Train wreck . . .
 

www.tornado1.wmv

Amazing video! Only a RR person would appreciate this; but the final scene was of the broken-off
rear part of the train which continued down the track to collide with the front half. Normally,
when a train breaks in two like that one, automatic air brakes are applied to both portions.
Theoretically, both halves should come to full "emergency stop" to prevent a reconnect disaster like
that one.

Bob Swinney

Train wreck . . .
 

William Wixon wrote:
(top posting fixed)

"Robert Swinney" wrote in message
...
www.tornado1.wmv

Amazing video! Only a RR person would appreciate this; but the final
scene was of the broken-off
rear part of the train which continued down the track to collide with the
front half. Normally,
when a train breaks in two like that one, automatic air brakes are applied
to both portions.
Theoretically, both halves should come to full "emergency stop" to prevent
a reconnect disaster like
that one.

Bob Swinney



that's horrifying. awesome (in the original definition).

http://www.youtube.com/watch?v=cFe0846RgWc

(my second father was a locomotive engineer.)

b.w.


Also awful (in the original definition). I assume it's the same one I
saw a month or so ago -- I cringed enough when I saw it, don't need to
see it again!!

A search on 'Westinghouse Brakes' should cough up some interesting
tidbits. The pneumatic brake technology used in trains is over 100
years old. It's functional, but it has some severe drawbacks. There
are way better ways* to stop a train now, but inter-railway politics,
inertia and what not** have kept them from being adopted.

* Brake by wire! Just like Toyota***!

** Union-railway politics...

*** Oh, wait...

--
Tim Wescott
Control system and signal processing consulting
www.wescottdesign.com

Train wreck . . .
 

William Wixon wrote:
that's horrifying. awesome (in the original definition).

http://www.youtube.com/watch?v=cFe0846RgWc

(my second father was a locomotive engineer.)

b.w.


This one has edited down to the interesting part:
http://www.youtube.com/watch?v=LYubpuIe3cw&NR=1

Bob

Train wreck . . .
 

that's horrifying. awesome (in the original definition).

http://www.youtube.com/watch?v=cFe0846RgWc

(my second father was a locomotive engineer.)

b.w.


"Robert Swinney" wrote in message
...
www.tornado1.wmv

Amazing video! Only a RR person would appreciate this; but the final
scene was of the broken-off
rear part of the train which continued down the track to collide with the
front half. Normally,
when a train breaks in two like that one, automatic air brakes are applied
to both portions.
Theoretically, both halves should come to full "emergency stop" to prevent
a reconnect disaster like
that one.

Bob Swinney

Train wreck . . .
 

"Robert Swinney" wrote in message
...
www.tornado1.wmv

Amazing video! Only a RR person would appreciate this; but the final
scene was of the broken-off
rear part of the train which continued down the track to collide with the
front half. Normally,
when a train breaks in two like that one, automatic air brakes are applied
to both portions.
Theoretically, both halves should come to full "emergency stop" to prevent
a reconnect disaster like
that one.

Bob Swinney

I can see the sparks from something on the rearward section's leading car.
May be braking of the front car. But, like you, I thought that when the air
was disconnected, that everything automatically braked. If the rearward
section's cars all braked individually, I don't think it would have been
pushing that front tank car like it was. I was expecting an explosion when
the tanker hit. Some pretty incredible footage, nonetheless. Just like
everything else, there can be malfunctions, or **** poor mechanics.

Steve

Train wreck . . .
 

"Robert Swinney" wrote in message
...
www.tornado1.wmv

Amazing video! Only a RR person would appreciate this; but the final
scene was of the broken-off
rear part of the train which continued down the track to collide with the
front half. Normally,
when a train breaks in two like that one, automatic air brakes are applied
to both portions.
Theoretically, both halves should come to full "emergency stop" to prevent
a reconnect disaster like
that one.

Bob Swinney

I am not a railroad person, and I appreciated it. What can it mean?

Steve ;-)

Train wreck . . .
 

"Robert Swinney" wrote in message
...
www.tornado1.wmv

Amazing video! Only a RR person would appreciate this; but the final
scene was of the broken-off
rear part of the train which continued down the track to collide with the
front half. Normally,
when a train breaks in two like that one, automatic air brakes are applied
to both portions.
Theoretically, both halves should come to full "emergency stop" to prevent
a reconnect disaster like
that one.

Bob Swinney


My bet the brakes applied just fine, but the veiw is rearward from the
locomotive, (or set of locos), which stopped right away as it just had it's
own momentum to stop, where the rest of the train had perhaps a mile of cars
to stop, and that is not going to stop quickly!

Train wreck . . .
 

Looked like the leading truck on the tanker had rotated
on the track so the wheels were not true - making the
brakes in that truck non-functional.

The train might have been in the push-pull mode - a push
train driving the cars towards the lead engine.

The electrical cables to that car would have been lost -
one would assume it would stop - but perhaps it decoupled
as well...

Would be nice to read the final report.

Martin

Steve B wrote:
"Robert Swinney" wrote in message
...
www.tornado1.wmv

Amazing video! Only a RR person would appreciate this; but the final
scene was of the broken-off
rear part of the train which continued down the track to collide with the
front half. Normally,
when a train breaks in two like that one, automatic air brakes are applied
to both portions.
Theoretically, both halves should come to full "emergency stop" to prevent
a reconnect disaster like
that one.

Bob Swinney

I can see the sparks from something on the rearward section's leading car.
May be braking of the front car. But, like you, I thought that when the air
was disconnected, that everything automatically braked. If the rearward
section's cars all braked individually, I don't think it would have been
pushing that front tank car like it was. I was expecting an explosion when
the tanker hit. Some pretty incredible footage, nonetheless. Just like
everything else, there can be malfunctions, or **** poor mechanics.

Steve

Train wreck . . .
 

"Greg O" wrote in message
...

"Robert Swinney" wrote in message
...
www.tornado1.wmv

Amazing video! Only a RR person would appreciate this; but the final
scene was of the broken-off
rear part of the train which continued down the track to collide with the
front half. Normally,
when a train breaks in two like that one, automatic air brakes are
applied to both portions.
Theoretically, both halves should come to full "emergency stop" to
prevent a reconnect disaster like
that one.

