Date   
Re: Freight Car Distribution on smaller RRs

Anthony Thompson <thompson@...>
 

Dave Evans wrote:
Because the PRR would load as many of their cars as possible, many of them would hit interchange roads in higher than the national percentage rates (and vice-versa).
Is this supposition, Dave, or do you have a factual basis for it? Loading homeward-bound foreign empties was preferred under the car-handling rules, and though we know that most yard and local crews cold not have cared less about those rules, the rules nevertheless did bias empty assignments in that direction. That's why I'm interested if you have some data in support of your statement.

Tony Thompson Editor, Signature Press, Berkeley, CA
2906 Forest Ave., Berkeley, CA 94705 www.signaturepress.com
(510) 540-6538; fax, (510) 540-1937; e-mail, thompson@...
Publishers of books on railroad history

Re: Freight Car Distribution on smaller RRs

Anthony Thompson <thompson@...>
 

Ray Breyer wrote:
And the point flies completely out the window if you model the MWR as an online shipper, for any one of the three railroads that connected with them in central Indiana. The same applies to other "novelty" shippers like the C&IM, MRS, or anyone else with a fleet of semi-captive service boxcars, thus completely screwing up the Gilbert-Nelson model.
Not so, Ray. Go back and read Tim Gilbert's many thoughtful posts about this. He is talking about the cars from OUTSIDE the immediate area of a particular railroad--or what crystallographers call "next nearest neighbors," those beyond the nearest neighbors.

Essentially, the G-S hypothesis is a useful STARTING POINT for assembling a boxcar fleet.
Exactly what Tim and Dave have always said.

Tony Thompson Editor, Signature Press, Berkeley, CA
2906 Forest Ave., Berkeley, CA 94705 www.signaturepress.com
(510) 540-6538; fax, (510) 540-1937; e-mail, thompson@...
Publishers of books on railroad history

Re: Freight Car Distribution on smaller RRs

devansprr
 

--- In STMFC@..., "A. Premo" <armprem@...> wrote:

Dave,Which road do you model?Armand Premo
----- Original Message -----
From: "devansprr" <devans1@...>
To: <STMFC@...>
Sent: Wednesday, February 04, 2009 7:18 PM
Subject: [STMFC] Re: Freight Car Distribution on smaller RRs
Armand,

WWII PRR - the Broad Way - select portions of the 4 track main between
Harrisburg and Pittsburgh.

What road is your data for?

I'm collecting data to help "balance" a fleet currently being
collected, plus make sure I design enough of, and the right kind of,
staging.

I have what some view as over-ambitious plans (and some don't), but
need to build the space first - large plans on standby waiting to see
where the economy trends long term, and my projected long-term income
to pay for it. Confidence level way down from two years ago. I do not
want to go broke, but I also do not want to regret being too small
with money in the bank and too late/too messy to add-on again.

For now I help build and operate other layouts in the area. I'm almost
20 years from retirement, so space and layout construction is wait and
see - layout design, fleet analysis and collecting the fleet are
on-going. Regret not buying the right cars 5-10 years ago that are now
hard to find.

I concur with your concept of higher than "national fleet average" for
interchange roads - I took a quick look at the Southern Railway
conductor data out of Potomac yard (in the files section) - seems to
me as if interchange roads (e.g. PRR) are appearing at a higher than
national rate.

And this makes sense - if home road cars are higher than the national
rate on the home road, how can they magically change to national
percentages at interchange roads (a mathematical discontinuity - which
is not natural). Captive service can explain some of the
discontinuity, but not all. Plus if the road has excess MTs (as the
PRR did on the east end during WWII due to the large Europe bound
traffic imbalance), then I would expect eastern road MTs to be quickly
sent home to avoid per-diem (e.g. let the NYC find loads for their
cars - and they probably had a bigger surplus of MTs than the PRR
because I do not think the NYC generated anywhere near the same volume
of loads on their east end compared to the PRR east end). Both PRR and
more distant MT cars (e.g. ATSF, UP, SP, etc) would be loaded first to
either gain more revenue, or so the per-diem could be avoided for cars
that may take days to move off the system, respectively. Because the
PRR would load as many of their cars as possible, many of them would
hit interchange roads in higher than the national percentage rates
(and vice-versa).

So I'm generally headed towards national average, plus much higher
PRR, plus a little bit higher than national percentages for
interchange roads (especially small roads mostly within PRR's
territory). Note that all of this discussion is for box cars.

My very limited review of available pix seems to back this up, but
more data would be helpful. But I've read enough to convince myself
that my projected balance is plausable, and not so far outside the
expected that others would take issue with it when visiting, unless
they generated their own wheel reports, dumped it into Excel, and
compared it to the ORER data.

But I have just convinced myself that a number of the cars I now have
will need to be fiddled just so the rare cars do not appear too often
individually (e.g. that Ann Arbor OB box car), or the rare cars in
total are not too high of a precentage of a train's consist (e.g
should not have an SP&S, WM, Ma&Pa, LS&I, AA, CofG, MEC, and FEC in a
train with 20 boxcars - in any train with 20 boxcars only one of these
cars should appear on a very irregular basis - nearly all will need to
be from the top 30 roads). This may be less interesting and less
exciting (not spotting a rare car/road every 5 minutes), but would be
much more prototypical.

