Atlas 11K Gallon Tank Car

Published: 2020-12-19 - By: CNW400
Last updated on: 2021-01-01
visibility: Public - Headline
In May & July of 2020, Atlas Model Railroad expanded their Master Line American Car & Foundry 11,000 gallon tank car collection. This Master Line Series offers greater attention to detail and frequently includes separately attached metal and plastic parts.

Road Names and Pricing

This Master Line release includes nine different paint schemes. The road names represented in this collection include:
  • Allied Chemical (NDX)
  • Dow Canada (CGTX)
  • Foley Butane (FBCX)
  • Mississippi Chemical (MICX)
  • Panoma (PANX)
  • Shamrock (SOGX)
  • Shell Chemical (SHPX)
  • Tidewater Associated (TWOX)
  • Warren (WRNX)
Two different road numbers are assigned for each rail line.

The suggested retail price is $35.95. An undecorated version is available with or without dome platform for $25.95.

My review includes observations of Atlas stock number: 50 004 743 - Shell Chemical (SHPX) #1618.

Prototype History

Tank cars were one of the first all-steel pieces of rolling stock – from the early 1900’s throughout the 1950’s their basic design went unchanged. A riveted horizontal tubular-shaped tank with a dome .The tank rode along a separate steel underframe, sitting in a saddle and anchored to the frame with a series of narrow bands wrapped around the tank to the frame. The tank was not riveted to the underframe – allowing for expansion and contraction of the tank.

Potomac Yards Tank Cars ca. 1920’s
Credit: Theodor Horydczak Collection, Library of Congress, Prints and Photographs Division, Public Domain

The tank cars original cargo was crude oil from the Pennsylvania fields in the late 1860’s. Merely tanks mounted onto flatcars to transport oil evolved into 140,000 steel tank cars hauling over 100 different commodities by the 1930’s.

Pre-World War II, propane became a popular option in the rural areas of America for cooking and heating. The demand for anhydrous ammonia also increased during this time. Anhydrous ammonia is a chemical compound used in several applications: industrial cleaning, agriculture, fertilizer production and drug manufacturing. It is labeled anhydrous because it contains no water – it is over 99% pure ammonia. In contrast, household ammonia is a diluted water solution containing 5-10% ammonia. The Atlas model for review, amongst others in this series, is marked to carry anhydrous ammonia. After the war, the railroad industry built new tank cars to transport these commodities. Special high-pressure tanks were developed with thicker shells and replaced riveted construction with welded tanks & underframes. The major builders in this era included: General American – built for Union Tank Line (UTLX & GATX) and American Car & Foundry (ACF) for their Shippers’ Car Line (SHPX).

Railroads were reluctant to invest into rolling stock that hauled a single commodity (similar to stock cars). Instead, leasing companies provided privately owned tank cars to customers. GATX and UTLX handled the bulk of the tank car lease fleet. Shippers’ Car Line (SHPX), a subsidiary of American Car & Foundry started in the 1927 was a distant third. In 1955, 96% of all tanks in service were privately owned (leased). Most railroad owned tank cars were in company service hauling locomotive fuel or water, not revenue generating business. Tank cars on a ten-year lease were painted with the company markings. A lease with shorter terms only had the company markings stenciled two-feet tall. Throughout the 1950’s privately owned tank cars in service out numbered all other leased cars combined.


Union Tank Line38,800
General American33,500
Shippers’ Car Line9,200
North American4,500
Warren Petroleum4,300*
U.S. Department of Defense3,100
Shell Oil3,000
Fleets with at least 3,000 cars
*Warren is an estimate
Source: Official Railway Equipment Register

Common sizes for tank cars during this era were 8,000 – 12,000 gallon. The size tank was dependent on the load size requested by the customer and the weight difference amongst products. The American Association of Railroads (AAR) did not mandate a standard for tank cars, thus a variety of designs were created. Sulfuric acid and chlorine are heavy commodities, thus demanding a smaller tank car. Gasoline and propane are lighter products and can be transported in larger tanks.

