train handling

[sooblue]

I grew up next to the eastern main line out of and into SOO's shorham yard in Mpls.
When the trains had to stop before entering the yard or when they stopped on the hill exiting the yard they were streched out. To get started again the engineer would back the train to bunch it up than start up forward. It was like listening to aproaching thunder as the cars hit the end of their slack. Couldn't they have stopped bunched up ? also when going through a sag how do you control the slack so as not to be too hard on the cars?
I have read that some engineers like to run their train bunched up and others streched out.
how is either accomplished and which would you do?

Thanks, mike

[Anonymous]

Mike, I'm not sure what "era" you saw this, but it does make a big difference. In the "steam days", you needed slack to get the train started. With diesels, the low speed pulling power would dictate that you kept the train stretched. Not an issue with a 20 car local, but if you have 100 cars, or so, you have to be VERY careful not to apply too much power until your whole train is moving. If you apply too much amperage, too fast, you will start pulling drawbars. Not a good thing.
Hope this answers your question.
Todd C.

[wabash1]

i myself like my train streched out. less chance of things going wrong.when you crest a hill i drop notches to keep the train streched out over the hill and only try to lose very little speed as i get to the bottom ill work it back out and keep it streched. there are some places where this isnt possible and you haft to bunch your train in dynamic to control the speed. when you start pulling again you work it out slowly. on short trains i will use air to keep it streched and control the speed.

[BRAKIE]

That is also called "shaking them loose". Now,when you are leaving the yard you have no idea if all the brakes are release.So the engineer would pull forward untill the train stalled,reverse,back to stall,foward to stall,he would remember the spot that he stalled and note the different stalled locations.Now when the caboose began to move the conductor would let the engineer know and all the brakes are release as the caboose was rolling,the engineer would then add throttle and head out of town.
I do not know for sure if they still do that today or not. Perhaps "J" can comment.

[wabash1]

we call that taking slack. its done only in places that you dont have good traction to get started. i did not comment on this earlier as its not a regular practice on this division.

[Anonymous]

You did'nt mention if the hill was acending or decending. Engineers had to be much more delicate with the 'slack' when they had a crew on a caboose. Controling the slack up hill, and down hill is accomplished mostly with the 'automatic' brake valve. All the newer engines now have a 'maintaining feature', so once you set the proper amount of air, it does'nt fluctuate. If you stop your train on a decending grade (with automatic), it will usually be 'bunched' unless the engineer set alot of automatic and dragged them down the hill as in power-braking (now discourged as fuel wasting). If you do'nt back-in to the train as you release the automatic air(on a decending grade), the head end could run out violently while the rear end is still somewhat set-up and planted. Thus the head end releases quicker than the rear-very easlily causing a break-in-two by 'getting a knuckle'. To wind up my long-winded rhetoric, using the auto brake system is the key to controling the train in a smooth fashion. Controling the slack is the most important part of the hog-heads job. This can be quite difficult on a steep decending mtn. grade for example with dips and sags as you described. Just a hair too much independent brake, or too much automatic at the wrong time to control slack will result in violent run-ins, or run-outs resulting in derailments from said run-ins, and break-in -two's from over stretching...Hommie

[Modelcar]

Now as we have no cabooses, if one is using the process of "shaking them loose"...how does the engineer know when he has all the slack out of the train and the end of the train is moving with all the brakes free...

QM

[sooblue]

The years were from 1955-1972 that I observed
"real close up" as we used to sit in the weeds or on the bank by the tracks.
The thunder occured weather they were starting up hill or down. I suppose that when the train stopped down hill it was bunched up and that was why it thundered on start up.
It was rare to see less than 100 cars go by.
With the end of train valve can you set the brakes from the rear of the train?
If not, would that be usefull to be able to?
And thanks by the way for your responses.
As long as you guys are Knowledgeable you might as well educate me.

