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Re: A Purpose For Frt Car Distribution Studies

Malcolm Laughlin <mlaughlinnyc@...>
 

Posted by: "Gene Green" bierglaeser@... bierglaeser Sun Aug 17, 2008 8:07 am (PDT) --- In STMFC@yahoogroups. com, Anthony Thompson <thompson@.. .> wrote:

An average always means the same thing, Malcolm, though in a skewed distribution it will not lie at the same location as the most frequent data, which lay persons usually assume the average to be (and which it is in a symmetrical distribution) . But I have no idea what a "true average" is.
I'm well aware of the mean-mode-median thing, but to me "average" has always meant the sum of the observations divided by the count. But in the case of the distribution of freight cars 50 years ago, it really doesn't matter, we can't get enough data to make distinctions of that sort. I'd be amazed if anyone could find a good number for the percentage cars on-line by ownership for any day, week, month or year in the 50's or 60's. In the 50's the data couldn't have existed. If certain computer tapes on the Southern or NYC (and a very few others) from the mid-60's were still around we could do a count. There really was no reason for a railroad to do the count because it had no value for car management.

I'll repeat what I said yesterday about the value of an average number in this environment. Somoene said an average was a good start point. I agree in the sense that it's better than no number and beginning with an estimate of zero or infinity.

As for the percentage of cars by ownership on any one railroad, I think it's absurd to suggest that it might be the national average ownership.

I'm willing to wager that there was never a day when the distribution of cars across a railroad was ever within 20 percent of that average for more than 50 percent of the ownerships on line, excluding roads and ownerships too small for significance. Tim's calculation of that statistic, or just the fact that it can be calculated, does not make the result meaningful in the real world.

Taking a few consists (1000 is few in this context) and finding that they come close to the estimate is very shgaky statiatically. In many fields of research, using selected historical data to verify statistics is frowned upon because it is very subject to selection bias. That is when the researcher finds a correlation and announces it. But what really should be done is to make a good number if independent estimates using other data sets of the same kind to see if the results are reproducible. In this case that would require taking some number, like 10, other sets of unrelated consists on other railroads in different sections of the countryand comparing the results.



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

Re: Freight car distribution

gn3397 <heninger@...>
 

--- In STMFC@..., John Stokes <ggstokes@...> wrote:

Again, the best and perhaps only lesson is to try to avoid the "iconic" cars when they were
actually few in number, and balance your cars, with a good dose of home road cars,
depending on what the history of your prototype was at any given time, when they had or
didn't have a large fleet or kept it close to home, as in grain shipment time or on
dedicated mineral runs.

Reality is not the same as a computer simulation under the rather limited and primitive
conditions we are working in here.

It doesn't take a long time looking at photos, for example, of Northern Pacific or Great
Northern freight trains and yards to see that at least on the days the pictures were taken,
home road equipment often dominated, but the stats say otherwise. Go figure. Glad you
are having fun with all this, Mike.

John Stokes
Bellevue, WA
Mr. Stokes,
Actually, if you are modeling GN or NP immediately postwar, you will only want about
15-20% home road boxcars if you are modeling the grain rush in the fall. One of the more
fascinating ads that I found in my local paper's archive back in ND (which I stupidly didn't
copy) was a half page ad the GN placed in September 1946 explaining the lack of cars. If I
recall, the GN stated it only had about 3000 of its own boxcars online, of a fleet of approx
22,000 at the time. GN (and I am sure Soo and NP) were routinely excoriated by local
farmers and elevator operators because of a shortage of suitable boxcars for transporting
wheat to market.

I have corresponded with a couple of GN employees from this time period, one a
trainmaster, and one a rural station agent, and they both stated that car supply was a
constant headache. GN couldn't get its cars back online fast enough, despite putting out
warrants a few months ahead of time. The Eastern roads would also usually send their
worn out cars to the GN, which often were unsuitable for grain loading. Usually the linings
weren't grain tight, so loss in transit was an issue. GN maintained the linings of its cars
pretty well, because grain was the most important single commodity it carried. The
trainmaster I spoke to related the time he sent a solid 100 car train of mostly eastern
boxcars up a branch in eastern Montana, with rolls of heavy paper and coopering
materials supplied by the GN, and the next day 97 came back empty because they had
been refused by the local elevators!

