Reefer Notes
A post from the Rensselaer Model Railroad Society courtesy of Doug Harding
Refrigerator cars ("reefers") were used to carry lading, mostly food, that needed to be kept below the outside temperature.? (Sometimes the insulation allowed the contents to be kept from freezing, such as potatoes.)? Throughout most of the steam-era, the refrigerant was ice.? Melting ice water would spoil foodstuffs, so it had to be kept separate.
The most common way was to place the ice in bunkers at the end of the car. This was visible from the outside by ice hatches on the roof.
Wood sheathing for reefers was the norm for about two decades after box cars had switched to steel. It was felt that wood was a better insulator than metal.? Eventually they realized that steel was better at keeping the insulation in the walls from getting wet, as wet insulation ceased to insulate.
Reefers could carry milk, produce, or meat. Milk and produce had to be kept COOL, meat had to be kept COLD. In order to lower the melting point of ice below 32 degrees, salt was mixed in (just as it is used to melt ice on sidewalks).? But the resulting brine was extremely corrosive to steel, including steel rails.
Ordinary reefers allowed the meltwater to drain out of the bottom of the car. Meat reefers had to have special brine tanks to hold this.? Meat reefers typically also had to have "beef rails" to hold a whole carcass.
The most visible thing about meat reefers is that they typically were only 36 feet long overall as opposed to the almost universal 40-foot standard box car or produce reefer.? The mostly likely reason is that natural refrigeration was strained to keep a longer car cold enough. (Yes, all sorts of exceptions.)
Bob Chaparro
Moderator
Bob Chaparro