Push-Pull More Dangerous?

Tell us where you were and what you saw!

Moderator: David Benton

Push-Pull More Dangerous?

Postby BostonRailFan » Sat Jan 29, 2005 1:30 am

What do you guys think about this? It did come to my mind also. Would the Metrolink accident in California have been as bad if the engine was in front? I got a feeling it might have not been so devastating after seeing the computer generated reenactment which showed a great deal of buckling. Is engine forward operation with a modern day "cowcatcher" the answer?
======================================
Train Wreck Highlights Vulnerabilities

By GILLIAN FLACCUS
.c The Associated Press
(truncated)

Wednesday's crash also highlighted the practice of using locomotives at the rear of the train, to push it instead of pull it. To save time, commuter railroads such as Metrolink do not switch engines around when a commuter train reverses direction.

Smith said putting a passenger cab at the front makes a train more likely to derail instead of sweeping obstacles aside. Also, the force of a powerful engine in the back can cause a train to buckle violently in an accident, he said.

Flatau, the Federal Railroad Administration spokesman, said there is no evidence that a locomotive in the rear is more dangerous.
BostonRailFan
 

Postby Avro Arrow » Sat Jan 29, 2005 7:29 am

I think this may result in the push pull idea being reexamined. I'll stop short of saying they'll put an engine on each end. It will be interesting to see what happens.
Avro Arrow
 

Postby The S.P. Caboose » Sat Jan 29, 2005 11:50 am

I think it is more dangerous in push mode. If I seat in the cab car and see the engineer running out of there, I;m going to follow him to a safer place on the train.

I don't know what's coming out of this tragedy as far as engine placement.
The S.P. Caboose
 

Postby slotcanyoneer » Sun Jan 30, 2005 3:43 pm

Maybe they should start converting old engine units to control cars like Amtrak does. Although I really don't know much about Metrolink so I have no idea if that is financially possible or not.Just an idea.
slotcanyoneer
 

Postby Lehigh Valley Railroad » Mon Jan 31, 2005 12:49 am

It is more dangouroues, no doubt about that... manpower vs. new equipment... talk to the bean counters on that one.
Lehigh Valley Railroad
 

Postby Engineer Spike » Fri Feb 18, 2005 5:37 pm

I think that the FRA will require better crash resistance in cab cars, just like in locomotives. My uncle always liked the fact that the LIRR used the FA power cars as cab cars. He felt that he would have a better chance of surviving a crash.
Engineer Spike
 
Posts: 1662
Joined: Tue Mar 16, 2004 3:24 pm

Postby AMoreira81 » Fri Feb 25, 2005 3:46 pm

slotcanyoneer wrote:Maybe they should start converting old engine units to control cars like Amtrak does. Although I really don't know much about Metrolink so I have no idea if that is financially possible or not.Just an idea.


Their fleet is similar to, if not exactly like, the Trinity Railway Express fleet

Image

Given the size of the fleet (and Metrolink's), it may not be feasible to run pull-pull on commuter rail. However, single-deck cars may not have had the same effect as a double decker.
AMoreira81
 

Postby DutchRailnut » Sat Feb 26, 2005 9:05 am

Cab cars are not any more dangerous than an MU car or a bus for that matter.
The crush load strenght on frame of a locotive and the colission post on a cab car are same as on a locomotive.
In USA about 300 cab cars are in daily operation, each making at least 3 trips daily in push mode.
Each cab car passes over 20 or so crossings daily. so with these odds are cab cars more dangerous ?? no way.
I work cab cars every day and never hesitate to go to work.
If Conductors are in charge, why are they promoted to be Engineer???

Retired Triebfahrzeugführer
User avatar
DutchRailnut
 
Posts: 21230
Joined: Thu Mar 11, 2004 8:02 pm
Location: released from Stalag 13

Postby Avro Arrow » Sat Feb 26, 2005 11:46 pm

DutchRailnut wrote:Cab cars are not any more dangerous than an MU car or a bus for that matter.

Actually, they are. On a MU trainset (at least the ones I know of), there is power on every axle (or on the leading car). The power is throughout the trainset or on the front, like a conventionally-powered train.

The problem with push mode isn't the crush load strength, it's where the force is being applied. If you have an engine up front and strike an object, the force moving the train (the engine) directly impact the object. If it's in push mode, though, you have relatively light cars between a static object and several thousand horsepower. This alone can cause the cars to accordion and derail regardless if they are physically crushed. In other words, a grade crossing strike will compress the cars and potentially derail them (as in the Metrolink crash). The alternative is to have a much more massive locomotive (and all the power) up front, which makes the likelihood of a derailment much less in the even of a road strike.