[Jackflash]

Real good answers, although it didnt come up,
with distributed power we have had to re-think
the way we handle trains on hills, by the way,
with DP trains the air does set and release
at each DP consist, as well as on the head end
so your set and releases are much quicker than
with a convential train, and, with high horse-
power locomotives you'll use your dynamic brakes
a whole lot more than you'll use your air for
train control. jackflash

[Anonymous]

Fred feels the jolt and sends a train is moving signal to the head end device.

[Anonymous]

The only set you can do with a rear end device is an emergency application. I really don't see much advantage to setting the air at the end of the train.

[wabash1]

who is fred???

[Modelcar]

...Well, that sounds innovative, I didn't know FRED was capable of doing that. Thanks.

QM

[Anonymous]

Fred is the name of the rear end device. This forum won't let me say what the F stands for but the R is rear E is end D is device.

[sooblue]

Ok,
now we have to go into some basic mechanical instruction.
Does the entire trains brakes set at the same time? or does it set car by car.
My thought was that if the brakes were set from the rear end than each cars brakes would set one at a time from the rear keeping the cars streched out.
One other thought. are anti-lock braking systems in use on trains today?
Maybe one other thing. How many train crews miss the caboose?

[Anonymous]

No, the train brakes do not set at the same time. They set from front to rear (car by car) as the air goes through the train line. If the air was set from the rear there would be more drawheads and knuckles than you can shake a stick at! In order to keep the train stretched out, the engineer sets his minimum reduction (5-9 lbs) and normally keeps the throttle in notch 4. This notch is the optimum LOWEST position (so to speak) for stretch braking in order to have the slack stretched in the train. Once the speed comes down then the engineer can reduce his throttle. If he so chooses, after the minimum is set, the engineer can go for more air, while increasing the throttle, if the speed needs to come down faster. If that's the case the engineer needs to watch his amp meter at the same time. It's important for an engineer to know his territory so that he can minimize the buff/draft forces within his train. Passenger equipment is a different story, I can't help you on that.
As far as anti-lock brakes on trains - Don't we wish. Does the rear emergency from and EOT count? I don't know.
The Caboose - If we had the brakeman still and also had to walk the train. It would be a lot faster getting down the road after being stopped for a defect detector. They're still out there, only used as shoving platforms on class one's.

[sooblue]

Thanks,
minimum reduction puts just enough pressure on the brakes to cause a slowing of the wheels which would bunch up the cars except that the engine is still pulling at a rate that keeps the cars tought. It doesn't sound to me that you are going to slow the train down doing that. You negate the slowing of the cars in order the keep them streached out. No wonder it takes so long to stop a train. I think it would be better to have the trains brakes apply from the rear with a minimum reduction and than after the slack is out the real stopping can take place. OH WELL this is why I'm not an engineer.
I guess I need to some how experiance this first hand to really understand.
Mike

[wabash1]

if you are using engine brake ( independent) to control slack at what speeds are you doing this.

[oltmannd]

There are some passenger and transit braking systems with anti-slide capability. In fact, some of the technology dates back to the 30s. It may be possible to do anti-slide on frt cars if electronic braking comes to pass. Doubtful this will happen soon as RRs spent all their money on mergers and have little left for major initiatives.

[sooblue]

I would be fairly simple to have anti-lock braking on a passenger train set as each car has power running through it from the head end.
Freight would be tougher and so more expensive.
Would there be any value in being able to apply the brakes from either the front or the back as the engineer thought it best?
From the front and you bunch up, from the rear you stretch out the cars.
mike

[Anonymous]

Maybe with electronic brakes it could be arranged to start set up at the rear of the train. The advantage gained would be minimal because with electronic brakes there is not supposed to be much of a time lag between the front and rear of a train. With air brakes the air goes in and out through the engine the brakes set on each car as the air reduction gets to each car in a serial manner. To increase the speed of the brakes setting in the train air is also exhausted locally at each of the rail cars. Still the air is taken out of the first car and the first car sets first.