I think another important point, which Mr. Gilbert repeatedly emphasized, was the state
of the US economy. All the 1930s era photos I have seen of GN stations and branches
show a preponderance (100% in some instances) of GN boxcars, no doubt because of the
poor economy lowering demand for cars, thereby allowing GN to keep its cars online.
Obviously, the situation was different postwar.

Anyway, this is an interesting discussion. I wish I had some conductors books or wheel
reports from some of the GN branches I am interested in to get a better feel for the car
distribution, but I have never come across any. I don't know that my layout will ever
accurately represent the actual percentages of boxcars that operated on the particular GN
branchline I am modeling, but I am shooting for 20% home road boxcars, and the other
80% will be distributed among the national percentages. If anyone ever finds data to
refute that, I would love to see it.

Sincerely,
Robert D. Heninger
Iowa City, IA

Re: A Purpose For Frt Car Distribution Studies

Rich <SUVCWORR@...>
 

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

Malcolm Laughlin wrote:
I'm OK with the average as the core datum, but recognizing that
the
average in the car distribution case may be at one side of a
skewed
distribution orm otherwise not a true average. Any average is
better
than zero or infinity as the starting point.
An average always means the same thing, Malcolm, though in
a
skewed distribution it will not lie at the same location as the
most
frequent data, which lay persons usually assume the average to be
(and
which it is in a symmetrical distribution). But I have no idea what
a
"true average" is.
It would appear that we are headed down the road of confusing average
and mean. Which are totally different. Given 10,000 freight cars
past a given point, the average will most likely mimic the national
fleet based on Tim and Dave's data. However, the mean may be skewed
in one direction or the other significantly.

Rich Orr

Rich Orr

Re: Freight car distribution

Mike Brock <brockm@...>
 

John Stokes writes:

"This is the other factor in this essentially impossible and largely meaningless exercise in trying to figure out how many cars of each type would typically be seen on a train in the time period selected and then extrapolate that information to one's model railroad. Who has 1000 + cars? Who has the full mix of car types within box car classes alone and who has a layout on which to run full length freight trains? Not very many of us at all."

Well...certainly not me. UP trains in my time period weere about 82 cars in length. Much of this was based on tonnage ratings. The line in question...between Laramie and Green River has...I believe...a max of 0.82 grade and UP generally liked to run relatively fast frt trains. Layout compression drops frt train lengths for me by at least 50%. 3 of 35 UP frt trains that we know of had 27-36 SP box cars in their consist. Assuming an 82 car length...I ain't gonna look it up...means the 3 trains had from 32% to 43% SP box cars. If I were to run a 40 car frt it could contain as many as 17 SP box cars. Well. Guess what. I don't have 17 SP box cars.

"Again, the best and perhaps only lesson is to try to avoid the "iconic" cars when they were actually few in number, and balance your cars, with a good dose of home road cars, depending on what the history of your prototype was at any given time, when they had or didn't have a large fleet or kept it close to home, as in grain shipment time or on dedicated mineral runs."

I agree. I will admit...as I have said...that it is sorta interesting to see a photo of cars where they "shouldn't be".

"Go figure. Glad you are having fun with all this, Mike."

Well, John, it's like this. Why else would I wade through this <G>.

Mike Brock

Re: diversions.

Malcolm Laughlin <mlaughlinnyc@...>
 

Posted by: "Bill McCoy" Diversions could be filed by the beneficial owner of the car's lading
as shown on the Bill of Lading and reflected on the Waybill that
accompanied the car. Up to 3 diversions could be made on a car IIRC.

============

Thanks for that input Bill. I'm glad to know there is someone on this list who saw the diversions at the working level. My input was from a more thoretical management level, but looks like we agree on the basic game/


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

A Purpose For Frt Car Distribution Studies. Was: Re: Re

Steve Lucas <stevelucas3@...>
 

Wrong phrase, from an admitted statistical neophyte. I should have
referred to the "law of large numbers".

http://en.wikipedia.org/wiki/Law_of_large_numbers

Steve Lucas.

