Re: What defines an AAR boxcar?

Dennis Storzek

--- In, Ed Hawkins <hawk0621@...> wrote:

On Dec 15, 2006, at 12:48 PM, Kurt Laughlin wrote:

As best as I can tell, there were four main types: 1937, 1937
(modified), 1944, and postwar. What distinguishes theses from each
other? I'm pretty sure that 40-6 x 9-2 x 10-0 cars are the 1937 types
and that 40-6 x 9-4 x 10-6 cars are postwar, but what are the others
and how much leeway in dimensions is there within a type? For
looking at RPC 4 pages 12 to 34 I see:

NC &STL 18850 9-2 x 10-0 "1937 AAR"
CB&Q 35000 9-4 x 10-6 "AAR" (blt 5-47)
ATSF 143510 9-2 x 10-4 "1937 (modified) AAR"
CNW 71028 9-2 x 10-5 "1937 (modified) AAR"
CNW 80606 9-2 x 10-6 "1937 (modified) AAR"
UP 197899 9-2 x 10-6 "1944 AAR"
SOUTHERN 23399 9-2 x 10-6 "AAR" (blt 8-47)
MP 37447 9-2 x 10-6 "AAR" (blt 8-57)

Thanks in advance,
Since you specifically called out some RP CYC references, I'll comment
and provide some specific references. To begin, Richard and Tony are
right when they say it's not an easy question to answer!

For background, the Car Builders' Cyclopedias, which use A.A.R.
terminology, specify the "1937 A.A.R. design" (i.e., page 110 of the
1940 CBC). Generally, this design was for a standard 40'-6" box car
with 10'-0" IH (some variations existed). The majority of these cars
had Dreadnaught Steel Ends (4/5 corrugation pattern) and Murphy raised
panel roofs, however, there were box cars built that met the design
criteria having other ends and/or roofs (such as Buckeye ends,
Pullman-Standard Corrugated Ends, 5/5 Dreadnaught Steel Ends used by
CP, "NSC" ends used on numerous CN cars, Viking roofs). Prior to this
was the 1932 A.A.R. box car (originated by the A.R.A.), and a drawing
of this car is shown on page 113 of the 1940 CBC. The standard IH was
9'-4". Again, there were variations of the inside height, and there
were all kinds of variations of roofs and ends, causing this "standard"
car to be anything but standard from the standpoint of a plastic
manufacturer thus far unable to justify tooling cost. To this day we
have no good plastic models of the 1932 "standard design" box car that
Ted Culotta wrote an entire book about.

In the 1946 CBC is a drawing and photo of an Erie 40'-6" box car
(81000-81799), and it states "Modified A.A.R. Standard" on page 110 as
part of the drawing title. It also specifies "Modified 1937 A.A.R.
design" on page 111 as part of the photo caption. These cars had an
inside height of 10'-4 3/8", and they were essentially the same as the
1937 A.A.R. design except taller and used 5/5 Dreadnaught Steel

As we know, "postwar" cars of 10'-4" to 10'-6" IH used a variety of
ends and roofs over 15+ years of production. In my rosters and
writings, I have used the term "postwar A.A.R. box car" not as an
official A.A.R. term, but to refer to a family of box cars generally
built from mid-1945 (first use of the Improved Dreadnaught End that I
could find) to 1960, where we cut off the discussion per STMFC
Ed Hawkins
I'm getting a chuckle out of all the different AAR standards, because
they don't exist.

I have before me a copy of a drawing titled:




DATE APRIL 1,1937 PLATE No.1500-K

This 1937 drawing shows a boxcar with R-3-4 IDE ends, a diagonal panel
roof, and the improved Youngstown door. How can this be, you ask?
Simple, this is revision "K" of the 1937 drawing.

In reality, when the design was adopted in 1937, it became THE AAR
standard boxcar, and simply went through a gradual series of
incremental changes from that point on. The dates of the revisions on
this plate are as follows:

A 12/31/37
B 8/3/40
C 3/15/41
D 6/25/42
E 12/1/45
F 4/1/48
G 3/1/51
H 6/24/54
I 3/1/56
J 12/1/57

And finally K, 4/1/62. There may be more, but not on my copy of the

Each and every one of these could be thought of as the AAR standard
boxcar of that particular date, or they could all be thought of as the
AAR 1937 standard boxcar, as revised. The only thing they are not is
the 1942 standard, or 1944 standard, or the Post War standard, except
in the most general terms. Those are just names that some modeler made
up somewhere along the line. In reality, we should be discussing the
"Revision C car", or the "Revision J car".

Do I know what changes were made to the standard at each revision?
Unfortunately not, as there is no revision notes included with the
drawings. But, that's no excuse for making up names to mask the lack
of knowledge. How about we just call the thing the AAR Standard
boxcar, with improved Dreadnaught ends and a diagonal panel roof, or
whatever, until we find out what the proper nomenclature should be?


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