This review is from Model Railroad News, Vol. 6, Issue 12, December 2000. Reprinted with permission of Lamplight Publishing.

The new Atlas “Big O” Airslide                   

Review by David Otte

Atlas O 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.

The Prototype

If it 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 expedient manner.

So the 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.

The 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 chemicals,

The 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.

Although 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.

The Atlas O Model

As you 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.

The quality 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.

We obtained 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.

The paint 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!

As always, 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.

The Rio 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 City, Utah.

An 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 style trucks.

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 track.

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.

Final Thoughts

The 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 Atlas O!