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

448 CORK INSULATION
the two inches of <strong>insulation</strong> became nearly 2.5 inches, and the air
circulation was more rapid because of lessened distance. Car B was
of the usual box type; car A had a box bunker with an insulated
bulkhead and a floor rack; car C was of the standard basket type.
Cars A and C received salt on the initial icing. They were neither
iced nor salted in transit on an 88-hour haul. Car B was iced once.
All contained from 400 to 500 cases of eggs. The three lower layers
were seven cases wide, spaced for air circulation, and the upper
layers were eight cases across. The average of all the thermometers
in the packages in various parts of car B showed that it was far
above cars A and C until the last day of the trip. An analysis of
temperatures in different locations shows, further, that the floor of
car B paralleled the top layer of car C. Car C did much the best
work of the three. Car A, having the rack and the insulated bulkhead,
but not the basket bunker, did not succeed in maintaining a
sufficiently rapid air circulation to cool the top layer more than 5°.
The packages on the floor, on the contrary, were exaggeratedly
chilled because of the pocketing of the cold air. The conclusion
follows that even with an openly stowed load, the car must be provided
with a basket bunker, an insulated bulkhead, a floor rack and
ample <strong>insulation</strong>, if our present loads are to be materially increased
with safety to the commodity.
Car C (Chart XIV) of the foregoing experiment, was again
used with a load of about 600 cases, stowed eight across. The ice
was salted at the start and 40 pounds was added on the second day.
Thermometers in the first, fourth, fifth and sixth layer packages give
an instructive picture of the rise in temperature with the height of
the load. Without salt, the fourth layer would be the stopping
point. The fifth layer cases around the walls of the car would
suffer if the weather were hot, if salt were not used. With the salt,
as this experiment shows, we can load five high with impunity, but
not six, because of damage to wall cases. A study of the chart shows
that the 40 pounds of salt added at the first icing station was
enough to cause a drop in temperature in all except the sixth layer
wall packages. Had another charge of 40 pounds been added the
next day, the rise shown in the lower layers would have been avoided
and the fourth and fifth layers would have continued to cool instead
of remaining practically stationary.
The investigation has convinced us that in the future ice and
salt will be used for more commodities than fresh meats, poultry
and fish. Indeed, it is the only way that we now see by which very
perishable small fruits can be transported in good condition through-
out the entire car. Of course, a definite routine for its application
must be worked out. The experiments for the summer just ending
have yielded much information. We hope that by the end of another
summer we can bring you specific instructions for a number of
commodities.