Cork insulation; a complete illustrated textbook on cork insulation ...

REFRIGERATOR CARS 451
vegetables and dressed poultry have been shipped in these cars and
sometimes they have been loaded ahnost to their cubical capacity!
The relative value of the air space and paper as an insulator
may be further emphasized by comparing a car built with what is
termed, especially in the south, "a double-felt-lined" car. Such a
car is considered to be a greater protection than a box car but in
no wise is it a refrigerator. Indeed, it is not provided with ice
bunkers. Chart XVI shows how the temperatures on the ceiling of
such a car follow the atmosphere. Compare its performance with that
of the paper car on the same chart, and I think you will agree with
me that there is a decided similarity between the two.
Summary
Summing up the results of such experiments as these we are led
to the following conclusions:
1. A combination of basket bunker, insulated bulkhead and
floor rack, produces a circulation of air which is not obtained in a
car having a box bunker, open bulkhead and bare floor or permanent
strips.
2. Such a basket bunker car, approximately 33 feet between
bulkheads, can refrigerate the top and bottom of the load in the
two middle quarters of the car, provided it is sufficiently well insulated
and not overloaded.
3. Cars which depend for <strong>insulation</strong> on paper and air spaces
should not be used for the transportation of such perishables as
fruit, delicate vegetables, poultry, eggs and fish.
4. Cars having one inch of <strong>insulation</strong> will not carry eggs suc-
cessfully during hot weather when loaded more than three layers
high.
Cars having one and one-half inches of <strong>insulation</strong> in the side
walls and two inches in the roof and floor will not carry eggs suc-
cessfully during hot weather when loaded more than four layers
high.
Cars having three inches of <strong>insulation</strong> in the roof, two in the
side walls and ends, and two inches of cork in the floor will carry
• eggs five cases high, but not six.
The box bunker car, regardless of quantity of <strong>insulation</strong>, does
not refrigerate the two middle quarters of the load when it is tightly
stowed. Even with an open load the performance is unsatisfactory.
5. The use of salt with the ice in a well insulated basket bunker
car will permit an increase in the load of from 25 to 40 per cent.
6. While each commodity must be studied separately in order
to determine the maximum load, the principles of the relation between
car efficiency and tonnage of eggs as indicated in this discussion
can be applied to perishables in general.