Bob Swinney


My bet the brakes applied just fine, but the veiw is rearward from the
locomotive, (or set of locos), which stopped right away as it just had
it's own momentum to stop, where the rest of the train had perhaps a mile
of cars to stop, and that is not going to stop quickly!

Don't forget the locomotive has dynamic braking, which is some sort of
electric talk for reducing the power to the motors, which slows them down
electrically, and not with friction.

Steve

Train wreck . . .
 

On 2010-03-13, Steve B wrote:

"Greg O" wrote in message
...

"Robert Swinney" wrote in message
...
www.tornado1.wmv

Amazing video! Only a RR person would appreciate this; but the final
scene was of the broken-off
rear part of the train which continued down the track to collide with the
front half. Normally,
when a train breaks in two like that one, automatic air brakes are
applied to both portions.
Theoretically, both halves should come to full "emergency stop" to
prevent a reconnect disaster like
that one.

Bob Swinney


My bet the brakes applied just fine, but the veiw is rearward from the
locomotive, (or set of locos), which stopped right away as it just had
it's own momentum to stop, where the rest of the train had perhaps a mile
of cars to stop, and that is not going to stop quickly!

Don't forget the locomotive has dynamic braking, which is some sort of
electric talk for reducing the power to the motors, which slows them down
electrically, and not with friction.

Electric braking uses motors as generators, and dumps the energy into
big resistors.

Regenerative braking is only available on electrified railroads. It
also uses the motors as generators, but instead of just dumping elergy
into resistors, it returns them into the railroad's power system via
overhead cable.

i

Train wreck . . .
 

On Mar 13, 8:26*am, "Steve B" wrote:
"Greg O" wrote in message

...





"Robert Swinney" wrote in message
m...
www.tornado1.wmv

Amazing video! *Only a RR person would appreciate this; *but the final
scene was of the broken-off
rear part of the train which continued down the track to collide with the
front half. *Normally,
when a train breaks in two like that one, automatic air brakes are
applied to both portions.
Theoretically, both halves should come to full "emergency stop" to
prevent a reconnect disaster like
that one.

Bob Swinney

My bet the brakes applied just fine, but the veiw is rearward from the
locomotive, (or set of locos), which stopped right away as it just had
it's own momentum to stop, where the rest of the train had perhaps a mile
of cars to stop, and that is not going to stop quickly!

Don't forget the locomotive has dynamic braking, which is some sort of
electric talk for reducing the power to the motors, which slows them down
electrically, and not with friction.

Steve

Brakes on trains operate just like air brakes on trucks. The air holds
the brakes off. Lowering the air pressure begins to apply the brakes.
Each car has it's own compressed air tank holding perhaps 20-30
gallons of air. The air piping on a rr car is about 3/4 inch, as I
recall from many years ago. We lived near a RR track and I walked to
school past a cannery with many cars on the siding. I loved to watch
the old steam engine in operation, shuffeling the cars.

That is an awful lot of air to be released from a single coupling
hose, which is a 2 inch hose. Takes a long time to release the air,
which is why it takes a long time to stop a moving train. All the
stored air has to come out the engine end of the train.

Train watchers will remember occasions where the engineer gets in a
hurry to start a train and begins to pull before the air pressure has
reached the last car. You will hear a moving "BANG" go the entire
length of the train as the couplings are stretched from one car to the
next. If the brakes are all released before pulling, you won't hear a
thing, just see the movement transfer from car to car.

The opposite operation has to take place before a train can stop. The
brake air is bled off as the engine speed is reduced. This has the
effect of closing all the coupling slack on all the train cars. Once
this is done, the engineer can really begin to stop the engine with
it's brakes. and the trains braking will continue to increase,
beginning with the car right behind the engine.

Those train watchers who see the trains in Europe will remember the
couplings are totally different from the US. There they are held
together by a screw-together central coupling and have two spring
loaded bumpers to keep the screw coupling fairly tight. They don't
have the long start an stop time that the US and all trains in the
Americas have.

Hope this helps explain the video a little bit.

Paul

Train wreck . . .
 

A form of regen braking is available on some "diesel" locos. It consists of a huge bank of
resistors absorbing generated current from the DC traction motors. The resistors are housed in a
pod somewhere on the loco, usu. behind the cab near the top.

Bob Swinney
"Ignoramus4212" wrote in message
...
On 2010-03-13, Steve B wrote:

"Greg O" wrote in message
...

"Robert Swinney" wrote in message
...
www.tornado1.wmv

Amazing video! Only a RR person would appreciate this; but the final
scene was of the broken-off
rear part of the train which continued down the track to collide with the
front half. Normally,
when a train breaks in two like that one, automatic air brakes are
applied to both portions.
Theoretically, both halves should come to full "emergency stop" to
prevent a reconnect disaster like
that one.

Bob Swinney


My bet the brakes applied just fine, but the veiw is rearward from the
locomotive, (or set of locos), which stopped right away as it just had
it's own momentum to stop, where the rest of the train had perhaps a mile
of cars to stop, and that is not going to stop quickly!

Don't forget the locomotive has dynamic braking, which is some sort of
electric talk for reducing the power to the motors, which slows them down
electrically, and not with friction.

Electric braking uses motors as generators, and dumps the energy into
big resistors.

Regenerative braking is only available on electrified railroads. It
also uses the motors as generators, but instead of just dumping elergy
into resistors, it returns them into the railroad's power system via
overhead cable.

i

Train wreck . . .
 

On 2010-03-13, Robert Swinney wrote:
A form of regen braking is available on some "diesel" locos. It consists of a huge bank of
resistors absorbing generated current from the DC traction motors. The resistors are housed in a
pod somewhere on the loco, usu. behind the cab near the top.

What you are describing is not regenerative braking.

i

Bob Swinney
"Ignoramus4212" wrote in message
...
On 2010-03-13, Steve B wrote:

"Greg O" wrote in message
...

"Robert Swinney" wrote in message
...
www.tornado1.wmv

Amazing video! Only a RR person would appreciate this; but the final
scene was of the broken-off
rear part of the train which continued down the track to collide with the
front half. Normally,
when a train breaks in two like that one, automatic air brakes are
applied to both portions.
Theoretically, both halves should come to full "emergency stop" to
prevent a reconnect disaster like
that one.