One of my main objectives is for operators to experience what would be
as close as possible to a typical WWII PRR day at work (within the
very significant constraints of scale modeling in a very limited
space). I want crew encounters of the rare car to be... rare. If I can
afford the space and layout I hope to build, then hopefully visitors
will be impressed by the shear magnitude of WWII PRR 4-track
operations (traffic volumes and densities). My grandfather worked for
the PRR during that period (57 years total - I bleed Tuscan) and was
justifiably proud. I want to capture that. I do not want operators
walking out the door marveling at all of the odd cars they saw in one
afternoon.

Regards,
Dave Evans

Re: Freight Car Distribution on smaller RRs

Ray Breyer
 

Anthony Thompson wrote:
Mike Brock does a bit less analysis than Dave Evans, then writes:
Let's see...when 9847 box cars have made an appearance, I can
have an MWR box car show up. That means about every 100 op
sessions. Hmmm. Anyone need an MWR box car?
I think you've grasped the essential point, Mike <g>.
And the point flies completely out the window if you model the MWR as an online shipper, for any one of the three railroads that connected with them in central Indiana. The same applies to other "novelty" shippers like the C&IM, MRS, or anyone else with a fleet of semi-captive service boxcars, thus completely screwing up the Gilbert-Nelson model.
 
Essentially, the G-S hypothesis is a useful STARTING POINT for assembling a boxcar fleet. But there are far too many "fudge factor fixes" in it to make it a true theory. Direct connections, home road car numbers, captive service fleets, moody yardmasters, picky customers, goofy routings, and various types of specialty loading racks, not to mention the ever popular "100 railroads with .1% of the fleet: pick one to model, any one!" tend to make any real car counting exercise just a fun numbers game.
 
Ray Breyer
Lies, damned lies, and statistics
 
(The MWR is a semi-online shipper on my layout: I need at least six cars in a 350 box fleet. There's a model RR that's about to get underway in CA that'll need their entire roster, since that NKP mainline goes right through Muncie)









[Non-text portions of this message have been removed]

Re: The third hand

Jack Burgess
 

Hey Jack,

Maybe these small smooth jaw alligator clamps would work for you.
Go to this
link and look at the picture on part #34, about half way down the page:

<http://www.electronicplus.com/content/ProductPage.asp?maincat=wa&
subcat=wal
That might work well Joe...the teeth on regular alligator clips don't
"match" each other, making them worthless for small items.

Jack Burgess
www.yosemitevalleyrr.com

Re: The third hand

Joseph Melhorn
 

Hey Jack,

Maybe these small smooth jaw alligator clamps would work for you. Go to this
link and look at the picture on part #34, about half way down the page:

<http://www.electronicplus.com/content/ProductPage.asp?maincat=wa&subcat=wal
I have used these to hold small parts, wires, etc., for gluing or soldering.
I replaced the alligator clips with these on a set of third hands that I
picked up at Harbor Freight. At one time, Radio Shack carried them, I don't
know if they still do.

Joe Melhorn
Orangevale, CA

I would like to modify my Xacto Third Hand...the alligator clamps are
worthless with small parts. They need to be replaced with spring clamps with
parallel jaws but I haven't found something like that...I want to be able to
hold things like .008" wire, etc.

Re: Freight Car Distribution on smaller RRs

Mike Brock <brockm@...>
 

Tony Thompson writes:

"I think you've grasped the essential point, Mike <g>."

Perhaps. But two issues stand out.

One, I don't believe box car distribution is random. The data doesn't seem to support it...although box car appearances may well be random along with a fudge factor...what one might call the Coefficient of Association...to be used in some cases [ UP/SP, for exampler ] to alter a random distribution.

Two, in many cases we modelers model frt trains...not frt fleets. IOW, there are known train examples...the infamous UP frt train with fully 50% of its cars being SP box cars, tank car trains, lumber trains, UP trains consisting entirely of box cars with no UP box cars in the consist, etc. In order to model them, we likely find ourselves with frt car fleets that don't match that which MIGHT reflect the total frt cars active in a given long term time span. For sure, train consists tell us that frt train populations are definitely NOT random draws from a frt car fleet that might appear over a long period. Instead, frt trains seem to be populated according to the train's function which...at least on the UP in Wyoming...were unique in our time period.

I might have a photo of a UP frt train with a Lackawanna hopper car on Sherman Hill [ I do ] and I might like to model it. One must, however, be aware that that &*^%*& Lackawanna hopper didn't show up every day....except in my case for which, of course, somewhat like Phil, the weatherman in Pittsburgh, every day is May 14, 1954.

Mike Brock

Re: Freight Car Distribution on smaller RRs

George Courtney
 

For pure entertainment's sake, wouldn't research into the Ball
Glass records of where their customers were located give a clue as to
where such boxcars would appear?

Where would Ball Glass jars be shipped? To food processors and/or
wholesale grocers? I think of their market as home canning with the
jars bought by consumers where? Or was the glass jar market
elsewhere?