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

Steve Lucas writes:

"Tony--

After reading this thread for some time, I have to agree with your
basic premise. Most major through transcon routes such as the UP in
Wyoming would very likely have over a given period, percentages of
each road's boxcars in keeping with the national averages. The law
of averages supports this."

Well...perhaps someone's law of averages supports it but the data
does not.
Can you explain that?

Mike Brock

Re: Freight car distribution

Tim O'Connor
 

Mike Brock wrote

My point exactly. The theory doesn't seem to apply to the
Overland Route for SP, CB&Q, C&NW, and Milw...
Actually, it applies exactly to the Overland Route. Your
samples are just too few to be statistically meaningful.
It's not even one day's worth of trains on the UP. The
data do not support ANYONE's theory. In the absence of
data, logic must prevail. Give me a logical explanation
for your consists, please! All you've said basically is
that Tim was wrong, based on a minute sliver of data. If
you have a better theory, I'm all ears.

Tim O'Connor

Re: Freight car distribution

Tim O'Connor
 

We've been down this road too -- most people take photos of
stuff they happen to like, or that catches their interest.
Almost no one took photos (and expended film) in order to
document "typical" stuff. Ergo: photos are not admissible
as evidence of anything other than what is depicted in them.

By the way, being an GN and NP fan, I've seen many photos
on each railroad where virtually no home road cars can be
seen. Including the infamous NP Montana branch line train
with a bunch of PRR empties headed to a grain elevator...

Tim O'

It doesn't take a long time looking at photos, for example, of Northern Pacific or Great Northern freight trains and yards to see that at least on the days the pictures were taken, home road equipment often dominated, but the stats say otherwise. Go figure. Glad you are having fun with all this, Mike.

John Stokes
Bellevue, WA

Re: Freight car distribution

Mike Brock <brockm@...>
 

Tim O'Connor writes:

"Mike, he ran 100,000 iterations of a 40 car box car train, composed
of cars chosen randomly from every possible prototype."

OK.

"The National
% is obvious,"

OK. 3.9% for SP in 1949.

"and then he finds the AVERAGE % found for that railroad
in the random consists. What is not obvious about this?"

Nothing. What's the value...IOW, so what?

I tallied the maximum number of cars for each railroad over all the
iterations. In a 40 boxcar train, the average number of cars would be
40 times the national percentage shown in the above table."
Why do you say that?
"Because he described it obscurely. He simply kept track of the largest
number of cars seen for each reporting mark in the 100,000 trains. Is
this not also obvious?

Well...actually that's not so at all. The correct number is 4. 136/34
If you use real...rather than theoretical data.
Real what? 136 box cars?"

Yep.

"Larry's example was PURELY theoretical, and he made an excellent point.
I guess some people just don't get it."

What's there to get?

We know that there were 4 of 34 trains...11.76%...of the trains with
far more than 9 SP bx cars.
Mike, you are having trouble grasping the idea. Larry has presented
100,00 theoretical trains, of fixed length, of random composition.
You persist with your miniscule sample of 34 actual trains of
varying length and composition of different sorts of cars (not just
box cars)."

Yep.

The 1953 data shows the "infamous" train with 36 or more SP box cars
[not T&NO ].
Yes, but I will argue that the Overland Route for the UP and SP was
a 'home road extension' in that each road was highly dependent on the
other for traffic. Therefore we can discount the presence of SP as
well as UP cars in all trains over Sherman Hill, for the purposes of
this discussion. This is exactly the "skew" that each layout has to
consider."

My point exactly. The theory doesn't seem to apply to the Overland Route for SP, CB&Q, C&NW, and Milw...although SP is the most significant violator. Other RRs might have similar situations...i.e, SP and SSW...ATSF and...well...ATSF. NP and GN with respect to CB&Q might also apply. Others might be MP and D&RGW and WP. The problem is, we don't have known data regarding those routes. However, the Overland Route should serve as a warning with regard to similar situations.