Bob Swinney


My bet the brakes applied just fine, but the veiw is rearward from the
locomotive, (or set of locos), which stopped right away as it just had
it's own momentum to stop, where the rest of the train had perhaps a mile
of cars to stop, and that is not going to stop quickly!

Don't forget the locomotive has dynamic braking, which is some sort of
electric talk for reducing the power to the motors, which slows them down
electrically, and not with friction.

Electric braking uses motors as generators, and dumps the energy into
big resistors.

Regenerative braking is only available on electrified railroads. It
also uses the motors as generators, but instead of just dumping elergy
into resistors, it returns them into the railroad's power system via
overhead cable.

i

Train wreck . . .
 

Some good stuff, Paul, but no cigar.

RR air brakes are applied by sensing (brake control) valves in each car. As the engineer calls for
breaking he makes a "brake pipe reduction" in train line air of a graduated amount of psi. The
reduction within the entre brake line is felt simultaneously in each car causing the brake control
valves to move an equivalent amount.
In turn the brake valves release a corresponding amount of air from double ended reservoirs which go
to brake cylinders. To effect more braking, more train line pressure is reduced. Loco engineers
speak of this as so many pounds of braking. One of the down sides of this (Westinghouse AB system)
is that in order to release brakes, the train line pressure must be restored via main air reservoir
in the loco.

Slack action in long trains, particularly exacerbated by hilly terrain is a frequent cause of
drawbars and coupler breakage. Depending on train length and other conditions, going to "Big Hole"
full emergency stop can be a dangerous thing. Literally, the brakes have to be "pumped off" before
a train can be moved.

Bob Swinney






inet.com" wrote in message
...
On Mar 13, 8:26 am, "Steve B" wrote:
"Greg O" wrote in message

...





"Robert Swinney" wrote in message
m...
www.tornado1.wmv

Amazing video! Only a RR person would appreciate this; but the final
scene was of the broken-off
rear part of the train which continued down the track to collide with the
front half. Normally,
when a train breaks in two like that one, automatic air brakes are
applied to both portions.
Theoretically, both halves should come to full "emergency stop" to
prevent a reconnect disaster like
that one.

Bob Swinney

My bet the brakes applied just fine, but the veiw is rearward from the
locomotive, (or set of locos), which stopped right away as it just had
it's own momentum to stop, where the rest of the train had perhaps a mile
of cars to stop, and that is not going to stop quickly!

Don't forget the locomotive has dynamic braking, which is some sort of
electric talk for reducing the power to the motors, which slows them down
electrically, and not with friction.

Steve

Brakes on trains operate just like air brakes on trucks. The air holds
the brakes off. Lowering the air pressure begins to apply the brakes.
Each car has it's own compressed air tank holding perhaps 20-30
gallons of air. The air piping on a rr car is about 3/4 inch, as I
recall from many years ago. We lived near a RR track and I walked to
school past a cannery with many cars on the siding. I loved to watch
the old steam engine in operation, shuffeling the cars.

That is an awful lot of air to be released from a single coupling
hose, which is a 2 inch hose. Takes a long time to release the air,
which is why it takes a long time to stop a moving train. All the
stored air has to come out the engine end of the train.

Train watchers will remember occasions where the engineer gets in a
hurry to start a train and begins to pull before the air pressure has
reached the last car. You will hear a moving "BANG" go the entire
length of the train as the couplings are stretched from one car to the
next. If the brakes are all released before pulling, you won't hear a
thing, just see the movement transfer from car to car.

The opposite operation has to take place before a train can stop. The
brake air is bled off as the engine speed is reduced. This has the
effect of closing all the coupling slack on all the train cars. Once
this is done, the engineer can really begin to stop the engine with
it's brakes. and the trains braking will continue to increase,
beginning with the car right behind the engine.

Those train watchers who see the trains in Europe will remember the
couplings are totally different from the US. There they are held
together by a screw-together central coupling and have two spring
loaded bumpers to keep the screw coupling fairly tight. They don't
have the long start an stop time that the US and all trains in the
Americas have.

Hope this helps explain the video a little bit.

Paul

Train wreck . . .
 

Iggy,

What part of regenerative do you not understand?

Bob Swinney
"Ignoramus4212" wrote in message
...
On 2010-03-13, Robert Swinney wrote:
A form of regen braking is available on some "diesel" locos. It consists of a huge bank of
resistors absorbing generated current from the DC traction motors. The resistors are housed in a
pod somewhere on the loco, usu. behind the cab near the top.

What you are describing is not regenerative braking.

i

Bob Swinney
"Ignoramus4212" wrote in message
...
On 2010-03-13, Steve B wrote:

"Greg O" wrote in message
...

"Robert Swinney" wrote in message
...
www.tornado1.wmv

Amazing video! Only a RR person would appreciate this; but the final
scene was of the broken-off
rear part of the train which continued down the track to collide with the
front half. Normally,
when a train breaks in two like that one, automatic air brakes are
applied to both portions.
Theoretically, both halves should come to full "emergency stop" to
prevent a reconnect disaster like
that one.

Bob Swinney


My bet the brakes applied just fine, but the veiw is rearward from the
locomotive, (or set of locos), which stopped right away as it just had
it's own momentum to stop, where the rest of the train had perhaps a mile
of cars to stop, and that is not going to stop quickly!

Don't forget the locomotive has dynamic braking, which is some sort of
electric talk for reducing the power to the motors, which slows them down
electrically, and not with friction.

Electric braking uses motors as generators, and dumps the energy into
big resistors.

Regenerative braking is only available on electrified railroads. It
also uses the motors as generators, but instead of just dumping elergy
into resistors, it returns them into the railroad's power system via
overhead cable.

i

Train wreck . . .
 

On 2010-03-13, Robert Swinney wrote:
Iggy,

What part of regenerative do you not understand?

Read this:

http://en.wikipedia.org/wiki/Regenerative_braking

A regenerative brake is an energy recovery mechanism that reduces
vehicle speed by converting some of its kinetic energy and/or
potential energy (due to elevation) into a useful form of energy
instead of dissipating it as heat as in a conventional brake. The
converted kinetic energy is stored for future use or fed back into a
power system for use by other vehicles.

Electrical regenerative brakes in electric railway feed the generated
electricity back into the supply system. In battery electric and
hybrid electric vehicles the energy is stored in a battery or bank of
capacitors for later use. Energy may also be stored by compressing air
or by a rotating flywheel.