George Courtney






- In STMFC@..., Anthony Thompson <thompson@...> wrote:

Mike Brock does a bit less analysis than Dave Evans, then writes:
Let's see...when 9847 box cars have made an appearance, I can
have an
MWR box car show up. That means about every 100 op sessions. Hmmm.
Anyone need an MWR box car?

Re: Freight Car Distribution on smaller RRs

Jack Burgess
 

John asked:

Do you have any data showing which cars arrived loaded and which were
supplied by ATSF or SP for lumber loading?
Not by ownership. Incoming box car loads, other than LCL, included shipping
bags for cement, lead baryte, and jasper; some mining supplies; and
55-gallon drums of diesel (for a standard gauge railroad quarry operation
accessible only by incline). Outgoing loads included bagged lead baryte
(drilling mud), bagged cement, bagged jasper, and finished lumber products.
In August 1930, the National Lead shipped out the following 21 loaded cars
via these cars and to these destinations:

SP 14723 Goleta CA
SP 49026 Modesto CA
SP 41288 Modesto CA
SP 40263 Modesto CA
SP 23433 Olig CA (I don't know where that was)
ATSF 126378 Hobbs NM
ATSF 128533 Hobbs NM
SP 21087 Hobbs NM
SP 23054 Hobbs NM
ATSF 125210 Hobbs NM
ATSF 123019 Hobbs NM
T&NO 54056 Hobbs NM
SP 24207 Hobbs NM
SP 27401 Hobbs NM
SP 28532 Hobbs NM
ATSF 127713 Los Angeles CA
ATSF 128185 Los Angeles CA
ATSF 130312 Los Angeles CA
MC 98521 Los Angeles CA
SP 18398 Bakersfield CA
SP 125846 Bakersfield CA

A total of 13 out of 21 of these cars were SP or T&NO cars or 62%..

As far as loads from the lumber mill, I don't have car ownership but I do
have shipping records for August 1939, the month/year that I am modeling.
The YV handled 123 loaded box cars of lumber that month. Of those, 78% were
shipped out via the SP interchange and 22% via the ATSF interchange. Of the
SP loads, 57% were shipped out of state while 43% of the loads were shipped
within California. The loads for the ATSF were 70%/30%.

When added to the empty cars on hand data, it "seems" that the SP was
providing most of the cars and were definitely getting most of the loads. I
doubt that this was accidental or due to the clerks getting a bottle of
whiskey at Christmas (nor did the SP own a portion of the YV). The YV and SP
had a long relationship....long distance Pullmans (and some from LA) on the
SP were handed over to the YV to be taken to Yosemite. When the YV needed a
diner each summer, they leased it from the SP. When the YV needed some extra
engines, they got them from the SP. After a severe flood in late 1937 wiped
out miles of YV roadbed, it was the SP that provided a loan to quickly
repair the line...the SP needed that connection to Yosemite restored before
the beginning of the 1938 summer tourist season. So, regardless of
percentages of freight cars and other things, the YV was a good source of
revenue to the SP and working closely with the SP allowed the YV to
reciprocate for SP's support.

Tony....Is that an argument which might support the idea of "proximity
interchange"?

Jack Burgess
www.yosemitevalleyrr.com

Re: Freight Car Distribution on smaller RRs

Anthony Thompson <thompson@...>
 

Mike Brock does a bit less analysis than Dave Evans, then writes:
Let's see...when 9847 box cars have made an appearance, I can have an MWR box car show up. That means about every 100 op sessions. Hmmm.
Anyone need an MWR box car?
I think you've grasped the essential point, Mike <g>.

Tony Thompson Editor, Signature Press, Berkeley, CA
2906 Forest Ave., Berkeley, CA 94705 www.signaturepress.com
(510) 540-6538; fax, (510) 540-1937; e-mail, thompson@...
Publishers of books on railroad history

Re: Freight Car Distribution on smaller RRs

Anthony Thompson <thompson@...>
 

Dave Evans wrote (in small part):
A) This helps justify having a significant collection of rare cars, as long as there is a large fleet of "core cars" that can be quickly accumulated and put in operating order (e.g. shake the box).
b) Fiddling may be a lot more necessary than originally thought, if "appearances" are to match the "Nelson-Gilbert" model.
Very thoughtful discussion, Dave, and I appreciate the thrust of your analysis--and I think it's a sensible way to demonstrate one way the Gilbert-Nelson idea can be expressed in practice. I've saved your message in my "layout thoughts" folder for future reference.

Tony Thompson Editor, Signature Press, Berkeley, CA
2906 Forest Ave., Berkeley, CA 94705 www.signaturepress.com
(510) 540-6538; fax, (510) 540-1937; e-mail, thompson@...
Publishers of books on railroad history

Re: Freight Car Distribution on smaller RRs

Mike Brock <brockm@...>
 

Richard Hendrickson says:

"Fact #2: The
1940 Car Builders' Cyclopedia shows a total of 738,509 box cars in
service on the North American railroads in 1/39. That means that out
of 9,847 box cars, one was an MWR car. And y'all think that one car
had even the most remote likelihood of turning up on the Yosemite
Valley RR?"

