On Jul 21, 2015, at 1:41 PM, 'Gatwood, Elden SAW'
elden.j.gatwood@... [STMFC] wrote:

>  Yes, there is a stack of cars from which they can choose, for this
> relatively common late forties-mid-fifties six-sheet(course) jacketed
> 11k 105. This is a car really good for rural LPG/propane use, as well
> as urban setting compressed gas. I think this is a considerable
> improvement over the Atlas car, but you may not agree.

Elden, Tim, Dave. and others with interest with this thread,

This is long, but please bear with me to explain the Kadee and Atlas
cars and the prototype cars they represent (or in the latter case
supposed to represent).

From a distance the two models may appear similar in overall
appearance, but closer inspection shows the Kadee and Atlas models are
actually based different ACF underframe designs. While both models are
based on ICC-105A tank cars having 11,000-gal. nominal capacity
typically used for transporting liquified petroleum gas or anhydrous
ammonia, the prototype cars were built at different times except for a
concurrent production period in 1948-1949 of just 5 lot numbers and 58
cars. Consequently, despite the Atlas model having a number of issues
that are discussed later, the Kadee model should not be considered an
upgrade of the Atlas model. Both models should stand on their own as
representing prototype cars in which there should be no duplication
whatsoever.

I don't want to get into the weeds too deep, so I'll address only a few
major points about the ACF production cars built that are the basis of
the Kadee and Atlas models.

The Kadee Model:

The Kadee model follows an ACF general arrangement drawing (41-13161)
used by ACF to build prototype cars from 1947 to late 1950 with Type 27
riveted underframes having the familiar 9" rolled-channel side and end
sills. The underframe has a 27'-11" truck center spacing, length 38'-5
1/8" over the end sills, and width 9'-8" over the running boards. The
three AB brake parts are on the same side of the center sill with the
AB valve directly above the reservoir.

The earliest prototype cars (SHPX 2786-2955, inclusive) that applied to
the ACF general arrangement drawing were built from March to July 1947
having wood running boards & dome platforms. Starting in July 1947 and
continuing to Oct. 1950, prototype cars of this design received Apex
open-grid running boards & dome platforms, which the Kadee model
depicts. If the modeler is so inclined, the Kadee model can be modified
to represent the earliest 170 SHPX cars by removing the Apex hardware
and substituting to simulate wood running boards & dome platforms.

All of the prototype cars that the Kadee model represents came with
1/8" steel jackets that surrounded 4" of insulation around a tank
having an 89 1/4" inside diameter. The jacket design was comprised of
upper and lower portions forming a cylinder and connected lengthwise on
each side with a pair of 2" x 2" angles. The upper portion comprised
roughly 2/3 of the jacket's circumference. Lengthwise, the jacket
design had six overlapping sections of approximately equal length, thus
five welds around the jacket circumference. One weld was located at the
longitudinal dome center line. There are no exceptions to this jacket
design for the cars built on Type 27 underframes from 1947 through Oct.
1950.

ACF production of this design from 1947 to Oct. 1950 yielded 1,650 tank
cars built to the same general specs (about 45 lot numbers). Of the
total, 1,480 cars came with Apex running boards & dome platforms. Dome
platforms were of two general types: (a) a pair of side dome platforms
typically 4' in length, and (b) dome platforms that surrounded the dome
having a standard size of 6'-6" (lengthwise) by 4'-7" (crosswise). The
first Kadee release (TWOX car) has the side dome platforms, and when
future releases of Kadee models that have the full dome platform I have
been advised they will comply with the stated dimensions.

Shippers' Car Line (SHPX) had the most with 725 cars that were leased
to many companies. Some were on long-term lease (likely 10 years from
the build date) with larger company stencils and others on short-term
lease having small 1" "lease to" company stencils. Warren Petroleum Co.
(WRNX) was also a major buyer and received 600 of them. Union Tank Line
(UTLX) bought a relatively small quantity of these cars. The balance
went to Republic Tank Car Co. (RTCX) and a variety of small companies
mainly for propane distribution.

The Atlas Model

Since I didn't work with Atlas on the project development, I don't have
insight to what technical data was used for product development. Based
on the Atlas model's appearance and features, it follows an ACF design
having a welded underframe that lacks the 9" channel side & end sills.
The ACF welded underframe, instead, was built with flat-plate side and
end sills that met at the corner with a small radius. ACF welded
underframes had the brake parts split with the cylinder and AB valve on
the left side of the center sill and reservoir on the opposite side,
which the Atlas model follows.

ACF began to experiment with welded tank car underframes with the
earliest being on cars built in late 1945 to early 1946. More cars of
various ICC classes and sizes were built on welded underframes during
1947-1950 as ACF transitioned from the Type 27 riveted design to welded
underframes. As of 1951 the Type 27 underframe, for all intents &
purposes, had been phased out.

For ICC-105A, 11,000-gallon capacity tank cars, the ACF welded
underframe was the same length (38'-5 1/4" over end sills) as the
previously-described Type 27 underframe. Other dimensions and the brake
arrangement were different with a standard truck center spacing of
28'-2 1/2" used on cars of this type. While this dimension is 3 1/2"
longer than the Type 27 underframe design, the truck center spacing on
the Atlas model measures approximately 27'-5". The Atlas underframe
length and width dimensions measure the same as the Type 27 design.

The ACF standard welded underframe width for cars of ICC-105A class and
11,000-gallons started off in 1948-1949 as 9'-8" and grew 4" to 10'-0"
by 1950 for subsequent production. Thus, about 98% of ICC-105A,
11,000-gallon production tank cars on welded underframes from 1948 to
1954 was on 10'-0" wide welded underframes. All ACF prototype cars of
this type with welded underframes typically came with Apex Tri-lok
running boards & dome platforms, or equivalent such as Blaw-Knox. These
features are not correctly depicted on the Atlas model that has solid
running boards and dome platforms made to resemble Super Diamond Plate.
Also, the size of the Atlas full dome platform measures 7'-10"
lengthwise by 4'-11" crosswise. This is significantly oversize and not
proportioned correctly. I have not found any prototype cars of this
type on welded underframes with dome platforms of this size.

Regarding the tanks and jackets, early ACF production tank cars on
welded underframes received the same tanks and jackets as the cars
built with Type 27 underframes (i.e., jackets with six overlapping
sections). In 1952 ACF changed the jacket design going to five sections
and four welded joints around the circumference. More often than not,
subsequent production cars had five-section jackets. For all of the ACF
11,000-gallon, ICC-105A tank cars built from 1948-1954 with welded
underframes, I estimate that about 50% of the 2,300-plus production
cars were built with 5-section jackets, 35% with 6-section jackets, and
15% with a third variation used in 1951 with lengthwise jackets welded
longitudinally.

As indicated earlier, theoretically, the Atlas and Kadee models should
not have any duplication of the reporting marks & car numbers. The
Atlas model has been around for a number of years, and suffice it to
say that Atlas has taken some liberties on the paint & lettering
schemes they have produced. Some Atlas models have either an incorrect
jacket (should be five section or the third variation) or they have
applied a paint/lettering scheme that should have been on a Type 27
underframe instead of their welded underframe. No crime, but I point
this out to help distinguish the relative accuracy and to say that
Kadee will likely duplicate schemes used by Atlas because they will be
correct for the Kadee model.

While this message is quite long, I hope this helps STMFC members
interested in the 1947 and later period to better understand the
prototype ACF ICC-105A, 11,000-gallon tank cars and how the Kadee and
Atlas models reflect the prototypes for which they are intended to
depict.
Regards,
Ed Hawkins