Regenerative braking is not the same as dynamic braking, which
dissipates the electrical energy as heat and does not maintain energy
in a usable form.

Bob Swinney
"Ignoramus4212" wrote in message
...
On 2010-03-13, Robert Swinney wrote:
A form of regen braking is available on some "diesel" locos. It consists of a huge bank of
resistors absorbing generated current from the DC traction motors. The resistors are housed in a
pod somewhere on the loco, usu. behind the cab near the top.

What you are describing is not regenerative braking.

i

Bob Swinney
"Ignoramus4212" wrote in message
...
On 2010-03-13, Steve B wrote:

"Greg O" wrote in message
...

"Robert Swinney" wrote in message
...
www.tornado1.wmv

Amazing video! Only a RR person would appreciate this; but the final
scene was of the broken-off
rear part of the train which continued down the track to collide with the
front half. Normally,
when a train breaks in two like that one, automatic air brakes are
applied to both portions.
Theoretically, both halves should come to full "emergency stop" to
prevent a reconnect disaster like
that one.

Bob Swinney


My bet the brakes applied just fine, but the veiw is rearward from the
locomotive, (or set of locos), which stopped right away as it just had
it's own momentum to stop, where the rest of the train had perhaps a mile
of cars to stop, and that is not going to stop quickly!

Don't forget the locomotive has dynamic braking, which is some sort of
electric talk for reducing the power to the motors, which slows them down
electrically, and not with friction.

Electric braking uses motors as generators, and dumps the energy into
big resistors.

Regenerative braking is only available on electrified railroads. It
also uses the motors as generators, but instead of just dumping elergy
into resistors, it returns them into the railroad's power system via
overhead cable.

i

Train wreck . . .
 

On 2010-03-13, Robert Swinney wrote:
Iggy,

What part of regenerative do you not understand?

See my other post with the link to Wikipedia.

What you described is called dynamic braking, not regenerative.

i

Bob Swinney
"Ignoramus4212" wrote in message
...
On 2010-03-13, Robert Swinney wrote:
A form of regen braking is available on some "diesel" locos. It consists of a huge bank of
resistors absorbing generated current from the DC traction motors. The resistors are housed in a
pod somewhere on the loco, usu. behind the cab near the top.

What you are describing is not regenerative braking.

i

Bob Swinney
"Ignoramus4212" wrote in message
...
On 2010-03-13, Steve B wrote:

"Greg O" wrote in message
...

"Robert Swinney" wrote in message
...
www.tornado1.wmv

Amazing video! Only a RR person would appreciate this; but the final
scene was of the broken-off
rear part of the train which continued down the track to collide with the
front half. Normally,
when a train breaks in two like that one, automatic air brakes are
applied to both portions.
Theoretically, both halves should come to full "emergency stop" to
prevent a reconnect disaster like
that one.

Bob Swinney


My bet the brakes applied just fine, but the veiw is rearward from the
locomotive, (or set of locos), which stopped right away as it just had
it's own momentum to stop, where the rest of the train had perhaps a mile
of cars to stop, and that is not going to stop quickly!

Don't forget the locomotive has dynamic braking, which is some sort of
electric talk for reducing the power to the motors, which slows them down
electrically, and not with friction.

Electric braking uses motors as generators, and dumps the energy into
big resistors.

Regenerative braking is only available on electrified railroads. It
also uses the motors as generators, but instead of just dumping elergy
into resistors, it returns them into the railroad's power system via
overhead cable.

i

Train wreck . . .
 

Sorry Iggy . . . .

I bow to your stand on semantics.

Bob Swinney
"Ignoramus4212" wrote in message
...
On 2010-03-13, Robert Swinney wrote:
Iggy,

What part of regenerative do you not understand?

See my other post with the link to Wikipedia.

What you described is called dynamic braking, not regenerative.

i

Bob Swinney
"Ignoramus4212" wrote in message
...
On 2010-03-13, Robert Swinney wrote:
A form of regen braking is available on some "diesel" locos. It consists of a huge bank of
resistors absorbing generated current from the DC traction motors. The resistors are housed in a
pod somewhere on the loco, usu. behind the cab near the top.

What you are describing is not regenerative braking.

i

Bob Swinney
"Ignoramus4212" wrote in message
...
On 2010-03-13, Steve B wrote:

"Greg O" wrote in message
...

"Robert Swinney" wrote in message
...
www.tornado1.wmv

Amazing video! Only a RR person would appreciate this; but the final
scene was of the broken-off
rear part of the train which continued down the track to collide with the
front half. Normally,
when a train breaks in two like that one, automatic air brakes are
applied to both portions.
Theoretically, both halves should come to full "emergency stop" to
prevent a reconnect disaster like
that one.

Bob Swinney


My bet the brakes applied just fine, but the veiw is rearward from the
locomotive, (or set of locos), which stopped right away as it just had
it's own momentum to stop, where the rest of the train had perhaps a mile
of cars to stop, and that is not going to stop quickly!

Don't forget the locomotive has dynamic braking, which is some sort of
electric talk for reducing the power to the motors, which slows them down
electrically, and not with friction.

Electric braking uses motors as generators, and dumps the energy into
big resistors.

Regenerative braking is only available on electrified railroads. It
also uses the motors as generators, but instead of just dumping elergy
into resistors, it returns them into the railroad's power system via
overhead cable.

i

Train wreck . . .
 

"Ignoramus4212" wrote in message
...
On 2010-03-13, Steve B wrote:

"Greg O" wrote in message
...

"Robert Swinney" wrote in message
...
www.tornado1.wmv

Amazing video! Only a RR person would appreciate this; but the final
scene was of the broken-off
rear part of the train which continued down the track to collide with
the
front half. Normally,
when a train breaks in two like that one, automatic air brakes are
applied to both portions.
Theoretically, both halves should come to full "emergency stop" to
prevent a reconnect disaster like
that one.

Bob Swinney


My bet the brakes applied just fine, but the veiw is rearward from the
locomotive, (or set of locos), which stopped right away as it just had
it's own momentum to stop, where the rest of the train had perhaps a
mile
of cars to stop, and that is not going to stop quickly!

Don't forget the locomotive has dynamic braking, which is some sort of
electric talk for reducing the power to the motors, which slows them down
electrically, and not with friction.