Well...Hmmm. On UP in Wyoming, we know that during March 1949, the 35 frt trains in Fraley's book moved about 75.7 cars per train [ did I count them? Of course not ]. Of these, about 30 cars per train were box cars [ all those reefers mess up the data ]. So...in a given day [ coincidentally, the Wyoming Div saw about 35 frt trains per day ], about 1050 box cars moved across Wyoming. The odds of an MWR making an appearance randomly are 1 in 9847. In 10 days, UP would have seen 10500 cars so, if random, one MWR car would appear in Wyoming. OTOH, the appearance of the MWR car...or the others for that matter...might not be random. That would be nice because, in that case we could forget all this nonsense [ hmmm ]. Anyhow, if random, every 10 days, one MW car will appear. Wow! Great! Hmmm. There IS one tiny problem. Of the 738,509 box cars, 18,588 are MP cars [ using the 1953 ORER data ]. Thus, every 40 box cars there will be one MP box car...or in 10500 cars, 262 MP box cars will appear. Worse, every 24 box cars will be one SP box car. In 10 days I should see 437 SP box cars....or 44 SP box cars per day. Hmmm. About 900 Pennsy box cars will make an appearance in 10 days...90 per day....2.6 per train. Of course, I only run 8 frt trains in a given op session and I compress them by about 60%. Thus, I will need 1.6 Pennsy box cars per train...or 12.5 Pennsy box cars in 8 trains. My frt trains will average about 30 cars and about 12 box cars. These 8 frt trains will move 96 box cars per session. Let's see...when 9847 box cars have made an appearance, I can have an MWR box car show up. That means about every 100 op sessions. Hmmm.

Anyone need an MWR box car?

Mike Brock

Re: Freight Car Distribution on smaller RRs

Anthony Thompson <thompson@...>
 

Richard Hendrickson wrote:
Fortunately, Jack Burgess has a stronger grasp of reality than numerous others on this list and is sensible enough not to run a model of a MWR box car on his YV layout and then have to explain and rationalize it to every halfway knowledgeable person who comes in the door and raises an eyebrow when they see it. In addition to accuracy, one objective of prototype modeling is plausibility. If something is implausible, don't do it.
This is an important point and of course goes far beyond freight car distribution. But I'd modify Richard's advice to say that if you are doing something in your modeling which is, let's say, of limited plausibility but DOES conform to a prototype practice, you need to demonstrate same. I have a friend who put prototype photographs on his layout fascia for anything in a scene which might strike some as implausible.

Tony Thompson Editor, Signature Press, Berkeley, CA
2906 Forest Ave., Berkeley, CA 94705 www.signaturepress.com
(510) 540-6538; fax, (510) 540-1937; e-mail, thompson@...
Publishers of books on railroad history

Re: Freight Car Distribution on smaller RRs

Anthony Thompson <thompson@...>
 

Armand Premo wrote:
While the Nelson-Gilbert study is a valuable tool it does not apply in every instance. Regional carriers will get more traffic from railroads that either directly connect or are in close proximity. After carefully studying wheel reports for several years I must conclude that what I possess is a better indicator of what ran on the roads that I model.Company annual reports also support my findings.
Armand is lucky enough to have substantial documentation of freight traffic for his road--few of us are so lucky. But I don't think it, of itself, proves the "proximity interchange" argument. Other roads do not seem to obey that argument, so in Armand's case (as in a number of others), we see that each road can be different.

Tony Thompson Editor, Signature Press, Berkeley, CA
2906 Forest Ave., Berkeley, CA 94705 www.signaturepress.com
(510) 540-6538; fax, (510) 540-1937; e-mail, thompson@...
Publishers of books on railroad history

Re: Freight Car Distribution on smaller RRs

armprem
 

Dave,Which road do you model?Armand Premo

----- Original Message -----
From: "devansprr" <devans1@...>
To: <STMFC@...>
Sent: Wednesday, February 04, 2009 7:18 PM
Subject: [STMFC] Re: Freight Car Distribution on smaller RRs


--- In STMFC@..., "Mark Pierce" <marcoperforar@...> wrote:

While the odds of any particular small railroad's car (most likely a
box car) would be on another, far-away, small railroad's tracks is
probably too small to measure, I propose that the odds of any one of
all such small railroads' cars showing up is much higher. For us
model railroaders, I say have a small fleet of "oddball" rolling
stock but rotate them on/off the layout.

Mark Pierce

--- In STMFC@..., Bruce Smith <smithbf@> wrote:

Folks can argue whether the Nelson-Gilbert model is valid or
not 'til
they are blue in the face, but one advantage we, as WWII era
modelers
have, is that the Nelson-Gilbert model is the RULE... since the
car
service rules were suspended. What that does for you in this
situation is unclear, since the M&W proportion of the national
pool
is pretty small...say for the purposes of discussion, 0.1% In
that
case one M&W car would visit the YV for every 1000 foreign boxcars
that visit. Not impossible, but definitely unlikely. Normally, I
think most of us say "don't model the oddballs", but in this case,
this is a "teachable moment". The presence of occasional rare-
road
boxcars represents the REALITY of the WWII traffic pattern, and is
part of what is "normal" for that period of time. I have reserved
a
small percentage of my fleet for "interesting" rare foreign cars
for
precisely that reason.
Actually, there are many reporting remarks well under 0.1%. In fact an
analysis of the 1943 ORER type X and XM shows that the 100 smallest
box car fleets (per reporting mark) had a total of approximately 1860
X and XM cars - which was 0.2% of the national fleet - which would
equate to only one of those reporting marks in a 500 box car fleet.