Commodity Weight and Density (Pounds/Gallon)

Anhydrous Ammonia5.0
Crude Oil7.5
Corn Syrup11.5
Sulfuric Acid15.0
Brief List of Commonly Shipped Products
Source: Model Railroader

ACF built 1,500 Type27 tank cars in 1946 to meet the increased demand of shipping propane, chlorine, anhydrous ammonia and liquid petroleum gas (LPG). LPG is a mixture of mostly propane and butane. Propane in its natural state, the predominant component of LPG, is a gas. When compressed under sufficient pressure it turns to its liquid state.

The sizes of these 1946 ACF cars were either 40’ or 42’ in length with 10,500 or 11,000-gallon tanks. In 1947, ACF built another fleet of 11,000-gallon tank cars with a length reduction to 39 feet. Most of these cars, about 75%, had non-pressurized tanks carrying most liquid products such as gasoline, oil, ethanol, vegetable oil, ink and corn syrup. The balance was a Type27 ICC-105W tank car suitable for gasses and chemicals under pressure.

American Car & Foundry initially developed four 10,000 gallon pressurized cars in 1926 for Carbide & Carbon Chemicals. Their earliest 11,000-gallon pressurized cars were anhydrous ammonia tanks created for Mathieson Alkali Works in 1927.

American Association of Railroads (AAR) Tank Car Codes

TMGeneral Service, non-insulated
TAAcid Service
TLEquipped with Special-lining
TGGlass-lined Car
TPPressure Tank Car
TWCar with one or more tanks or tubs
An “I” suffix with any of these codes indicates an insulated car
Source: Model Railroader

The basic tank had a handrail that ran horizontal around the entire car, running boards, a ladder to access the dome hatch (called a manway) and end sills. Depending on customer preference and the loading procedure, access to the manway atop the dome was either accomplished with a simple ladder and small step platform or a platform built around the entire manway with railings. Furthermore, the manway needed to be opened during the unloading of liquid product. Air needed to vent into the tank to help “push” the product out more quickly and the vacuum created during unloading could cause the tank to collapse if the proper air pressure was not maintained in the tank.

Tank cars can have two or more compartments – each compartment will have its own dome. Cars with the same size multiple domes were constructed for that purpose. Tanks with different sized domes (i.e. large in middle with two smaller ends) were converted into multiple compartment cars. Non-pressure cars can be unloaded from a top or bottom outlet. A hose or threaded pipe is connected to an unloading valve. Pressure cars are unloaded from outlet connections located in a housing on top of the tank. Three connections are used for unloading and venting: two for removing the liquefied product and the third for vapor. The connections are colored red for liquid and yellow for vapor.

Non-pressurized cars were insulated with either cork or foam and covered with thin steel sheathing. These cars could also be equipped with steam heating coils to assist viscous liquids, such as tar or corn syrup, flow more freely during unloading. Pressurized cars were insulated with external steel sheathing and do not have heating systems.

The most common color from tank cars was black. In theory it hid the stains and spillage of most commodities and it is a basic, inexpensive paint selection. Anhydrous ammonia cars were often painted white. Tanks hauling acids were white with wide vertical bands at center. Hydrocyanic acid cars, also called candy-stripe or candy cane cars, had white tanks, a thin horizontal stripe across the center and vertical red stripe above each truck. Tank cars hauling hazardous materials had four HAZMAT placards: one on both sides of the car and one on each end. The placard color is based on the material being transported and if it is flammable, corrosive, reactive or an inhalation hazard. Empty tanks have no placards posted. Furthermore, cars needed to be stenciled with the lading being transported.

Once the 1950’s arrived the railroads lost a great of their fuel hauling traffic to pipelines and the trucking industry with the expanding highway system. The railroads tried to combat this lost of business with the development of larger tank cars to make it more efficient to use rail service and targeting the expanding chemical, rubber & plastics industries in North America.

General Dimensions (1947-1950) 11,000-Gallon, Type 27 Tank Car

Truck Centers: 27'-11"
Length (over end sills): 38'-5 1⁄8"
Length (over strikers: 38'-6 1⁄2"
(over running boards): 9'-8"

Capacity (Gallons): 11,000
Diameter (inside): 89 1⁄4"
Length (inside): 35'-2 7⁄8"

All cars had 4" fiberglass insulation surrounding steel tank. 1⁄8" steel jacket, 6 overlapping sections, welded.