Sometimes the force of the train is enough to overcome the object, and sometimes it isn't. Obviously in California a month ago, it wasn't.
Avro Arrow
 

Postby AMoreira81 » Sat Feb 26, 2005 11:55 pm

That is probably why the MTA LIRR will NOT allow customers into the front car of a push-pull train of 3 cars or more. That way, liability is reduced. However, few othe railroads have done this.
AMoreira81
 

Postby StevieC48 » Sun Feb 27, 2005 2:50 am

I recall a tragic accident"forgive me in the details" on the MBTA's Rockport/Ipswich Line when the T got the "new" 1300's pullman standards "comet cars" at the time. In the late 70's. The train was moving at the time(cab forard)when a B&M GP-9 making a freight move hit the cab car head on. The result of the accident was the engineer of the passenger train was killed instantly. The car was closed so no passengers were not seriously injured. The GP-9 tore through the cab car teliscoping the car up in the air complely slicing through the underfame and floor stopping before the second car. Please help if any one remembers this incident please add any detail I missed or screwed up on. Thanks Stevie
Farewell old friend thanks for the memories.
#4 EBT cars Hawker Siddley 1978-2009

Instructor/Inspector SERY
Member 25 years proud
User avatar
StevieC48
 
Posts: 1635
Joined: Fri Jun 18, 2004 8:43 pm
Location: Taunton, MA

Postby DutchRailnut » Sun Feb 27, 2005 12:11 pm

When a significant object is hit it realy does not matter if a locomotive or cab car is up front. in case of locomotive the resulting fire from the crash will probably increase the casualty figure.

When the engineer dumps the train , there is no more power on any of axles as the PCS knocks locomotive off line and to Idle.
each car and locomotive has the same brake rate as long as all wheels stay on rail..
If the brake were not applied yes the mass of the 120 ton locomotive would be a disadvantage.

In the Metro link crash the casualties were not in front of the cab car, but spread troughout the train.
If Conductors are in charge, why are they promoted to be Engineer???

Retired Triebfahrzeugführer
User avatar
DutchRailnut
 
Posts: 21230
Joined: Thu Mar 11, 2004 8:02 pm
Location: released from Stalag 13

Postby Avro Arrow » Sun Feb 27, 2005 1:19 pm

DutchRailnut wrote:When a significant object is hit it realy does not matter if a locomotive or cab car is up front. in case of locomotive the resulting fire from the crash will probably increase the casualty figure.

Right, because a locomtive bursting into flames in a huge fireball/mushroom cloud happens all the time when cars are hit at crossings.

When the engineer dumps the train , there is no more power on any of axles as the PCS knocks locomotive off line and to Idle.
each car and locomotive has the same brake rate as long as all wheels stay on rail..
If the brake were not applied yes the mass of the 120 ton locomotive would be a disadvantage.

Even when stopping, the locomotive is still more more massive than the cars themselves, which led to the accordion-type derailment. Had the an engine been up front, there is an extremely large chance that the locomotive would have sliced right on through the car without jumping the tracks... like freight trains. Even when striking much more formidable vehicles at crossings (such as log trucks), the locomotives rarely leave the rail.

In the Metro link crash the casualties were not in front of the cab car, but spread troughout the train.

Doesn't really matter where they were; had a locomotive been up front, the likelihood of a derailment would have been lessened and the Metrolink incident wouldn't have made the news.
Avro Arrow
 

Postby Avro Arrow » Thu Mar 03, 2005 11:32 pm

David Telesha wrote:Really? All the time? Maybe in Hollywood. I've seen plenty of hits and I never recall any exploding even with the train impacting at 70MPH. If anything it would be the auto that explodes not the locomotive - unless its tank was punctured.

Most of the damage on the Metrolink cab was from impacting the other train not from hitting the truck.

That was sarcasm Image
Avro Arrow
 

Postby DutchRailnut » Fri Mar 04, 2005 9:44 pm

Your Sarcasm is noted Avro Arrow, but How many trains or locomotives did you operate so far ?? ????
I got 22 years in rail industry and an other 12 in ships.
The Metro link accident would most cerainly have resulted in a fire.
lets see first the train hit a Jeep that was off the crossing towards the train.
second after running over the jeep the lead unit derailed (yes the locomotive would have derailed too).
Then the derailed unit veered into a siding, where it hit a work train that was stopped and had brakes applied.
The force was hard enough to knock the work train engine over and half way around.
The rear of train at impact derailed and fouled the other track were oposite train hit it.
somewhere along the line the fuel tank would have been crushed or cracked and the fuel ignited.
If Conductors are in charge, why are they promoted to be Engineer???

Retired Triebfahrzeugführer
User avatar
DutchRailnut
 
Posts: 21230
Joined: Thu Mar 11, 2004 8:02 pm
Location: released from Stalag 13

Next

Return to Travel & Trip Reports

Who is online

Users browsing this forum: No registered users and 2 guests