review is from Model Railroad News, Vol. 6, Issue 12,
December 2000. Reprinted with permission of Lamplight
new Atlas “Big O” Airslide
by David Otte
continues their line of Big O Rolling Stock with the release
of their newest freight car—the General American Airsilde
Hopper. The car is available ready to run in either 2-rail
or 3-rail. The hoppers come decorated for: Delaware &
Hudson, Lehigh Valley, Rio Grande, Santa Fe, Firestone and
Jack Frost. An
undecorated version is also being produced. Two roadnumbers
are available per roadname. The O scale model is being
produced in China.
hadn’t been for cement, the Airslide Hopper may have never
been developed. In the late 1940s, the Fuller Company’, a
manufacturer of powdered cement, needed to find a new way
for delivering their product by rail. In the past, dry
granular cargoes such as cement or flour were packed in
barrels and then manually loaded or unloaded into boxcars.
Later, with the advent of the covered hopper, these
commodities could be hauled in bulk. But these types of
lading tended to pack down quite solid in the hopper making
it difficult to fully discharge from the cars in an
Fuller Company developed a covered hopper which embodied
some rather innovative technology. First of all, the new
design was based on an airtight car body which would prevent
the load from spoiling. Second, it featured an all welded
design with structural barking located on the outside of the
car. Without rivets or internal bracing, there was nothing
for the granular cargo to get hung up on during unloading.
The real breakthrough, however, was called the Airslide.
This process entailed lining the interior of the hopper with
an air-permeable, silicone-treated fabric. Sealing off the
underside of the fabric were U-shaped chambers. Low pressure
air was then released into these chambers which traveled up
through the fabric and caused the lading to flow down the
sides to the discharge hoppers at the center of the car.
Airslide design really made an impression on the railroad
industry for in 1954, the General American Transpiration
Company (GATX) purchased the Fuller Company and put the new
hopper into mass production. The GATX Airslide was used to
carry an assortment of commodities such as: flour, sugar,
starch, porcelain, plastic resins, baking soda, clays,
powdered metals, borax, oatmeal, boric acid, and other
Airslide found wide acceptance among railroads, as well as
manufacturers of dry bulk goods. Either leased from GATX or
railroad owned, the list of operators is impressive.
Railroads using the hopper at one time or another included:
the Atlantic Coast Line, Santa Fe, Burlington Northern,
Baltimore & Ohio, Canadian National, Great Northern,
Katy, Northern Pacific, MoPac, Seaboard Air Line, Frisco,
Union Pacific, Western Maryland, and others. Private
operators included: ADM, Anheuser Busch, Brachs, Champion
Spark Plug, Domino Sugar, Firestone, General Mills, Jack
Frost, Pillsbury, Quaker Oats, and the list goes on.
General American ended production of the original single
compartment, two-bay, 2,600 cubic-foot design in 1964, these
early production cars continued to carry much of the dry
bulk commodities traveling by rail throughout the 1960s and
1970s. Modified versions of the Airslide, however, continued
to be produced up until 1984.
Atlas O Model
might have already guessed from reading previous reviews of
Atlas O’s Big Rolling Stock, the Atlas O scale Airslide
Hopper is a very accurate rendition of the prototype.
Measuring just under 10-3/4”, or a scale 43’ long over
the coupler pulling faces, the Atlas O car compares well
with the dimensions of its real life counterpart. Other
measurements taken, including the wheel base at 7-3/8”
long and the height of the car above the rails at 3-38”,
scale out within inches of the actual wheelbase of
29’6”, and height of 13’ 5-15/16”.
The Atlas O
car matches prototype photos and drawings detail for detail.
The model appears to represent the original or classic
Airsilde design with the open ends and diagonal end braces.
Later versions of the hopper had wider external structural
ribs on the sides, as well as the addition of triangular
gussets on the ends.
of the injection molded plastic car body is excellent. And
there is a host of separately applied details as well. These
include: see-through roofwalks, opening roof hatches,
numerous metal grab irons, brake wheel, perforated brake
platform, diagonal end bracing, brake gear with underbody
linkage, hopper discharge doors, and air lines. The car
rides on sprung die cast metal trucks of either the
friction-bearing or roller-bearing design depending on the
roadname of the car.
review samples decorated for Jack Frost Sugar cane and the
Rio Grande. With as may operators of the Airslide as there
were, these cars appeared in some truly stricking paint
schemes. Our two samples are great examples of this.
application on both of our cars is first rate, with even the
white on the upper half of the Jack Frost hopper opaque.
There is no signs of any bleed-over between colors either.
The lettering and graphics are applied neatly, and all text
is readable down to the small caution signs at the bottom of
the car sides. These include, CAUTION: Always open
compartment hatches before unloading car—a rule to follow
on an air-tight car less one wanted the roof to collapse
from the pressure of the outside air!
Atlas O has done their research and both paint schemes were
accurately reproduced down to the car data. The Jack Frost
Airslide came with the reporting marks of a General American
leased car, GACX, and was appropriately numbered in the
42000-44000 leased unit number series. It was also equipped
with the proper friction-bearing trucks as delivered cars.
Grande version represents one of ten ordered from General
American in 1960, numbered 18100-18109. Five more cars were
added to the roster in 1962-63. Our sample was numbered
18109 and was used for carrying flour based in Salt Lake
interesting fact about the Rio Grande Airslides is that they
were the only freight cars to were the three color Main Line
Thru the Rockies herald. Atlas O has gain captured this
heralds in full color and has applied it to a separate sign
board as on the prototype. My only observation on this car
was that the sign board on one side of the car was applied a
bit crooked. In addition, Atlas O has followed the original
and has equipped the Rio Grande version with roller-bearing
On the test
track, our 3-rail samples of the Airsilde were able to
negotiate O-31 curved track and switches without a problem.
In fact, the cars will operate on O27 curves due to their
relatively short length. As with all the other true O scale
rolling stock though, the larger the curve diameter used the
more the realistic the car will look when running on the
As has been
our experience with previous Atlas O rolling stock tested,
the magnetically operated die-cast couplers worked well and
the metal wheelsets rolled very smoothly. Atlas O is
offering the GATX cars in 2-rail ready-to-run so there is no
need to buy a separate conversion kit if you are a 2-railer.
The 2-rail versions come equipped with plated metal
wheelsets and Kadee compatible couplers.
Airsilde Hopper compliments the other fine rolling stock
Atlas O has already produced, and will really add some color
to your consists. Its scale details should satisfy the
prototype modelers, while its small size will allow it to be
operated on the smallest of layouts. Another great job by