Electric braking uses motors as generators, and dumps the energy into
big resistors.

Regenerative braking is only available on electrified railroads. It
also uses the motors as generators, but instead of just dumping elergy
into resistors, it returns them into the railroad's power system via
overhead cable.

i

I watched a specials on trains, and they used Electromotive Diesels to power
electric motors on the wheels. They said during that time they used dynamic
braking.

Steve

Train wreck . . .
 

On Mar 13, 10:31*am, "Robert Swinney" wrote:
Some good stuff, Paul, but no cigar.

RR air brakes are applied by sensing (brake control) valves in each car. *As the engineer calls for
breaking he makes a "brake pipe reduction" in train line air of a graduated amount of psi. *The
reduction within the entre brake line is felt simultaneously in each car causing the brake control
valves to move an equivalent amount.
In turn the brake valves release a corresponding amount of air from double ended reservoirs which go
to brake cylinders. *To effect more braking, more train line pressure is reduced. *Loco engineers
speak of this as so many pounds of braking. *One of the down sides of this (Westinghouse AB system)
is that in order to release brakes, the train line pressure must be restored via main air reservoir
in the loco.

Slack action in long trains, particularly exacerbated by hilly terrain is a frequent cause of
drawbars and coupler breakage. *Depending on train length and other conditions, going to "Big Hole"
full emergency stop can be a dangerous thing. *Literally, the brakes have to be "pumped off" before
a train can be moved.

Bob Swinney

inet.com" wrote in message

...
On Mar 13, 8:26 am, "Steve B" wrote:



"Greg O" wrote in message

...

"Robert Swinney" wrote in message
m...
www.tornado1.wmv

Amazing video! Only a RR person would appreciate this; but the final
scene was of the broken-off
rear part of the train which continued down the track to collide with the
front half. Normally,
when a train breaks in two like that one, automatic air brakes are
applied to both portions.
Theoretically, both halves should come to full "emergency stop" to
prevent a reconnect disaster like
that one.

Bob Swinney

Thanks, Bob.
That does explain a lot of what I have observed.

The older son of my sister-in-law's neighbor is a train engineer for
the local railroad. He went through many months of class room and on-
job training before he could drive a train. A lot more complicated
than shown in the movies!

Paul

Train wreck . . .
 

Robert Swinney wrote:
www.tornado1.wmv

Amazing video! Only a RR person would appreciate this; but the final scene was of the broken-off
rear part of the train which continued down the track to collide with the front half. Normally,
when a train breaks in two like that one, automatic air brakes are applied to both portions.
Theoretically, both halves should come to full "emergency stop" to prevent a reconnect disaster like
that one.
Air brakes don't work that well when the wheels
are off the track! If you look down below the
tank car, the sparks seem to indicate at least
several cars of the rear portion have derailed.

Jon

Train wreck . . .
 

Robert Swinney wrote:
A form of regen braking is available on some "diesel" locos. It consists of a huge bank of
resistors absorbing generated current from the DC traction motors. The resistors are housed in a
pod somewhere on the loco, usu. behind the cab near the top.
Actually it is most of the roof of main line
locos. The Diesel radiators are the front 1/3 or
so, the back 2/3ds are the braking resistor array.
When you hear a loco pass and there is a loud
humming whir, that is mostly the fans on the
braking resistor grid. Our house is a mile from
the track, and those fans are the first thing I
hear coming, and I can hear them for quite some
time as the train passes.

Jon

Train wreck . . .
 

Ignoramus4212 wrote:
On 2010-03-13, Robert Swinney wrote:
A form of regen braking is available on some "diesel" locos. It consists of a huge bank of
resistors absorbing generated current from the DC traction motors. The resistors are housed in a
pod somewhere on the loco, usu. behind the cab near the top.

What you are describing is not regenerative braking.
Depends on how you define "regenerative". If it
means returning kinetic energy to form that is
then used by other vehicles, then no. If it means
turning kinetic energy into electrical energy,
then it is. Some locos now have flywheels or
ultracapacitor banks, but I suspect that is more
on passenger rail systems than freight.

Jon

Train wreck . . .
 

Steve sez: "I watched a specials on trains, and they used Electromotive Diesels to power
electric motors on the wheels. They said during that time they used dynamic
braking."

AFAIK, most EMDs still operate that way. There are (were ?) some diesel-over-hydraulic locos but
they are way out of my sphere of knowledge. In an EMD, Diesel engines drive generators which supply
power for traction motors on the axels. "Transmission effect" is done by changing the connectivity
scheme between the generators and traction motors. Large contactors are involved. When undergoing
transition, as it is called, it sounds to a bystander like the engine is shifting gears.

Bob Swinney



"Steve B" wrote in message ...

"Ignoramus4212" wrote in message
...
On 2010-03-13, Steve B wrote:

"Greg O" wrote in message
...

"Robert Swinney" wrote in message
...
www.tornado1.wmv

Amazing video! Only a RR person would appreciate this; but the final
scene was of the broken-off
rear part of the train which continued down the track to collide with
the
front half. Normally,
when a train breaks in two like that one, automatic air brakes are
applied to both portions.
Theoretically, both halves should come to full "emergency stop" to
prevent a reconnect disaster like
that one.

Bob Swinney


My bet the brakes applied just fine, but the veiw is rearward from the
locomotive, (or set of locos), which stopped right away as it just had
it's own momentum to stop, where the rest of the train had perhaps a
mile
of cars to stop, and that is not going to stop quickly!

Don't forget the locomotive has dynamic braking, which is some sort of
electric talk for reducing the power to the motors, which slows them down
electrically, and not with friction.

Electric braking uses motors as generators, and dumps the energy into
big resistors.

Regenerative braking is only available on electrified railroads. It
also uses the motors as generators, but instead of just dumping elergy
into resistors, it returns them into the railroad's power system via
overhead cable.

i


Steve

Train wreck . . .
 

"Jon Elson" wrote in message
...
Robert Swinney wrote:
www.tornado1.wmv

Amazing video! Only a RR person would appreciate this; but the final scene was of the broken-off
rear part of the train which continued down the track to collide with the front half. Normally,
when a train breaks in two like that one, automatic air brakes are applied to both portions.
Theoretically, both halves should come to full "emergency stop" to prevent a reconnect disaster
like
that one.
Air brakes don't work that well when the wheels
are off the track! If you look down below the
tank car, the sparks seem to indicate at least
several cars of the rear portion have derailed.