Mike Brock

Re: Freight car distribution

Stokes John
 

This is the other factor in this essentially impossible and largely meaningless exercise in trying to figure out how many cars of each type would typically be seen on a train in the time period selected and then extrapolate that information to one's model railroad. Who has 1000 + cars? Who has the full mix of car types within box car classes alone and who has a layout on which to run full length freight trains? Not very many of us at all. So the averages, which are a rule of thumb perhaps but otherwise are just a mental exercise, don't really apply to any actual person's layout. Far too many, many variables in a national system, with the almost infinite perambulations of individual railroads, prototype and model, for these figures to have real meaning to a modeler. Again, the best and perhaps only lesson is to try to avoid the "iconic" cars when they were actually few in number, and balance your cars, with a good dose of home road cars, depending on what the history of your prototype was at any given time, when they had or didn't have a large fleet or kept it close to home, as in grain shipment time or on dedicated mineral runs.

Reality is not the same as a computer simulation under the rather limited and primitive conditions we are working in here.

It doesn't take a long time looking at photos, for example, of Northern Pacific or Great Northern freight trains and yards to see that at least on the days the pictures were taken, home road equipment often dominated, but the stats say otherwise. Go figure. Glad you are having fun with all this, Mike.

John Stokes
Bellevue, WA



To: STMFC@...: brockm@...: Sun, 17 Aug 2008 20:18:51 -0400Subject: Re: [STMFC] Re: Freight car distribution




Tim O'Connor writes:"Good work, Larry! That's what I'm talkin' 'bout!A 40 car train with 9 SP (not counting T&NO) boxcars.."I assume you mean a train with 40 box cars. Actually the 1949 trains averaged 82.3 cars."More than 5 times the 'average' value of1.6."I'm not certain what the 1.6 represents. The actual number is 4.Mike Brock...I never thought statistics could be fun.

Re: Freight car distribution

Tim O'Connor
 

Mike Brock wrote

Larry, could you explain what you are talking about? You show RR [ i.e., SP
excluding T&NO ], number [ number of SP box cars { 27757 } ] Nat'l % [ you
show 4.0% but Tim shoed 3.9% ] and Random % [ 4.01% ]. What is the
derivation of the random %?
Mike, he ran 100,000 iterations of a 40 car box car train, composed
of cars chosen randomly from every possible prototype. The National
% is obvious, and then he finds the AVERAGE % found for that railroad
in the random consists. What is not obvious about this?


I tallied the maximum number of cars for each railroad over all the
iterations. In a 40 boxcar train, the average number of cars would be
40 times the national percentage shown in the above table."
Why do you say that?
Because he described it obscurely. He simply kept track of the largest
number of cars seen for each reporting mark in the 100,000 trains. Is
this not also obvious?


Well...actually that's not so at all. The correct number is 4. 136/34
If you use real...rather than theoretical data.
Real what? 136 box cars? 136 trains? 136 days? 136 train consists?

Larry's example was PURELY theoretical, and he made an excellent point.
I guess some people just don't get it.


We know that there were 4 of 34 trains...11.76%...of the trains with
far more than 9 SP bx cars.
Mike, you are having trouble grasping the idea. Larry has presented
100,00 theoretical trains, of fixed length, of random composition.
You persist with your miniscule sample of 34 actual trains of
varying length and composition of different sorts of cars (not just
box cars).


The 1953 data shows the "infamous" train with 36 or more SP box cars
[not T&NO ].
Yes, but I will argue that the Overland Route for the UP and SP was
a 'home road extension' in that each road was highly dependent on the
other for traffic. Therefore we can discount the presence of SP as
well as UP cars in all trains over Sherman Hill, for the purposes of
this discussion. This is exactly the "skew" that each layout has to
consider.

Tim O'Connor

Re: Freight car distribution

Mike Brock <brockm@...>
 

Tim O'Connor writes:

"Good work, Larry! That's what I'm talkin' 'bout!
A 40 car train with 9 SP (not counting T&NO) box
cars.."

I assume you mean a train with 40 box cars. Actually the 1949 trains averaged 82.3 cars.

"More than 5 times the 'average' value of
1.6."

I'm not certain what the 1.6 represents. The actual number is 4.

