ADMIN: Re: Re: Freight car distribution


Mike Brock <brockm@...>
 

Laramie Larry writes:

"Or maybe not: It turns out that the probability of 36 or more cars
is so low that Excel cannot calculate it. For example a 90 boxcar
train with a "mere" 20 or more SP boxcars would occur only once in
every 19.5 billion trains. Conclusion: This train could not have
occurred by chance alone. (A friend of mine who has lived in Laramie
all his life - in particular the 1940s and 50s - describes these cars
as a "transfer run".)"

Meaning what? While I do not know for certain the location, the train is a 4000 class [ Big Boy ] and a water tank is visible in 1953. The locomotive and date confines the train to the area between Green River and Cheyenne. My guess is that the location is Buford [ that vacation spa on the east side of Sherman Hill ]. I do not know the direction of travel. Incidentally, the first car is, I believe, a covered hopper followed by 36 reefers followed by the 36 SP box cars with a few others.

"Suppose that the 4% number is wrong; Tim Gilbert's data lists 4.9% SP-
Pac ownership in 1956".

Except that in 1953 the number should be 4.35% for 1953...assuming halfway between 52's 4.2% and '54's 4.5%.

"Let's be generous and make it 5%. Then a 90
car train would have 20 or more SP boxcars once in every 356 million
trains. (Tim's data are at "4060totalboxcarsUSownership.xls" in the
files section of this list.)

Rather than using the proportion of the national fleet, how about
giving more "weight" to SP cars on the UP because of the "connection"
between the two railroads, or because of nearness or whatever? Let's
say we "weight" the SP cars by a factor of two (Mike Brock suggests a
weight of 1.5)."

Actually I said:

"The model that I prefer is a modified Nelson/Gilbert model which states that
RRs with "significant interchange" should have from 2 to 2.5 times the
national %."

I may have said 1.5 at some point...

"To apply the desired weight, multiply it by the
national proportion: e.g., 2 * 5% = 10%. Using a "probability of
success on each trial" of 10% and a 90 boxcar train we find that
Excel still cannot calculate it because the probability is too low (a
train with "only" 30 or more SP boxcars would occur once every 3
billion trains). Conclusion: No reasonable weighting will reproduce
the train actually observed - we must reject the null hypothesis.
That is, the observed train composition is not the result of chance
alone."

My feeling as well. And, I notice the same thing with trains that are easier to identify...lumber laden eastbounds with 31 SP box cars for example.

Mike Brock


Dennis Storzek <destorzek@...>
 

--- In STMFC@..., "Mike Brock" <brockm@...> wrote:

Actually I said:

"The model that I prefer is a modified Nelson/Gilbert model which
states
that
RRs with "significant interchange" should have from 2 to 2.5 times the
national %."
I'm sure this is the key… I'm sure that after one applies a whole
bunch of "weighting factors" that account for proximity of other
roads, preferred interchange partners, preferred routes for "rollers",
etc, the little bit of traffic that's left will look quite similar to
the Gilbert / Nelson proportions. The problem is, those weighting
factors are going to be different for every stretch of railroad one
could possibly model. As examples, compare the Yosemite Valley, which
had almost no cars of its own, with the similar sized Greater Winnipeg
Water Works District Railway, which had, as far as I know, no reason
to handle a foreign car, since the line basically functioned as a
conduit to bring gravel from pits along the line into the city for use
by the local construction industry.

I would suspect that the closest to the "average" stretch of railroad
would be the NKP or Wabash; railroads smack dab in the middle of the
country that handled the largest proportion of overhead traffic vs.
loads originating and terminating on line. If one had good train
consists for those lines, perhaps that would be the place to start
trying to determine correction factors for proximity and connections
of the "average" railroad.

But why bother? Data for the average railroad is only going to be good
for someone who freelances, but even then you run into the problem
that if you model the Maumee, what the heck is the Wabash hauling if
all that traffic is on the Maumee? Even if you get what was actually
happening right, you then have to modify it again to take into account
the new player you added.

