Western Railroad Discussion > Measuring Train Length

All:

We all know that train length is used by all of the railroads for all kinds
of operating purposes, like determining if a train will fit in a siding.
And, some years back, simply using the car count was replaced in favor of
using the physical length (say in feet). And well so, since the lengths of
individual cars began to vary widely from old forty foot boxes to newer
eighty-nine foot TOFC flats and five-platform double stacks.

And I also see now that engineers have distance counters on their desk top
control stands. They can zero out, then watch it count up so that they
know when their cabooseless rear end is by a switch or a slow order.

Good.

But (being part of the surveying profession) my question is: how is the
train's actual length determined to begin with? Is it physically measured?
Do departure tracks in a yard have calibrated locations for distance? Is
it a theoretical sum of individual car lengths taken from a database?
Anybody know how the length of a 4952 foot train was determined?

Thanks for the insight.

Gerry,
Martinez CA

to add to the questions: How is slack figured?

salsig Wrote:
-------------------------------------------------------
> >
> And I also see now that engineers have distance
> counters on their desk top
> control stands. They can zero out, then watch it
> count up so that they
> know when their cabooseless rear end is by a
> switch or a slow order.
>
> Good.
>
> But (being part of the surveying profession) my
> question is: how is the
> train's actual length determined to begin with?
> Is it physically measured?

No.
> Do departure tracks in a yard have calibrated
> locations for distance?

Yes.
Is it a theoretical sum of individual car lengths
> taken from a database?

Yes, again.
>
Anybody know how the length of a 4952 foot train
> was determined?
>
> More correctly, as a yardmaster builds a train the predetermined length of each car, which is in the railroads mainframe computer is added cumulatively to a running total. When the maximum desired length is reached, in your example 4952 feet, the YM has a choice; don't add any more cars to this train, run another train if traffic warrants, add left over cars to another train headed in the same direction. Many parameters exist such as footage, tonnage, available horsepower to run the train, available crews to operate the train(s) etc.>

joemagruder Wrote:
-------------------------------------------------------
> to add to the questions: How is slack figured?

I don't know of any 'official' formula. Experience with various types of equipment guides me. Cusion underframe cars have lots of drawbar slack. 5 pak intermodal have very little. Of course, all cars have a couple inches of 'free' slack that is the distance between pulling faces while in draw (pulling) and buff (being shoved).

Well there two ways that railroads use to determind train length. One is that when a train is either made up in a yard or passes a ACI reader, the consist of the train is updated in the railroad's mainframe computer. There is a national database of each piece of rolling stock in the US (an off shoot of the old Offical Railway Equipment Catalog). This database contains key measurements of these cars, particularly it's length between pulling faces (the inside of the knuckle). So when the train consist is updated, the railroad's mainframe consults with the national database to tally a sum length of the cars and locomoties in the train to get a length. But this length is only acurate if the consist is acurate. God only knows how many misroutes end up in trains on a daily basis, so leaving a yard a train could be several hundred feet longer than what is shown on the crew paperwork. It's not until the train passes a ACI reader that the actual consist of a train can be assured (at least to the degree that no one car in the train is missing both of it's ACI tags).

The other method is the locomotive counter which measure the actual physical length of a train. This method can only be used with a outside observer who can relay via radio when the rear of the train has passed a certain measuring point. A common use is when two train meet at a siding, the engineer will start the counter when the front of his locomotive passes the front of the opposing train's locomotive. The engineer of the opposing train will then relay when the last car passes the front of his locomotive.

Supposedly there are FRED out there now that can measure train length. But I do not know how that system works, or how accurate it is.

Ted Curphey
funnelfan@yahoo.com

What is a ACI reader? I have heard of AEI readers.

TIA,
Tim

cewherry Wrote:
-------------------------------------------------------
> joemagruder Wrote:
> --------------------------------------------------
> -----
> > to add to the questions: How is slack
> figured?
>
> I don't know of any 'official' formula. Experience
> with various types of equipment guides me. Cusion
> underframe cars have lots of drawbar slack. 5 pak
> intermodal have very little. Of course, all cars
> have a couple inches of 'free' slack that is the
> distance between pulling faces while in draw
> (pulling) and buff (being shoved).