In 1943:

The top 11 roads had 50% of the fleet. Sorry Mike, but NP placed 14th,
with 2.6% of the national fleet. But any WWII layout with at least 40
box cars needs one NP box.

For some idea of the "random" car, in addition to the 100 smallest
fleets, another 50 roads had less than 0.1% of the fleet - so Ann
Arbor (the biggest fleet of the 50), would be one out of every 1000
box car appearances on a layout.

Rather than think in terms of someone's fleet, another way to look at
it would be the number of cars routed out of staging each session.

So for a layout that moves 200 X and XM cars out of staging per op
session the Ann Arbor car would appear once every 5 sessions.

With the largest fleet, 22 PRR X and XM's would need to be moved on
scene each session. Five NP boxcars out of staging would be
appropriate per session.

But for the 100 smallest fleets, only one car, picked from a
collection of these railroad's box cars, would appear every 4th
session. None of the cars from this "smallest" road pool would appear
3 out of 4 sessions.

Another way to look at this is that 39 road's box cars would "earn" an
appearance every session, totaling 178 of the 200 boxcars appearing
per session. (Katy is the last "regular" on the list)

It would then be appropriate for the final 22 cars used during the
session to be drawn from a fleet of "occasional" cars that would not
be used every session.

18 more roads would earn an appearance at least every other session
(including well known roads such as T&P, Cotton Belt, D&H, WM & WP.)
These roads would constitute about 14 cars per session.

About 40 roads could be used for 7 more of the 200 cars - some
appearing once every 3rd session (KCS), and a few only every 20th
session (e.g. NWP).

One car per session could be drawn from a pool of 117 reporting marks.

For a volume of 200 cars on-scene per session, and assuming that after
5 sessions all of the operators have forgotten when they last saw the
rare, small road X/XM, then I would need a fleet of 178 cars to appear
every session (from 39 roads), another 33 or more cars to appear one
to four times per 5 sessions (from 33 roads), and anywhere from 25 to
147 cars with 147 different reporting marks that would appear only
once per five sessions (it would be appropriate for 5 different cars
from this pool to appear each session). Note that popular roads such
as Rutland, Clinchfield, Georgia, SP&S, DM&IR, TH&B fall into this
"once per five session" pool!

Minimum fleet would be 236 cars - upon entering staging, 89% of the
cars entering staging would go right back out, but the other 11% would
need to be "fiddled" between sessions.

This analysis is obviously very hypothetical, but it leads to a few
conclusions for a layout that moves 200 boxcars out of staging each
session:

1) Small road cars can appear in medium size fleets, but about 11% of
the fleet may need to be fiddled between sessions (into or out of
storage).

2) For an out-of-staging traffic level of 200 cars per op session, an
additional 18% of the fleet would be required to model the "rare"
cars, assuming that everyone forgets what they saw more than 5 op
sessions ago (this pool gets larger as everyone's memory gets longer).

3) Half the cars that appear each session would come from just 11
roads. While this might seem boring, it might actually enhance the
railfanning aspect of trying to spot the rare cars - diamonds in the
rough so to speak.

Personnal lessons learned:

A)This helps justify having a significant collection of rare cars, as
long as there is a large fleet of "core cars" that can be quickly
accumulated and put in operating order (e.g. shake the box).

b) Fiddling may be a lot more necessary than originally thought, if
"appearances" are to match the "Nelson-Gilbert" model. This has a
significant impact on staging design, and tends against the "put
staging under the layout" concept. At these traffic levels, for each
train entering staging, 1 in 10 X/XM's will need to be changed out.

c) To implement the Nelson-Gilbert distribution model, a lot more car
storage will be required at the fiddle location - enough space for at
least 40-50 boxcars.

One other quick Calculation (still based on operator memories only
lasting five sessions):

For a smaller layout with 50 X/XM's entering from staging per session,

- 17 roads appear every session = 34 cars (includes one NP boxcar for
Mike)

- 27 roads (and at least 27 cars) that appear at least once every 5
sessions. 12 cars each session from this pool.

- A pool of at least 20 cars, where each car will appear not more than
once every 5 sessions, with 4 cars from this pool appearing each
session. Note that this pool includes roads such as CGW, Cotton Belt,
D&H, MEC, B&M, WM, WP, KCS, CofG - so these are not "rare" roads.

- For the smaller fleet, 1 out of 3 of the boxcars will need to be
"fiddled" into and out of storage every session. Fiddle storage is
still in the 40-50 car range.