Jon

Train wreck . . .
 

Jon sez: "Air brakes don't work that well when the wheels
are off the track! If you look down below the
tank car, the sparks seem to indicate at least
several cars of the rear portion have derailed."

Right Jon. And they don't work all that well with everything in its place, either. I've heard it
said that "a mile long freight train, at speed, can't stop in it's own length"

Bob Swinney

"Jon Elson" wrote in message
...
Robert Swinney wrote:
www.tornado1.wmv

Amazing video! Only a RR person would appreciate this; but the final scene was of the broken-off
rear part of the train which continued down the track to collide with the front half. Normally,
when a train breaks in two like that one, automatic air brakes are applied to both portions.
Theoretically, both halves should come to full "emergency stop" to prevent a reconnect disaster
like
that one.

Jon

Train wreck . . .
 

Jon sez:

"When you hear a loco pass and there is a loud
humming whir, that is mostly the fans on the
braking resistor grid."

Not only braking resistors, Jon. In an EMD, most all electrical "heat" is removed by fans. The
traction motors have blowers, as well.

Once, I was privileged to watch load testing of brand new EMDs. All fan loads, traction motors,
etc. (Majority of electrical load) was disconnected from the main generators. The entire output of
the generators was fed to a massive bank of resistors. You can imagine 2000 - 4000 HP of heat. As
I recall, the resistor bank cooling was from huge fans, which were part of the electrical load. HP
was calculated by voltage x current from the generators.

Bob Swinney


"Jon Elson" wrote in message
...
Robert Swinney wrote:
A form of regen braking is available on some "diesel" locos. It consists of a huge bank of
resistors absorbing generated current from the DC traction motors. The resistors are housed in a
pod somewhere on the loco, usu. behind the cab near the top.
Actually it is most of the roof of main line
locos. The Diesel radiators are the front 1/3 or
so, the back 2/3ds are the braking resistor array.
Our house is a mile from
the track, and those fans are the first thing I
hear coming, and I can hear them for quite some
time as the train passes.

Jon

Train wreck . . .
 

The brakes are to help the train stopped when stopped. Not roll down a hill.
The brakes are not all that good to stop a train they just can't handle the
energy delivered upon demand.

That is why a number of people get run over in crossings - thinking the train
can stop. They will stop and back up.

Trains often have rear end pusher trains if on grades. The lead train
electronically controls it.

I know a SP train master and see him most days.

Martin

Robert Swinney wrote:
Jon sez: "Air brakes don't work that well when the wheels
are off the track! If you look down below the
tank car, the sparks seem to indicate at least
several cars of the rear portion have derailed."

Right Jon. And they don't work all that well with everything in its place, either. I've heard it
said that "a mile long freight train, at speed, can't stop in it's own length"

Bob Swinney

"Jon Elson" wrote in message
...
Robert Swinney wrote:
www.tornado1.wmv

Amazing video! Only a RR person would appreciate this; but the final scene was of the broken-off
rear part of the train which continued down the track to collide with the front half. Normally,
when a train breaks in two like that one, automatic air brakes are applied to both portions.
Theoretically, both halves should come to full "emergency stop" to prevent a reconnect disaster
like
that one.

Jon

Train wreck . . .
 

On 2010-03-14, Robert Swinney wrote:
Steve sez: "I watched a specials on trains, and they used Electromotive Diesels to power
electric motors on the wheels. They said during that time they used dynamic
braking."

AFAIK, most EMDs still operate that way. There are (were ?) some diesel-over-hydraulic locos but
they are way out of my sphere of knowledge. In an EMD, Diesel engines drive generators which supply
power for traction motors on the axels. "Transmission effect" is done by changing the connectivity
scheme between the generators and traction motors. Large contactors are involved. When undergoing
transition, as it is called, it sounds to a bystander like the engine is shifting gears.

Russian electric locomotives VL-80 use 12 kilos of silver in each
locomotive, for the transformer tap changer. I have no idea how they
keep that silver from being stolen.

i

Train wreck . . .
 

"Greg O" wrote in message
...

" wrote in message
...

The older son of my sister-in-law's neighbor is a train engineer for
the local railroad. He went through many months of class room and on-
job training before he could drive a train. A lot more complicated
than shown in the movies!

Paul

My dad worked for the Soo, (Soo Line fo the old timers here!), for over 40
years. He started on the section crew, repairing rail, and ended up as a
conductor at the end. I was fortunate as a child to go on the "road" with
him from time to time, long before all the rules and regs took over. I
remember a few times getting to run a train down the tracks. Yep! A
scrawny ten year old kid, sitting in the engineer's seat running the
speeds and braking on a mile long train! Of course the engineer was
looking over my shoulder giving me recommendations on speeds and braking.
It is quite a juggling act maintaining speed in hilly country, I never got
the hang of it! You need to anticipate when the bulk of the train is
coming over the hill top and heading down the grade and reduce speed
accordingly. Also the same for going up a grade and trying to figure out
when to increase the speed selector to maintain speed. I was always over
or under the recommended speed for the track, never did figure out the
seee-saw!
Greg O

my second father was an engineer for new haven/penn central/conrail. as far
as i know he worked his way up the ladder also to become an engineer. i
never got to operate an engine but i got to go inside an engine a few times,
i think i got a ride in the yard once too, got to toot the whistle
(lol)(late 70's). what wonderful memories (that well worn machine/diesel
smelling cab/controls). oh, and i got a ride in a caboose once too, wee!
(i have a vague memory that was a LONG ride, tens of miles). those guys
were real men's men (like apparently many of you guys here on this list).
as kids we hung out (as much as we could/were allowed to) at the rail yard
in maybrook ny (which, *VERY* sadly no longer exists).
one time, a few years after he died, i was in grand central terminal in new
york, was the early 80's. was with my then girlfriend. we were about to
board the train and i said to her "let's go say hi to the engineer". we
did. i yelled up to him asking him if he knew my father. he said "yeah, he
taught me everything i know" (which i kinda assumed he was just being
polite). he told us to come on up and in the engine. he let us ride in the
engine from grand central to white plains (i'm sure he could've gotten in
trouble). it was a BLAST. i remembered this story recently because of the
recent incident with the air traffic controller allowing his kid(s) to talk
over the radio. my belief is, things like that weren't such a big effin'
deal in the 70's. it was prolly unwise for the air traffic controller to do
so, but prolly in the 70's it wouldn't've made international news. if his
boss found out he probably would've gotten a reprimand and that's it. i'm
sure there's NO WAY an engineer would allow someone from "off the street"
ride in a commuter passenger train engine nowadays. lol.

b.w.