As Mr Wherry mentioned, the train length comes from the railroad's database of equipment information which contains the cars overall length. As for the "slack" amount, it varies by road. Most roads will use 3%, but some (Alaska RR for one) opts for 5%. Every road has a format for a train consist printout that they like, so this really does vary a lot by road.

whoops, I meant AEI readers. ACI readers were the experiment tried out in the 1970's using colored bars on a black patch. Similar system, but unsuccessful.

funnelfan Wrote:
-------------------------------------------------------
>... But this length is only
> acurate if the consist is acurate. God only knows
> how many misroutes end up in trains on a daily
> basis, so leaving a yard a train could be several
> hundred feet longer than what is shown on the crew
> paperwork. It's not until the train passes a AEI
> reader that the actual consist of a train can be
> assured (at least to the degree that no one car in
> the train is missing both of it's AEI tags).

A crew leaving a terminal with "extra" cars that aren't on their paperwork is a potentially major rule violation and is not something that should occur very frequently. If a crew really tried to leave a terminal with a dozen or so extra cars than what was on their paperwork they'd be in big trouble. This is not to say it doesn't happen, but this is pretty rare. Misroutes are different, taking a car the wrong way or place happens all the time, but the car will show on the list.

They may use the AEI read to resequence a list, but the rules require an accurate consist with proper haz mat information when the train leaves a terminal. Also, AEI isn't all that accurate, the average misread percentage is around 2 to 3%, it just saves on clerk keystrokes.

Actually the crew is only responsible for checking the head cars, we have no idea and no way of knowing if the train consists of just the cars that are on the wheel. Now on NS when a train goes over a scanner they can get a printout of the consist and can radio the conductor the information to make adjustments, if necessary. These is also a thing called a radio waybill as well and this is used when the extra cars are hazmat, dangerous, etc.

Also, it is NOT the crew that is in trouble, if it is over the head six cars. It is the railroad that will have to answer to the FRA or the public utilities commission in what ever state this happens in. And, if a crew member is in trouble it is ONLY the conductor, the engineer is NOT responsible with regard to checking the head cars...

DB

DenisFBlake Wrote:
-------------------------------------------------------
> Actually the crew is only responsible for checking
> the head cars, we have no idea and no way of
> knowing if the train consists of just the cars
> that are on the wheel. Now on NS when a train
> goes over a scanner they can get a printout of the
> consist and can radio the conductor the
> information to make adjustments, if necessary.
> These is also a thing called a radio waybill as
> well and this is used when the extra cars are
> hazmat, dangerous, etc.

I wasn't aware the FRA was allowing a radio waybill. Last I talked to them they still wanted a paper copy.

>
> Also, it is NOT the crew that is in trouble, if it
> is over the head six cars. It is the railroad
> that will have to answer to the FRA or the public
> utilities commission in what ever state this
> happens in. And, if a crew member is in trouble
> it is ONLY the conductor, the engineer is NOT
> responsible with regard to checking the head
> cars...
>
> DB


True, although there are lots of exceptions to this, if the crew makes a willful violation then they're the one who gets nailed. The crew still has to worry about car placement (don't put the explosives next to a PIA, etc.)

And, you're right about the conductor, that's why he's the "brains".

Waybiller Wrote:
-------------------------------------------------------
> A crew leaving a terminal with "extra" cars that
> aren't on their paperwork is a potentially major
> rule violation and is not something that should
> occur very frequently. If a crew really tried to
> leave a terminal with a dozen or so extra cars
> than what was on their paperwork they'd be in big
> trouble. This is not to say it doesn't happen,
> but this is pretty rare. Misroutes are different,
> taking a car the wrong way or place happens all
> the time, but the car will show on the list.

Snip>>>>

I remember last yeay when the yard crew in Klamath Falls,OR, added 10 cars BEHIND the already attached FRED.(I didn't know it was possoble!). Just before the South-bound train got to Bieber,CA, the crew onboard got a call from the DS....the exchange went something like this;

DS...BNSF #### are you having problems with your FRED?
Crew..No
DS... Do you have ALL your cars?
Crew..Yes we do, the last detector gave a correct axel count.
(they had only passed one talking detector after leaving KLF)
DS....Thats funny, my print-out from that detector says you are short 10 cars!
Crew...NO WAY (politely!!)
DS....let me check, I'll get back to you...
Somewhat later....
DS.....BNSF ####
Crew...Yes?
DS...Further checking has revealed that the yard crew in KLF ADDED 10 cars behind your FRED.....the train behind you "found" them sitting at mp ### on the mainline.
Crew..Holy Cow!!!!
DS.... The track up there is a little rough, maybe???
Crew...Well, usually the pull-aparts are on North-bounds with auto racks.....