At the other extreme (not sure if anyone operates this big), for 1000
X/Xm's entering from staging each session:

- 70 roads' boxcars are present every session = 976 cars that appear
every session and do not need to be fiddled. 500 of these cars will
come from only 11 roads! (kind of boring, and kind of prototypical...)

- 31 roads (and at least 31 cars) that appear at least once every 5
sessions. 17 cars from this pool appear each session. This pool still
includes roads such as Ann Arbor, Rutland, Clinchfield, DM&IR, SP&S.

- A pool of at least 35 cars, from 119 reporting marks, with 7 cars
appearing from this pool every op session. Each car should only appear
once per five sessions. Notable infrequent roads in this pool for such
a huge layout include: Ma&Pa, LS&I, FEC (does not include ventilated
boxcars), and Virginian.

- For the huge fleet, only 2.4% of the fleet will need to be fiddled
each session. This is likely less than one boxcar per train to fiddle.
Interesting that this is almost exactly the same number of boxcars
fiddled for the 200 boxcar session. Only need around 60-70 cars of
storage at the fiddle yard (minimum).

It is intersting that while the small layout session requires a lot of
fiddling, one can justify in-frequent appearances of a much larger
percentage of the cars - it just happens that most of these
"infrequent" cars should be for pretty large railroads, unless your
operator's memories are short;-)

At the other extreme, for large layouts the major roads rule -
prototypical but not very interesting. This would add a "look out for
the odd car" concept to the op session much like railfanning the
prototype that might be enjoyed a little - "Hey, did you spot that
SP&S boxcar last session?"

Enough rambling..

Dave Evans

PS - I promise not to do this again - but I needed a long break from
some very tedious work. Sorry...



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Re: Freight Car Distribution on smaller RRs

devansprr
 

--- In STMFC@..., "Mark Pierce" <marcoperforar@...> wrote:

While the odds of any particular small railroad's car (most likely a
box car) would be on another, far-away, small railroad's tracks is
probably too small to measure, I propose that the odds of any one of
all such small railroads' cars showing up is much higher. For us
model railroaders, I say have a small fleet of "oddball" rolling
stock but rotate them on/off the layout.

Mark Pierce

--- In STMFC@..., Bruce Smith <smithbf@> wrote:

Folks can argue whether the Nelson-Gilbert model is valid or
not 'til
they are blue in the face, but one advantage we, as WWII era
modelers
have, is that the Nelson-Gilbert model is the RULE... since the
car
service rules were suspended. What that does for you in this
situation is unclear, since the M&W proportion of the national
pool
is pretty small...say for the purposes of discussion, 0.1% In
that
case one M&W car would visit the YV for every 1000 foreign boxcars
that visit. Not impossible, but definitely unlikely. Normally, I
think most of us say "don't model the oddballs", but in this case,
this is a "teachable moment". The presence of occasional rare-
road
boxcars represents the REALITY of the WWII traffic pattern, and is
part of what is "normal" for that period of time. I have reserved
a
small percentage of my fleet for "interesting" rare foreign cars
for
precisely that reason.
Actually, there are many reporting remarks well under 0.1%. In fact an
analysis of the 1943 ORER type X and XM shows that the 100 smallest
box car fleets (per reporting mark) had a total of approximately 1860
X and XM cars - which was 0.2% of the national fleet - which would
equate to only one of those reporting marks in a 500 box car fleet.

In 1943:

The top 11 roads had 50% of the fleet. Sorry Mike, but NP placed 14th,
with 2.6% of the national fleet. But any WWII layout with at least 40
box cars needs one NP box.

For some idea of the "random" car, in addition to the 100 smallest
fleets, another 50 roads had less than 0.1% of the fleet - so Ann
Arbor (the biggest fleet of the 50), would be one out of every 1000
box car appearances on a layout.

Rather than think in terms of someone's fleet, another way to look at
it would be the number of cars routed out of staging each session.

So for a layout that moves 200 X and XM cars out of staging per op
session the Ann Arbor car would appear once every 5 sessions.

With the largest fleet, 22 PRR X and XM's would need to be moved on
scene each session. Five NP boxcars out of staging would be
appropriate per session.

But for the 100 smallest fleets, only one car, picked from a
collection of these railroad's box cars, would appear every 4th
session. None of the cars from this "smallest" road pool would appear
3 out of 4 sessions.

Another way to look at this is that 39 road's box cars would "earn" an
appearance every session, totaling 178 of the 200 boxcars appearing
per session. (Katy is the last "regular" on the list)

It would then be appropriate for the final 22 cars used during the
session to be drawn from a fleet of "occasional" cars that would not
be used every session.

18 more roads would earn an appearance at least every other session
(including well known roads such as T&P, Cotton Belt, D&H, WM & WP.)
These roads would constitute about 14 cars per session.

About 40 roads could be used for 7 more of the 200 cars - some
appearing once every 3rd session (KCS), and a few only every 20th
session (e.g. NWP).

One car per session could be drawn from a pool of 117 reporting marks.