Train wreck . . .
 

"Ignoramus4212" wrote in message
...
On 2010-03-14, Robert Swinney wrote:
Steve sez: "I watched a specials on trains, and they used Electromotive
Diesels to power
electric motors on the wheels. They said during that time they used
dynamic
braking."

AFAIK, most EMDs still operate that way. There are (were ?) some
diesel-over-hydraulic locos but
they are way out of my sphere of knowledge. In an EMD, Diesel engines
drive generators which supply
power for traction motors on the axels. "Transmission effect" is done by
changing the connectivity
scheme between the generators and traction motors. Large contactors are
involved. When undergoing
transition, as it is called, it sounds to a bystander like the engine is
shifting gears.

Russian electric locomotives VL-80 use 12 kilos of silver in each
locomotive, for the transformer tap changer. I have no idea how they
keep that silver from being stolen.

i

Fear of vacationing at the Gulag Peninsula in the winter?

Steve

Train wreck . . .
 

On 2010-03-14, Steve B wrote:

"Ignoramus4212" wrote in message
...
On 2010-03-14, Robert Swinney wrote:
Steve sez: "I watched a specials on trains, and they used Electromotive
Diesels to power
electric motors on the wheels. They said during that time they used
dynamic
braking."

AFAIK, most EMDs still operate that way. There are (were ?) some
diesel-over-hydraulic locos but
they are way out of my sphere of knowledge. In an EMD, Diesel engines
drive generators which supply
power for traction motors on the axels. "Transmission effect" is done by
changing the connectivity
scheme between the generators and traction motors. Large contactors are
involved. When undergoing
transition, as it is called, it sounds to a bystander like the engine is
shifting gears.

Russian electric locomotives VL-80 use 12 kilos of silver in each
locomotive, for the transformer tap changer. I have no idea how they
keep that silver from being stolen.

i

Fear of vacationing at the Gulag Peninsula in the winter?


Considering how many other things that ends up stolen there, it has to
be something else.

Train wreck . . .
 

Steve sez:

"Fear of vacationing at the Gulag Peninsula in the winter?"

Naw! More'n likely the fear of electrocution on the spot. Pssst ! Don't let the ME terrorists
types know about that particular route to martyrdom. It could ruin their visit with the 72 virgins;
depending on which part of their anatomy they touched first.

Bob Swinney



"Steve B" wrote in message ...

"Ignoramus4212" wrote in message
...
On 2010-03-14, Robert Swinney wrote:
Steve sez: "I watched a specials on trains, and they used Electromotive
Diesels to power
electric motors on the wheels. They said during that time they used
dynamic
braking."

AFAIK, most EMDs still operate that way. There are (were ?) some
diesel-over-hydraulic locos but
they are way out of my sphere of knowledge. In an EMD, Diesel engines
drive generators which supply
power for traction motors on the axels. "Transmission effect" is done by
changing the connectivity
scheme between the generators and traction motors. Large contactors are
involved. When undergoing
transition, as it is called, it sounds to a bystander like the engine is
shifting gears.

Russian electric locomotives VL-80 use 12 kilos of silver in each
locomotive, for the transformer tap changer. I have no idea how they
keep that silver from being stolen.

i


Steve

Train wreck . . .
 

"Robert Swinney" wrote in message
...
Steve sez:

"Fear of vacationing at the Gulag Peninsula in the winter?"

Naw! More'n likely the fear of electrocution on the spot. Pssst ! Don't
let the ME terrorists
types know about that particular route to martyrdom. It could ruin their
visit with the 72 virgins;
depending on which part of their anatomy they touched first.

Bob Swinney



"Steve B" wrote in message
...

"Ignoramus4212" wrote in message
...
On 2010-03-14, Robert Swinney wrote:
Steve sez: "I watched a specials on trains, and they used Electromotive
Diesels to power
electric motors on the wheels. They said during that time they used
dynamic
braking."

AFAIK, most EMDs still operate that way. There are (were ?) some
diesel-over-hydraulic locos but
they are way out of my sphere of knowledge. In an EMD, Diesel engines
drive generators which supply
power for traction motors on the axels. "Transmission effect" is done
by
changing the connectivity
scheme between the generators and traction motors. Large contactors are
involved. When undergoing
transition, as it is called, it sounds to a bystander like the engine is
shifting gears.

Russian electric locomotives VL-80 use 12 kilos of silver in each
locomotive, for the transformer tap changer. I have no idea how they
keep that silver from being stolen.

i


Steve

With my luck, the 72 of them would all look like Hillary Clinton. Enough to
make one consider celibacy.

Steve

Train wreck . . .
 

" wrote in message
...

The older son of my sister-in-law's neighbor is a train engineer for
the local railroad. He went through many months of class room and on-
job training before he could drive a train. A lot more complicated
than shown in the movies!

Paul

My dad worked for the Soo, (Soo Line fo the old timers here!), for over 40
years. He started on the section crew, repairing rail, and ended up as a
conductor at the end. I was fortunate as a child to go on the "road" with
him from time to time, long before all the rules and regs took over. I
remember a few times getting to run a train down the tracks. Yep! A scrawny
ten year old kid, sitting in the engineer's seat running the speeds and
braking on a mile long train! Of course the engineer was looking over my
shoulder giving me recommendations on speeds and braking. It is quite a
juggling act maintaining speed in hilly country, I never got the hang of it!
You need to anticipate when the bulk of the train is coming over the hill
top and heading down the grade and reduce speed accordingly. Also the same
for going up a grade and trying to figure out when to increase the speed
selector to maintain speed. I was always over or under the recommended speed
for the track, never did figure out the seee-saw!
Greg O

Train wreck . . .
 