DaveL

DaveL Wrote:
-------------------------------------------------------
> Snip>>>>
> I remember last year when the yard crew in Klamath
> Falls,OR, added 10 cars BEHIND the already
> attached FRED.(I didn't know it was possoble!).
> Just before the South-bound train got to
> Bieber,CA, the crew onboard got a call from the
> DS....

All I can say is that life is different on the Class 1s these days.

DaveL Wrote:
-------------------------------------------------------
> Waybiller Wrote:
> --------------------------------------------------
> -----
> > A crew leaving a terminal with "extra" cars
> that
> > aren't on their paperwork is a potentially
> major
> > rule violation and is not something that
> should
> > occur very frequently. If a crew really
> tried to
> > leave a terminal with a dozen or so extra
> cars
> > than what was on their paperwork they'd be in
> big
> > trouble. This is not to say it doesn't
> happen,
> > but this is pretty rare. Misroutes are
> different,
> > taking a car the wrong way or place happens
> all
> > the time, but the car will show on the list.
>
> Snip>>>>
>
> I remember last yeay when the yard crew in Klamath
> Falls,OR, added 10 cars BEHIND the already
> attached FRED.(I didn't know it was possoble!).
> Just before the South-bound train got to
> Bieber,CA, the crew onboard got a call from the
> DS....the exchange went something like this;
>
> DS...BNSF #### are you having problems with your
> FRED?
> Crew..No
> DS... Do you have ALL your cars?
> Crew..Yes we do, the last detector gave a correct
> axel count.
> (they had only passed one talking detector after
> leaving KLF)
> DS....Thats funny, my print-out from that detector
> says you are short 10 cars!
> Crew...NO WAY (politely!!)
> DS....let me check, I'll get back to you...
> Somewhat later....
> DS.....BNSF ####
> Crew...Yes?
> DS...Further checking has revealed that the yard
> crew in KLF ADDED 10 cars behind your FRED.....the
> train behind you "found" them sitting at mp ### on
> the mainline.
> Crew..Holy Cow!!!!
> DS.... The track up there is a little rough,
> maybe???
> Crew...Well, usually the pull-aparts are on
> North-bounds with auto racks.....
>
>
>
> DaveL
>
>
See what computers have done for us! I remember when trains arrived short of cars, not over. A Milwaukee freight arrived at Pig's Eye minus one refer. The conductor recalled, "Yeah, we had a break-in-two about 40 miles back. We recoupled, tied the air and brought it in." Next day, the section found a refer half loaded with meat that had started swinging and threw the whole car, trucks and all, off the side of the ROW.

The DD gives you an axle count which you check with your consist. If you have less cars than you should have, no big deal, just tell the DS when you get a chance and keep rolling.

If you have extra cars, the you tell the DS and the chief looks it up and tells you what they are and where in your train. If dangerous, you take a radio waybill.

On CSX, you are supposed to stop within five miles if the DS can't identify them sooner, and either wait or walk the train, but that gets fudged a lot. When it was still CR, you just kept going and let the back room worry about it.

DenisFBlake Wrote:
-------------------------------------------------------
> Actually the crew is only responsible for checking
> the head cars, we have no idea and no way of
> knowing if the train consists of just the cars
> that are on the wheel. Now on NS when a train
> goes over a scanner they can get a printout of the
> consist and can radio the conductor the
> information to make adjustments, if necessary.
> These is also a thing called a radio waybill as
> well and this is used when the extra cars are
> hazmat, dangerous, etc.

I wasn't aware the FRA was allowing a radio waybill. Last I talked to them they still wanted a paper copy.

A radio waybill is a paper copy..you use information that this dispatcher or on NS, cyo, gave you over the radio. you fill in a radio waybill form, adjust your wheel and make it part of the wheel report..Very simple to do.

db