For a volume of 200 cars on-scene per session, and assuming that after
5 sessions all of the operators have forgotten when they last saw the
rare, small road X/XM, then I would need a fleet of 178 cars to appear
every session (from 39 roads), another 33 or more cars to appear one
to four times per 5 sessions (from 33 roads), and anywhere from 25 to
147 cars with 147 different reporting marks that would appear only
once per five sessions (it would be appropriate for 5 different cars
from this pool to appear each session). Note that popular roads such
as Rutland, Clinchfield, Georgia, SP&S, DM&IR, TH&B fall into this
"once per five session" pool!

Minimum fleet would be 236 cars - upon entering staging, 89% of the
cars entering staging would go right back out, but the other 11% would
need to be "fiddled" between sessions.

This analysis is obviously very hypothetical, but it leads to a few
conclusions for a layout that moves 200 boxcars out of staging each
session:

1) Small road cars can appear in medium size fleets, but about 11% of
the fleet may need to be fiddled between sessions (into or out of
storage).

2) For an out-of-staging traffic level of 200 cars per op session, an
additional 18% of the fleet would be required to model the "rare"
cars, assuming that everyone forgets what they saw more than 5 op
sessions ago (this pool gets larger as everyone's memory gets longer).

3) Half the cars that appear each session would come from just 11
roads. While this might seem boring, it might actually enhance the
railfanning aspect of trying to spot the rare cars - diamonds in the
rough so to speak.

Personnal lessons learned:

A)This helps justify having a significant collection of rare cars, as
long as there is a large fleet of "core cars" that can be quickly
accumulated and put in operating order (e.g. shake the box).

b) Fiddling may be a lot more necessary than originally thought, if
"appearances" are to match the "Nelson-Gilbert" model. This has a
significant impact on staging design, and tends against the "put
staging under the layout" concept. At these traffic levels, for each
train entering staging, 1 in 10 X/XM's will need to be changed out.

c) To implement the Nelson-Gilbert distribution model, a lot more car
storage will be required at the fiddle location - enough space for at
least 40-50 boxcars.

One other quick Calculation (still based on operator memories only
lasting five sessions):

For a smaller layout with 50 X/XM's entering from staging per session,

- 17 roads appear every session = 34 cars (includes one NP boxcar for
Mike)

- 27 roads (and at least 27 cars) that appear at least once every 5
sessions. 12 cars each session from this pool.

- A pool of at least 20 cars, where each car will appear not more than
once every 5 sessions, with 4 cars from this pool appearing each
session. Note that this pool includes roads such as CGW, Cotton Belt,
D&H, MEC, B&M, WM, WP, KCS, CofG - so these are not "rare" roads.

- For the smaller fleet, 1 out of 3 of the boxcars will need to be
"fiddled" into and out of storage every session. Fiddle storage is
still in the 40-50 car range.

At the other extreme (not sure if anyone operates this big), for 1000
X/Xm's entering from staging each session:

- 70 roads' boxcars are present every session = 976 cars that appear
every session and do not need to be fiddled. 500 of these cars will
come from only 11 roads! (kind of boring, and kind of prototypical...)

- 31 roads (and at least 31 cars) that appear at least once every 5
sessions. 17 cars from this pool appear each session. This pool still
includes roads such as Ann Arbor, Rutland, Clinchfield, DM&IR, SP&S.

- A pool of at least 35 cars, from 119 reporting marks, with 7 cars
appearing from this pool every op session. Each car should only appear
once per five sessions. Notable infrequent roads in this pool for such
a huge layout include: Ma&Pa, LS&I, FEC (does not include ventilated
boxcars), and Virginian.

- For the huge fleet, only 2.4% of the fleet will need to be fiddled
each session. This is likely less than one boxcar per train to fiddle.
Interesting that this is almost exactly the same number of boxcars
fiddled for the 200 boxcar session. Only need around 60-70 cars of
storage at the fiddle yard (minimum).

It is intersting that while the small layout session requires a lot of
fiddling, one can justify in-frequent appearances of a much larger
percentage of the cars - it just happens that most of these
"infrequent" cars should be for pretty large railroads, unless your
operator's memories are short;-)

At the other extreme, for large layouts the major roads rule -
prototypical but not very interesting. This would add a "look out for
the odd car" concept to the op session much like railfanning the
prototype that might be enjoyed a little - "Hey, did you spot that
SP&S boxcar last session?"

Enough rambling..

Dave Evans

PS - I promise not to do this again - but I needed a long break from
some very tedious work. Sorry...

Re: Freight Car Distribution on smaller RRs

Richard Hendrickson
 

On Feb 4, 2009, at 12:49 PM, Tim O'Connor wrote:
.... even the "G-B Theory" would predict an extremely low
PROBABILITY of a Muncie & Western box car appearing on the YV in 1939!
So it's no surprise that you can't find one in such a small sample. If
you had a sample of several thousand cars, I'd be very surprised if
there was no M&W box car.