Source: St. Louis Area Railroad Prototype Modelers

The Model

The ready-to-run boxcar comes packaged in a clear plastic jewel case with a slip-off cover and a one-piece plastic cradle to cushion the model. The model information is clearly labeled on the end of the case for ease to locate when in storage. A thin plastic film was wrapped around the car to protect the print job from scuffmarks. No additional detail pieces were found in the packaging.

Shell Chemical car with jewel box

My first impression was very pleasant. The car has a nice heavy feel - it has a good weight and the sense of solid construction when in hand. The full body handrail, dome platform and brake wheel are finely detailed but are also fragile and great care is needed when handling. This model is equipped with brown plastic wheels, which is rather disappointing for a $36 Master Line product.

The Shell Chemical tank car light grey paint job is clean and even along the entire injection molded plastic model (it looks like a dirty white color). The underframe and all piping & rails are black. Lettering is extremely sharp and clear, even when magnification is needed for the smaller printing. The Shell Chemical name is painted red and all other markings are printed black. These letters are crisp with no signs of running colors. The car is stenciled for anhydrous ammonia service.

Sharp and Crisp Lettering

My research failed to discover any Shell Chemical cars with the SHPX road markings. I was able to find several examples of tank cars with the SCMX designation. The prototype car used for this review is a 1954 photograph of Shell Chemical SCMX #2134 - also used to haul anhydrous ammonia. The color, placement and size of printing are accurate when compared to the prototype image. The left side of the tank features the reporting mark & number, the load limit and light weight. The right side clearly displays lease details, year built, tank contents and other data details. Also visible is the Interstate Commerce Commission car classification number of ICC 105A 300W (105 = insulated, high pressure car class designation / A = top and bottom shelf couplers / 300 = test pressure (PSI) / W= fusion welding).

The sides also feature finely molded handrails, center ladders to dome platform, hazard placards and the correct six-welded section tank body. All details are identical to the prototype car.

The tank ends display the road marking, car number and capacity in gallons. Both ends also have a HAZMAT placard - all of these are consistent with the real-life photograph. The B-end features a fragile (careful not to bend) separately applied geared-type hand brake that is the proper height when compared to the prototype.

Tank ends with accurate markings ad HAZMAT placards

B-end features a proper height hand brake

The single-dome tank car top features an Apex full-surround dome platform complete with safety railings and excellent detail on the manway. The dome platform in reality measured 6’-6” x 4’-7”. If I have to be critical, there was plastic flashing that need to be cleaned from the platform holes. But all is forgiven - this is N-scale after all and the detail work is fantastic on this model.

Platform and Manway

The black underframe features Apex Tri-lok running boards along the tank. The underside has an elaborate arrangement with highly detailed separately applied cylinder, reservoir, control valve and brake gears & rods. These underside-braking components are very visible both on the prototype and model and are represented wonderfully by Atlas in this release. The tank car rides along 50-ton friction-bearing trucks and brown plastic wheels. Furthermore the model is equipped with truck-mounted AccuMate couplers and both were mounted to the proper height on each end.

Highly Detailed Braking System and Underframe

The car is 2 7/8 inches in length and weighs about 0.9 ounces, which is perfect according to the National Model Railroad Association (NMRA) recommendations (which are 0.9 - 1.0 ounces for this size car). I found it a great runner while testing the car on Kato Unitrack with no issues around curves or through turnouts at slow and medium speeds. In the future, for my own personal preference, I will upgrade the wheel sets to black metal wheels.


I hope Santa puts some more these in my stocking. This is a dynamite release by Atlas. A highly detailed model that is true to the prototype. It’s also an excellent runner that needed no adjustments to perform smoothly. While I must admit I have a soft spot for tank cars (how can you have too many tank cars?), I would highly recommend the newly released Atlas ACF 11K Tank Car to be featured on your transition era layout.

About the Author

CNW400 became enamored with trains while watching the ‘Green & Yellow’ double-decker cars clad with shiny green windows (C&NW) rumble by his childhood house in Chicago. His first train set was the Tyco Bicentennial model in 1976. Always a fan of the railroad, CNW400 is newer to the hobby, active for the last four years (now that all the kids are grown-up!). Furthermore, he is also a collector of railroadiana focusing on lanterns, locks & keys and insulators.