I personally think that time would be better spent studying the
prototype one is trying to model, identifying the consists of the
trains as best one can from consists, interchange statistics, photos,
movies, whatever is available, noting not only the overall car mix,
but specific instances of heavy concentrations, because those heavy
concentrations aren't random events, they MEAN something, and modeling
them helps to capture the feel of the prototype.

Dennis


laramielarry <ostresh@...>
 

--- In STMFC@..., "Mike Brock" <brockm@...> wrote:

Laramie Larry writes: (A friend of mine who has lived in Laramie
all his life - in particular the 1940s and 50s - describes these
cars as a "transfer run".)"

Meaning what? While I do not know for certain the location, the
train is a
4000 class [ Big Boy ] and a water tank is visible in 1953. The
locomotive
and date confines the train to the area between Green River and
Cheyenne. My
guess is that the location is Buford [ that vacation spa on the
east side of
Sherman Hill ]. I do not know the direction of travel.
Incidentally, the
first car is, I believe, a covered hopper followed by 36 reefers
followed by
the 36 SP box cars with a few others.> Mike Brock
I'm pretty certain the location is Speer and the train pulled by 4005
is westbound on track 3, which would have brought it through
Laramie. Incidentally, the water tower and some of the white
buildings are still there.

I'll ask my friend to define "transfer run" the next time I see him.

Best wishes,
Larry Ostresh
Laramie, Wyoming


Richard Hendrickson
 

On Aug 21, 2008, at 1:13 PM, Dennis Storzek wrote:

[snip]
I personally think that time would be better spent studying the
prototype one is trying to model, identifying the consists of the
trains as best one can from consists, interchange statistics, photos,
movies, whatever is available, noting not only the overall car mix,
but specific instances of heavy concentrations, because those heavy
concentrations aren't random events, they MEAN something, and modeling
them helps to capture the feel of the prototype.








Bang on, Dennis. Thank you for stating so succinctly the case for
researching the intended prototype intensively rather than getting
absorbed in abstract statistics. Not to say that the statistics
aren't enlightening, and that we shouldn't be grateful to those whose
research made them available. However, they're not especially useful
to a modeler, and may even be seriously misleading, until interpreted
in the light of everything else that can be learned about the traffic
on a particular RR at a particular place and time. I (and, I
suspect, many others on this list) would be relieved if this turned
out to be the last word on this subject, though I suspect that's too
much to hope for.

Richard Hendrickson


Stokes John
 

Amen, Richard and Dennis. What I was trying to say all along. This should satisfy everyone who has a dog in this hunt, recognizing each perspective as part of the whole, but not THE whole, makes sense, but probably won't.

John Stokes
Bellevue, WA



To: STMFC@...: rhendrickson@...: Thu, 21 Aug 2008 15:27:11 -0700Subject: Re: ADMIN: Re: [STMFC] Re: Freight car distribution




On Aug 21, 2008, at 1:13 PM, Dennis Storzek wrote:> [snip]> I personally think that time would be better spent studying the> prototype one is trying to model, identifying the consists of the> trains as best one can from consists, interchange statistics, photos,> movies, whatever is available, noting not only the overall car mix,> but specific instances of heavy concentrations, because those heavy> concentrations aren't random events, they MEAN something, and modeling> them helps to capture the feel of the prototype.>Bang on, Dennis. Thank you for stating so succinctly the case for researching the intended prototype intensively rather than getting absorbed in abstract statistics. Not to say that the statistics aren't enlightening, and that we shouldn't be grateful to those whose research made them available. However, they're not especially useful to a modeler, and may even be seriously misleading, until interpreted in the light of everything else that can be learned about the traffic on a particular RR at a particular place and time. I (and, I suspect, many others on this list) would be relieved if this turned out to be the last word on this subject, though I suspect that's too much to hope for.Richard Hendrickson