Oh, come on, guys, get real. I've fast forwarded through most of
this discussion as being a tiresome rehash of the same old arguments
about car distribution, but instead of this endless speculation, how
about considering some facts, starting with fact #1: the 10/38 ORER
shows exactly 75 box cars under MWR reporting marks. Fact #2: The
1940 Car Builders' Cyclopedia shows a total of 738,509 box cars in
service on the North American railroads in 1/39. That means that out
of 9,847 box cars, one was an MWR car. And y'all think that one car
had even the most remote likelihood of turning up on the Yosemite
Valley RR? Yes, theoretically its possible; it could have happened,
even though the odds against it are astronomical. It's also
theoretically possible that the planet Jupiter is made of green
cheese (we can't say that any more about the moon or Mars, because
we've been there so we have concrete evidence of their composition).
Fortunately, Jack Burgess has a stronger grasp of reality than
numerous others on this list and is sensible enough not to run a
model of a MWR box car on his YV layout and then have to explain and
rationalize it to every halfway knowledgeable person who comes in the
door and raises an eyebrow when they see it. In addition to
accuracy, one objective of prototype modeling is plausibility. If
something is implausible, don't do it. Even if you have evidence
that it actually happened, it will destroy for your viewers what 19th
century poet/critic Samuel Taylor Coleridge aptly called "the willing
suspension of disbelief." That suspension of disbelief is what makes
it possible to plausibly recreate history in 1:87 (or whatever other)
scale. If you're going to do things that are highly implausible
because they're interesting or "cute," you might as well go back to
running Lionel around the Christmas tree.

Richard Hendrickson

Re: The third hand

peteraue
 

--- In STMFC@..., "Manfred Lorenz" <germanfred55@...> wrote:

--- In STMFC@..., "peteraue" <peteraue@> wrote:
I built a number of resin kit boxcars and found a properly sized
wood
block and a few rubber bands almost ideal. The thickness of the wood
block exactly matches the inside width of the boxcar and it must be
3/8" or so shorter than the inside length of the car. I attach both
car sides and the car floor to the block (with rubber bands)and glue
the floor to the sides. If sides and floor do not line up
perfectly, I
sand them flush with the wood block in place. Thereafter I attach
the
ends (more rubber bands)such that there are gaps between the ends of
the block and the car ends. I line it all up, run ACC down on the
inside of all four corners and bingo - I have a perfectly square
carbody. I leave the wood block inside the carbody for detailing the
underframe until I must take it out for attaching the roof.
Thanks for sharing your technique. That sounds straight forward and
simple. What bothers me is the sanding part. Albeit easy enough.

I have to do without the clamp. Reading your way of doing it it
appears to me to try using super magnets semi-permanently tacked to
the outer surface of the car sides and ends and position them on a
block of iron replacing the rubber bands. What it still needs is also
a perfectly parallel inner surface of each part.

Hmm, thinking while writing: How abouts three (3) screws through the
block that adjust the part to parallel with the block from below? The
holes are sunken into the block so they don't obstruct the opposit
side they try to adjust. The magnets should perhaps be strong enough
to overcome the small distances involved to compensate for any back
side irregularities. Or the screws have a moveable plate on their
tips like a clamp which is large enough to give the magnets a partner
to grip without being too precisely positioned?

Maybe some bluetack could replace the magnets? Then the block has to
be smaller than the width of the car to allow for the modelling clay.

Maybe a product idea?

Manfred
Manfred,

My wood block approach only works if the wood has a smooth surface and
the thickness of the block matches the inside width of the car very
well. Different width cars require different size blocks. For me that
is not a problem. I have access to a thickness planer which permits
dimensional tolerances of approximately +/- .1mm. I found car sides
have extremely small variations in thickness so I see no need for
anything adjustable.
Peter Aue

N_G data was Re: Re: Freight Car Distribution on smaller RRs

SUVCWORR@...
 

Is the Nelson-Gilbert data in the group files? If so, I could not identify
it or don't know what I am looking for. If not where might it be located?

TIA

Rich Orr

**************Stay up to date on the latest news - from sports scores to
stocks and so much more. (http://aol.com?ncid=emlcntaolcom00000022)

Re: PRR FM40 - Sunshine vs F&C Decals for circa 1942?

Bruce Smith
 

On Feb 4, 2009, at 2:45 PM, parkcitybranch wrote:

I need some decals to letter a few PRR FM40 flat cars. I looked at
the decals available from Sunshine and they are described as "late
steam era". What exactly does that mean? I want to model the cars
circa 1942, will the Sunshine decals let me do that or should I use
the F&C decals? I am concerned about some of the F&C decals because
of the comments in the archives but I am not sure if those comments
apply to the PRR FM40 decals. Thanks.

Jason Sanford
Jason,

There is no "FM40" class of PRR flat car. Since you refer to both sunshine and F&C, I'm going with class "FM", which was a 40' car (is that what the 40 is?). The Sunshine decals are definitely better quality than the F&C. As listed by Sunshine, the kit is simply PRR Revenue service and few if any of these cars had anything other than their WWII era paint applied. I have not actually looked at these decals lately, having built my Sunshine FMs for MOW service, but you might also consider Champ set HC-97. In all likelihood, to get accurate lettering you will need to mix and match a variety of decals.

Regards
Bruce

Bruce F. Smith
Auburn, AL
http://www.vetmed.auburn.edu/index.pl/bruce_f._smith2

"Some days you are the bug, some days you are the windshield."
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