ASHRAE Journal - November 2020 - 62

REFRIGERATION APPLICATIONS
COLUMN

Andy Pearson

In Transit
BY ANDY PEARSON, PH.D., C.ENG., FELLOW ASHRAE

One subject has, until now, been neglected in the columns I have written for ASHRAE
Journal despite the fact that it is one of the oldest applications of refrigeration and has
been developed over the last two centuries into a technology of extreme sophistication
and global signiﬁcance.

CREDIT: EVRENKALINBACAK/ISTOCK

The subject is transport refrigeration and the hiswith the introduction of intermodal transport; the rise of
tory of this technology began with Thomas Moore's
the shipping container and the development of compact
icebox, which he called a "refrigerator," patented in
and robust refrigeration units. The technology embed1803. Moore used his box, a wooden chest containing
ded in these wonders of modern engineering spans a
an iron tub, to carry butter on horseback to market,
wide array of requirements. Of course the systems need
using ice packed around the tub to provide the coolto be extremely reliable. They may be at sea for months
ing. He estimated that only four or ﬁve trips to market
without any maintenance intervention and the value
were required to pay back the capital investment in his
of the container contents-far in excess of the value of
system, given the massive premium that he was able to
the container-is totally dependent on the refrigeration
charge for his butter because of the excellent condition
unit's continued operation. They also need to be rugged.
in which it was presented to the purchasing public.
Operation must be assured over a wide range of condiOver the next century these mobile refrigtions ranging from storms at sea to bumpy
erators got bigger, including several variants
dirt tracks far from paved roads and in
of railcars using packed ice or salt-ice mixambients from arctic to equatorial, sometures. These iced railcars enabled the mastimes in the same voyage. Flexibility is
sive growth of Chicago as a meatpacking cenrequired. The refrigeration unit is electriter since cattle could be transported live from Luxury or essential?
cally driven with power usually supplied
all over the Midwest, butchered and dressed
by an onboard gen-set or from an external
at the Chicago stockyards and then shipped across the
electrical supply point. Many units can be plumbed into
Eastern seaboard. Further south the development of
a cooling water system to ensure continued operation if
Georgia as the Peach State was largely facilitated by iced
they are stowed below decks on a long sea voyage where
railcars distributing the fruit harvest over thousands
their air-cooled condenser would be inoperable. The
of miles. In California, the Continental Fruit Express
units also have to ﬂex between carrying fresh and frozen
and the Paciﬁc Fruit Express operated many thousands
product, sometimes in the same shipment, and the load
of these "reefers" to bring fruit to the east. By the end
might also require humidity control or ventilation.
th
of the 19 century well over a million tons a year of ice
These modern marvels have transformed the cold
was used for these refrigerated rail transports. Similar
chain. Long range food shipment is sometimes cast as a
developments occurred in Russia where food was
luxury item, enabling us to enjoy fresh, exotic produce
shipped equally long distances, but they were less comout of season. However, it is much more than this and is
mon in Europe where shorter journey times enabled
an essential part of the modern, urban,
growers to get by without so much ice assistance.
industrialized world. Urban growth over
Although a mechanically refrigerated reefer was demthe next 30 years will ensure it remains a
onstrated in 1888, the use of ice persisted until the late
critical service in reducing food wastage
1950s when mechanical cooling units were introduced
and ensuring security of supply for the https://bit.ly/309ZpBE
Rate this Column
more widely. The last ice-cooled reefers were taken out
foreseeable future.
Andy Pearson, Ph.D., C.Eng., is group managing director at Star Refrigeration in Glasgow, UK.
of service in the USA in the early 1970s. This coincided
62

ASHRAE JOURNAL

ashrae.org

N OVEM BER 2020

https://www.bit.ly/309ZpBE https://www.ashrae.org/

ASHRAE Journal - November 2020

Table of Contents for the Digital Edition of ASHRAE Journal - November 2020