Mike Brock...I never thought statistics could be fun.

Re: A Purpose For Frt Car Distribution Studies. Was: Re: Re

Mike Brock <brockm@...>
 

Steve Lucas writes:

"Tony--

After reading this thread for some time, I have to agree with your
basic premise. Most major through transcon routes such as the UP in
Wyoming would very likely have over a given period, percentages of
each road's boxcars in keeping with the national averages. The law
of averages supports this."

Well...perhaps someone's law of averages supports it but the data does not. Can you explain that?

Mike Brock

Re: Freight car distribution

Mike Brock <brockm@...>
 

Larry Ostresh writes:

"I ran my "random train" Excel program for 100,000 iterations to test
whether it was working OK. The average number of boxcars per train,
by railroad, seemed to properly mirror the national fleet as
represented by Tim Gilbert's data for 1949:"

Larry, could you explain what you are talking about? You show RR [ i.e., SP excluding T&NO ], number [ number of SP box cars { 27757 } ] Nat'l % [ you show 4.0% but Tim shoed 3.9% ] and Random % [ 4.01% ]. What is the derivation of the random %?

RR___Number___Nat'l %___Random %

SP-Pac___27,757___4.00%___4.01%

"(The "Number" and "Nat'l %" columns above are from Tim's 1949 list of
boxcars."

Yep.

"His data are at "4060totalboxcarsUSownership.xls" in the
files section of this list."

Yep.

"The "Random %" column is the average
percentage of cars per train generated by my Excel program after
100,000 iterations. Each train consisted of 40 boxcars.)"

Hmmm. Well, 40 box cars is OK...actually 39.

"While running the program, I tallied the maximum number of cars for
each railroad over all the iterations. In a 40 boxcar train, the
average number of cars would be 40 times the national percentage
shown in the above table."

Why do you say that?

"For example, the average number of SP-Pac
cars would 40 * 4% = 1.6 cars - 1 or 2 cars per train."

Well...actually that's not so at all. The correct number is 4. 136/34= If you use real...rather than theoretical data. IOW, the 4% [ actually 3.9% ] fails to produce the actual number of cars...136.

"Any
particular 40 boxcar train may have more or less SP-Pac cars (0 to
40)."

"After 100,000 trials, there were in fact trains with no SP-Pac
boxcars, but no train had more than 9 of them."

We know that there were 4 of 34 trains...11.76%...of the trains with far more than 9 SP bx cars.

The 1953 data shows the "infamous" train with 36 or more SP bx cars [ not T&NO ].

Mike Brock

Re: A Purpose For Frt Car Distribution Studies. Was: Re: Re:Fwd: Re: Freigh

Bruce Smith
 

On Fri, August 15, 2008 5:45 pm, devansprr wrote:

But I do not have good info on details such as tank car manufacturer
type (e.g. 11, 21, 27, etc). If that exists let me know and I'll search
for it - there is a wealth of data in this site - it could use a full
word index system for quicker and more accurate searches.

Tank cars - (Information from Tim Gilbert summarizing the January 1943 ORER)
Union Tank Car Co. 38,707
General American Transportation Co. 27,867
Pennsylvania-Conley Tank - div. of GATX 10,327
Shippers Car Line 6,949
Sinclair Refining Co. 6,447
AT&SF 3,567
US War Department 2,475
SP - Pacific Lines 2,219
Gulf Oil Co. 1,551
UP 1,096
Dupont 1,068
Sun Oil Co. 1,035

However, given that the ORER does not allow us to decipher types, and tank
car companies were notorious for mixing cars from multiple makers into
series, the best I think we can do is try to convey the impression of the
WWII fleet.

Some rules of thumb -
-UTLX had the biggest fleet so the X-3 would likely be the most common
tank (Lots of Sunshine kits!) and IIRC, the 8K size was NOT the most
common (10K?)

-AC&F production of type 21 cars outnumbered type 27 by a significant
margin, and the 8K size was the most common of the type 21s.

-GATC built tanks were fairly common and we have no reasonable model in HO
for a fleet.

-"Oddballs" such as the UTLX "van Dyke", and earlier type 7 and 11 tanks
should not appear in great numbers, but were certainly in use.