Steve B wrote:

Robert Swinney wrote:

Naw! More'n likely the fear of electrocution on the spot. Pssst ! Don't
let the ME terrorists types know about that particular route to martyrdom.
It could ruin their visit with the 72 virgins; depending on which part of
their anatomy they touched first.

With my luck, the 72 of them would all look like Hillary Clinton. Enough to
make one consider celibacy.


That would explain why they were virgins...


--
Lead free solder is Belgium's version of 'Hold my beer and watch this!'

Train wreck . . .
 

"Greg O" wrote


My dad worked for the Soo, (Soo Line fo the old timers here!), for over 40
years. He started on the section crew, repairing rail, and ended up as a
conductor at the end. I was fortunate as a child to go on the "road" with
him from time to time, long before all the rules and regs took over.

A lady I know who is about 65 tells stories of her dad who worked on the
railroad in Louisiana. The kids and mom used to get to come with him
sometimes, staying in the bunk cars. They were taught to hide when any
other train passed. But they did get to go visit Dad, then caught a freight
or passenger train back home to Oklahoma, IIRC. Ah, the good old days
before all the rules and regs.

How did we all ever live through them before all this protection?

Steve

Train wreck . . .
 

On 2010-03-13, Steve B wrote:

"Ignoramus4212" wrote in message
...
On 2010-03-13, Steve B wrote:

"Greg O" wrote in message
...

"Robert Swinney" wrote in message
...
www.tornado1.wmv

Amazing video! Only a RR person would appreciate this; but the final
scene was of the broken-off
rear part of the train which continued down the track to collide with
the
front half. Normally,
when a train breaks in two like that one, automatic air brakes are
applied to both portions.
Theoretically, both halves should come to full "emergency stop" to
prevent a reconnect disaster like
that one.

Bob Swinney


My bet the brakes applied just fine, but the veiw is rearward from the
locomotive, (or set of locos), which stopped right away as it just had
it's own momentum to stop, where the rest of the train had perhaps a
mile
of cars to stop, and that is not going to stop quickly!

Don't forget the locomotive has dynamic braking, which is some sort of
electric talk for reducing the power to the motors, which slows them down
electrically, and not with friction.

Electric braking uses motors as generators, and dumps the energy into
big resistors.

Regenerative braking is only available on electrified railroads. It
also uses the motors as generators, but instead of just dumping elergy
into resistors, it returns them into the railroad's power system via
overhead cable.

i

I watched a specials on trains, and they used Electromotive Diesels to power
electric motors on the wheels. They said during that time they used dynamic
braking.


What they would do with diesel locomotives, is use the traction motors
as generators, and dump energy into big resistor grids. Those were
mushroom shaped things on the roof of the engine, with big fans
cooling them as they would take heat out of the resistors. The beauty
of this method is that there is no wear of brakes or other mechanical
pieces during braking.

Some new railyard switchers, like "Green Goat", work like Toyota Prius
and charge battery banks during braking, instead of just heating
resistors. Probably save the railroad a bundle of money on fuel, as
switchers do not need a lot of continuous power, and they need to
start and stop all the time.

On electrified railroads, the energy from braking can be returned to
power lines to help run other trains.

i

Train wreck . . .
 

On Mar 14, 2:26*pm, Ignoramus27323 ignoramus27...@NOSPAM.
27323.invalid wrote:


On electrified railroads, the energy from braking can be returned to
power lines to help run other trains.

i

In the early part of the 20th century the Great Northern, I think it
was, ran two tracks from East of Stevens Pass to Everett Washington.
They used electric locomotives on that part of the track. A West-bound
train would wait at the tunnel until an East-bound train was ready to
begin ascending the mountain pass. Then the train going down the
mountain would generate power to help move the train going up the
mountain.

I suspect the Diesel-electric locomotive became powerful enough and
cheap enough to put the electrics out of business.

Paul

Train wreck . . .
 

wrote:
On Mar 14, 2:26 pm, Ignoramus27323 ignoramus27...@NOSPAM.
27323.invalid wrote:


On electrified railroads, the energy from braking can be returned to
power lines to help run other trains.

i


In the early part of the 20th century the Great Northern, I think it
was, ran two tracks from East of Stevens Pass to Everett Washington.
They used electric locomotives on that part of the track. A West-bound
train would wait at the tunnel until an East-bound train was ready to
begin ascending the mountain pass. Then the train going down the
mountain would generate power to help move the train going up the
mountain.

I suspect the Diesel-electric locomotive became powerful enough and
cheap enough to put the electrics out of business.

Paul

The Great Norther Railway's electrification in Washington state extended
only 73 miles from Wenatchee (east slope) to Skykomish (west slope) of
Steven's Pass in the Cascade Mountains. The electrification was never
extended to the coast.

The reason or the elctrifcation was to allow trains to pass through
"Cascade Tunnel", some two miles long, at the summit of the Cascades.
While it proved possible to run steam locomotives through this tunnel,
it was a dangerous business, and several crews and many passengers were
nearly asphyxiated. After these problems, and changing regulations, the
railroad decided to electrify the entire line over Steven's Pass.

The electrification started as a 3-phase synchronous system in 1909, but
this complicated system was converted to single phase a while before a
newer 8-mile tunnel opened in 1928.

This system used AC overhead, for easiest power distribution; and DC
traction motors in the locomotives. This system provided the (then) best
control and operating characteristics. The high voltage AC was first
dropped in voltage by a transformer in the loco, then the AC-DC
conversion was achieved by large rotary-converters (motor-generators) in
each locomotive. It was a heavy and complex system, but proven
technology, and used by several other railroads as well as the G.N.

A variety of lovomotives were used over the years, the largest being the
two huge W-1 class B-D+D-B units, the largest electric locos to operate
in North America.

This system was used extensively until 1956, when the electric wires
were removed. All Diesel operation through the tunnel was made possible
by installing a massive ventilation system that continues in use, with
improvements, today.

Oddly, the current railroad, BNSF, continues to study the possibility of
re-electrifying the line. The Dieselized Cascade Tunnel has now proven a
serious bottleneck with much increased rail traffic. It takes close to a
half-hour to clear the tunnel of Diesel fumes after each eastbound
(upgrade) train passes through. This must be done before another train
can enter the tunnel. Were the tunnel re-electrified, following trains
could move through much sooner, increasing traffic.

Dan Mitchell
============

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