[oltmannd]

With electronic brakes, all brakes apply or release simultaneoulsy. That's because you no longer have to use a brake pipe reduction to tell each brake valve what to do - you send an electrical signal. The brake pipe exists only to supply air to power the brake cylinders.

[oltmannd]

You really wouldn't want your braking performance based on the existance of HEP. If the HEP went out and you were relying on it for you braking performance, you might not get stopped at the next stop signal! You could (and they did) rely on a battery in each car. In the "old days", passenger car electrical systems ran on batteries that were changed by an axle-powered generator on each car.

[sooblue]

If you were stoping fast the cars would slide on the rail anyway wouldn't they?
The way to stop the slack would be with air cylinders stiffining the knuckles and...Is it called draft gear? or beam that cushions the car on impact.
on truck pintle hitches there is a small air cylinder with a shoe that keeps the hitch tight until the trailer is unhooked.
Would there be any reason why that would not work on a larger scale?
It might even help to reduce cars getting popped out of the train in hard deceloration.

[Anonymous]

If you are slowing down that fast it would be wise to worry about weather your engines were going on the ground also.

[wabash1]

if you are slowing down that fast you dont have any buisness running a train anyways. applying the brakes from the rear is worthless in train handling. as it would couse more trains to be torn up. the terrain is more usefull in controlling speed and making planned stops.

[sooblue]

Quick stops do happen though don't they?
When you say it takes a train 1.5 miles to stop is that a normal controled stop or a emergency stop?
What possable improvement would give the engineer an edge in a quick stop.
How about a braking system that works on the rails rather than on the wheels, that would tend to slide if locked up? It would be one time use than you would have to replace the shoes but it would have been a life and death event so it would be worth it.

[wabash1]

the only quick stop is an emergency application. and i never place my train in emergency until i hit the car or trespasser. it would be useless to make an emergency application becouse someone is playing chicken with you. if you placed your train in emergency every time someone decided to see how close you could get to them or they try beating you at a crossing then you never get down the road. and if its a gas truck i hit i rather get clear of them anyways than be sitting in the fire ball. the braking systems on trains today are good. as far as life or death well i hit a trespasser that didnt get out of the way they lived but i bet they wont do that again. and the angel on there shoulder that day wish it had a differant assignment to.

[Anonymous]

I agree with "j" in his 5:48 am post. I would not place my train in emergency unless I thought or knew I had hit something. Also, "j" is correct that, when fuel or propane trucks are involved, a slow speed incident is far and away more hazardous to the train crew than one at speed. You're almost guaranteed to stop in the middle of the mess, thereby placing yourself and others in great danger of injury from fire. There is a much lower probablity that such a collision will derail you. It's possible, of course, but you're much better off away from the fire. I also would not place a train in emergency for a pedestrian, unless I thought or knew I hit them. One afternoon, I thought I hit a lady who had a grocery cart that had it's wheels stuck between the rail and crossing timber. She was trying to move the out of the way and actually disappeared from my view (on a low-nose yet). I had already made a first service application because I saw her at a distance and the train was stretched across five or six other crossings. That's when I went to emergency. I looked away and heard the train hit the cart. We stopped about 7 car lengths away. My conductor and I went back looking and were joined by a police officer. We never found the lady, but we did unstick her grocery cart. She must have jumped at the very last minute and didn't hand around.
I would make an immediate emergency brake application in order to avoid going by an unanticipated stop signal. They will drop on you from time to time, or, heaven forbid, the approach was missed. Making a desired emergency brake application is a tricky thing to do. No engineer likes to do that...it'll really get your heart rate going!

[Anonymous]

If I could see a reasonable distance I would not put a train in emergency on a signal that dropped in my face. I would grab full service and keep my hand on the handle. A service reduction gets the shoes against the wheels and if you put it emergency afterwards the stop will be almost as quick and a lot less likely to pile the train into the ditch.