So, for now, a fleet of Sunshine and Walthers/P2K tanks with a few
Intermountain, Precision Scale, Speedwitch (NATX tanks), IM/Tichy bashed
USG-A, Southern Car and Foundry (STC cars) and whatever else I've
forgotten (like the RC brass GATC cars and other brass cars) will make a
reasonable fleet with the exception of missing GATC cars. Like boxcars,
this approach will give you the varying sizes and features seen in WWII
era "pipelines on rails"

See my other post, but I thought most WWII era refineries were north of
the gulf - the off-shore oil had not been developed yet.

During WWII, the tank cars and pipelines carried crude oil and not refined
products to the refineries in the NE. Those fields, as others have noted
were onshore fields in Louisianna and Texas.

Regards
Bruce

Bruce Smith
Auburn, AL

Re: Union Pacific Stock car class

Rich Yoder
 

Thank you Tony.
What car class was that equivalent to on the SP?

Sincerely, Rich Yoder
7 Edgedale Court
Wyomissing PA 19610-1913
610-678-2834 after 6:00PM est until 10:00PM
www.richyodermodels.com

-----Original Message-----
From: STMFC@... [mailto:STMFC@...] On Behalf Of
Anthony Thompson
Sent: Sunday, August 17, 2008 6:16 PM
To: STMFC@...
Subject: [STMFC] Re: Union Pacific Stock car class

Rich Yoder wrote:
Yes I mean UP #46759.
What class was that car?
Class S-40-6.

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


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Re: DTI trucks

Brian J Carlson <brian@...>
 

Thanks. I must be thinking of the 70 ton trucks.
Brian J Carlson P.E.
Cheektowaga NY

----- Original Message -----
From: "Brian Leppert" <b.leppert@...>
To: <STMFC@...>
Sent: Sunday, August 17, 2008 6:32 PM
Subject: [STMFC] Re: DTI trucks


Brian,

If you're thinking of Pennsy's 2D-F12 truck, then no. It's different.
It has the distinct V-9306 sideframe with room for only one leaf and
two coil springs, whereas the trucks on my list of users are all double-
truss sideframes with two coil springs to each side of the single leaf
spring. Pennsy did have double-truss 70-ton versions with a pair of
leaf springs surrounded by four coil springs.

Brian Leppert
Tahoe Model Works

-- In STMFC@..., "Brian J Carlson" <brian@...> wrote:

Add PRR to the list.
Brian J Carlson P.E.
Cheektowaga NY
----- Original Message -----


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Re: DTI trucks

Brian Leppert <b.leppert@...>
 

Brian,

If you're thinking of Pennsy's 2D-F12 truck, then no. It's different.
It has the distinct V-9306 sideframe with room for only one leaf and
two coil springs, whereas the trucks on my list of users are all double-
truss sideframes with two coil springs to each side of the single leaf
spring. Pennsy did have double-truss 70-ton versions with a pair of
leaf springs surrounded by four coil springs.

Brian Leppert
Tahoe Model Works

-- In STMFC@..., "Brian J Carlson" <brian@...> wrote:

Add PRR to the list.
Brian J Carlson P.E.
Cheektowaga NY
----- Original Message -----

Re: Union Pacific Stock car class

Anthony Thompson <thompson@...>
 

Rich Yoder wrote:
Yes I mean UP #46759.
What class was that car?
Class S-40-6.

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: Union Pacific Stock car class

Rich Yoder
 

Yes I mean UP #46759.
What class was that car?

Sincerely, Rich Yoder
7 Edgedale Court
Wyomissing PA 19610-1913
610-678-2834 after 6:00PM est until 10:00PM
www.richyodermodels.com

-----Original Message-----
From: STMFC@... [mailto:STMFC@...] On Behalf Of
dmueller183@...
Sent: Sunday, August 17, 2008 5:43 PM
To: STMFC@...
Subject: [STMFC] Re: Union Pacific Stock car class

You mean 46759? There is no 46795 in the 1940, 1950, or
1953 ORER's.

...and ditto for july 1959 dave





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