedal.
The book's schematics also show a normal installation included one or
two emergency valves connected to the brake pipe as a backup method to
apply the train brakes.