armprem
 

Dennis,I am in the process of a thorough study for a whole month for the
road that I am modeling.I am fortunate enough to have a relatively large
collection of wheel reports covering a period from 1942 to 1953.I personally
feel that the size and location of the road detirmines the traffic
pattern.We should also consider the time of the year and the size of the
sample being used.The proximity to Canada also must be considered in the
mix.Train # 9 has more Canadian box cars than any of the top 4 or 5 American
roads in the number of cars.Looking at loads actually carried show more
agricultural oriented products than industrial.Obviously the mix would not
be the same for a road in a heavily industrial area.While there have been
suggested other models for the mix,I choose to buy cars that I can verify
having been on the road for the period.A wheel report in one hand and an
ORER in the other provide me with the information I need before I make a
purchase Armand Premo

----- Original Message -----
From: "Dennis Storzek" <destorzek@...>
To: <STMFC@...>
Sent: Thursday, August 21, 2008 4:13 PM
Subject: ADMIN: Re: [STMFC] Re: Freight car distribution


--- In STMFC@..., "Mike Brock" <brockm@...> wrote:

Actually I said:

"The model that I prefer is a modified Nelson/Gilbert model which
states
that
RRs with "significant interchange" should have from 2 to 2.5 times the
national %."
I'm sure this is the key. I'm sure that after one applies a whole
bunch of "weighting factors" that account for proximity of other
roads, preferred interchange partners, preferred routes for "rollers",
etc, the little bit of traffic that's left will look quite similar to
the Gilbert / Nelson proportions. The problem is, those weighting
factors are going to be different for every stretch of railroad one
could possibly model. As examples, compare the Yosemite Valley, which
had almost no cars of its own, with the similar sized Greater Winnipeg
Water Works District Railway, which had, as far as I know, no reason
to handle a foreign car, since the line basically functioned as a
conduit to bring gravel from pits along the line into the city for use
by the local construction industry.

I would suspect that the closest to the "average" stretch of railroad
would be the NKP or Wabash; railroads smack dab in the middle of the
country that handled the largest proportion of overhead traffic vs.
loads originating and terminating on line. If one had good train
consists for those lines, perhaps that would be the place to start
trying to determine correction factors for proximity and connections
of the "average" railroad.

But why bother? Data for the average railroad is only going to be good
for someone who freelances, but even then you run into the problem
that if you model the Maumee, what the heck is the Wabash hauling if
all that traffic is on the Maumee? Even if you get what was actually
happening right, you then have to modify it again to take into account
the new player you added.

I personally think that time would be better spent studying the
prototype one is trying to model, identifying the consists of the
trains as best one can from consists, interchange statistics, photos,
movies, whatever is available, noting not only the overall car mix,
but specific instances of heavy concentrations, because those heavy
concentrations aren't random events, they MEAN something, and modeling
them helps to capture the feel of the prototype.

Dennis



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Robert kirkham
 

It's a bit of a relief to read this e-mail tonight!

I was starting to wonder about the proportions of railway specific freight car books in my collection. Do I have enough PRR, or NKP or ATSF or ..... gee, I wonder how many of you have an over representation of books on the Canadian freight car fleet? Come to think of it, it seems I may need something SP.....

Rob Kirkham (tongue in cheek)


From: Dennis Storzek

--- In STMFC@..., "Mike Brock" <brockm@...> wrote:

Actually I said:

"The model that I prefer is a modified Nelson/Gilbert model which
states
that
RRs with "significant interchange" should have from 2 to 2.5 times the
national %."
I'm sure this is the key. [snip]...

But why bother? Data for the average railroad is only going to be good
for someone who freelances, but even then you run into the problem
that if you model the Maumee, what the heck is the Wabash hauling if
all that traffic is on the Maumee? Even if you get what was actually
happening right, you then have to modify it again to take into account
the new player you added.

I personally think that time would be better spent studying the
prototype one is trying to model, identifying the consists of the
trains as best one can from consists, interchange statistics, photos,
movies, whatever is available, noting not only the overall car mix,
but specific instances of heavy concentrations, because those heavy
concentrations aren't random events, they MEAN something, and modeling
them helps to capture the feel of the prototype.

