In the 1920s, the Pfaudler Company and General American Car Company manufactured hundreds of 40' wood sheathed, insulated milk cars. Designed as bulk milk carriers, the cars were built around two 6,000 gallon glass lined tanks and a brine cooling system, designed to keep the milk at a constant 38 degrees Fahrenheit. Riding on passenger car trucks, these unique wood sided cars were often painted Pullman green to match the color of the most common passenger cars of the era. These specialty cars hauled bulk milk into the early 1950s .

In 1932, Pfaudler and General American merged and became the General American Pfaudler Corporation. Reporting marks became G.P.E.X. instead of the earlier G.A.R.E. of General American.
According to the General American Car Company brochure of 1928 these cars are used for:
• Transporting whole sweet milk from country receiving plants to city distribution plants.
• Hauling concentrated milk from “feeder” plants to main condensing plants for “finishing off” the product.
• Shipping sweet cream from rich dairying sections to the metropolitan markets.
• Transporting ice cream “mix” from the milk producing regions to the city plants for freezing.
• Transporting skim milk from country plants to various users.

General American cited a number of advantages that this design had over the traditional “milk can” cars:Loading Advantages and Savings
• Milk is loaded directly from the cooler to the car through sanitary piping.
• Can washing is eliminated.
• Avoids spillage which is incurred in can shipping.
• Elimination of cans reduces investment.
• Labor is reduced in every step of loading and unloading . . . .
• No icing is necessary, eliminating cost of ice and labor.
• One refrigerator milk car has a capacity equal to three of the usual milk can cars.
• Eliminates losses due to frozen milk adhering to sides of cans in severe winter weather.
• There is approximately one fifth the surface in a refrigerator milk car as compared to cans required to carry a like amount.
Consequently, the adherage of milk in refrigerator cars is but a negligible fraction of the usual loss in cans.
Quality and Safety
• Authorities agree that glass lined receptacles are ideal for storing or shipping human foods. Quality is maintained.
• Bacteria count is controlled, not merely influenced as under the old transportation methods.
• Average variation of temperature of milk in transit, has been negligible during periods as great as one hundred hours under the most severe climatic conditions.

Economic Advantages
• Dairy products can be shipped distances many times greater than under the old methods.
• Dairying regions are benefited because the output of the producers is maintained at higher quality in shipment and this is reflected in their financial returns.
• Because of the money savings and improvement in quality of product through use of the refrigerator milk car, the dairy industry profits. The benefits are cumulative.

A most interesting and informative article on milk cars was written by Bob Schleicher and published in the August 2005 issue of "Railmodel Journal" magazine.

Key Features

• Fully assembled and ready to operate
  
• Separately applied brake wheel
  
• Screw mounted trucks for accurate tracking
  
• Truck mounted magnetically operated knuckle couplers
  
• Plastic wheels