Dennis


Malcolm Laughlin <mlaughlinnyc@...>
 

--- In STMFC@..., Larry Jackman <Ljack70117@...> wrote:

At 6 AM each morning the entire yard was check and recorded on a
special form. Two copies were sent to the accounting department and
two copies to the car department and one filed in the files where
they were recorded.

This was done on the whole RR and was done on The Un Pac and John
Santa Fe.

It is of my opinion that this was done on every RR
in the good old US of A, So at 6 AM every freight car
in the good old US of A was on record.
I know for certain that it was not done on the NYC, MILW, NS or B&M.
The UP and ATSF were rather wealthy railroads, from long haul
revenue, and in the 60's were not known for keeping a sharp eye on
costs.

So they not only needed to be known, they were known.
That it was done does not tell us that it was needed. It sounds like
a want on the part of some official to give the car accounting
department a means for cross checking the data received from
interchange reports and wheel reports. Whether the costs saved by
having that cross reference exceeded the cost of all those yard clerk
hours is an interesting question.


Malcolm Laughlin <mlaughlinnyc@...>
 

Yes, Jack you are correct and those records for all railroads were forwarded to the car accounting offices. Most of the per diem was a paper exchange, but not all of it.
Not sure what you mean by this. All per diem was netted every month between every pair of railroads and money was exchanged. Except for the extremely inprobable event that two railroads had equla numbers of days of the other's cars for a month.

> Then of course there were the privately owned cars that were due their share as well.
Greg Martin
--------------------------------------

Privately owned cars were a very different thing. There was nothing analogous to the per diem settlement. Each railroad paid the owner of each car. For per diem, the critical document was the interchange report. For mileage cars the key accounting source document was the wheel report.


Malcolm Laughlin, Editor 617-489-4383
New England Rail Shipper Directories
19 Holden Road, Belmont, MA 02478


Steve Lucas <stevelucas3@...>
 

--- In STMFC@..., "Malcolm Laughlin" <mlaughlinnyc@...>
wrote:
CN did a systemwide 8 AM check in the era of STMFC.

Steve Lucas.

--- In STMFC@..., Larry Jackman <Ljack70117@> wrote:

At 6 AM each morning the entire yard was check and recorded on a
special form. Two copies were sent to the accounting department
and
two copies to the car department and one filed in the files where
they were recorded.

This was done on the whole RR and was done on The Un Pac and John
Santa Fe.

It is of my opinion that this was done on every RR
in the good old US of A, So at 6 AM every freight car
in the good old US of A was on record.
I know for certain that it was not done on the NYC, MILW, NS or
B&M.
The UP and ATSF were rather wealthy railroads, from long haul
revenue, and in the 60's were not known for keeping a sharp eye on
costs.

So they not only needed to be known, they were known.
That it was done does not tell us that it was needed. It sounds
like
a want on the part of some official to give the car accounting
department a means for cross checking the data received from
interchange reports and wheel reports. Whether the costs saved by
having that cross reference exceeded the cost of all those yard
clerk
hours is an interesting question.


devansprr
 

--- In STMFC@..., "Gatwood, Elden J SAD "
<elden.j.gatwood@...> wrote:
Oh, I also wrote a multi-piece article on what I did for my
timeframe and
locale, in TKM, and there was only one person even vaguely
interested. I
think I could have better spent my time (hundreds of hours) building
more
models!

Elden Gatwood
Elden,

I read your article, and Bruce's, on car distribution and found it
informative, especially in the area of what to consider when analyzing
the issue. It is a tough subject to cover - I'm planning a layout
focused on WWII and the main line, with branches that primarily served
coal mines. Therefore the specific information in your article does
not directly apply to my situation, but the process you went through
was educational. So that makes at least 2 who found it helpful. I'm
sure there must be more, so please do not dispair!

I hope to do some XM distribution analysis of the Potomac yard data in
the group files since that was a PRR interchange point and may provide
some insight into the issue, even though it is a few years late for me.

Regards,
Dave Evans