Chapter 2: Shipping Costs to the Far East
Hosford International, Inc. of Erie, Pennsylvania is an
international freight forwarding company that provides services to
firms that export and import products worldwide. The company assists
its clients in preparing documentation such as letters of credit,
which spell out the terms of payment, as well as in arranging the
scheduling and transportation of freight shipments using the most
cost-efficient methods of shipment.
Actual shipping costs will, of course, vary according to such
factors as the mode of transportation, the distance over which the
cargo must be shipped, and the actual freight line chosen to
transport the cargo. Approximately half of the overseas shipments of
Hosford International's clients are transported by air, while
the remainder is transported by ship.
In addition, some ocean freight lines base their shipping fees on
how much space (out of a standard-sized full container) is taken up
by the cargo. A full container's capacity is generally 1800
cubic feet, or in the language of the trade, 45 "measures," where one
"measure" is equal to 40 cubic feet. One particular ocean freight
shipping company,
Maersk
Line, has quoted the following costs as of March 1994 for
shipping machinery from Baltimore to Hong Kong:
$332 per measure (i.e., per 40 cubic feet) of cargo, or
$4690 for a full container of 45 measures (i.e., 1800 cubic feet)
A company with a small volume of machinery to ship might choose to
pay the per-measure cost, but a company with a much larger freight
volume could lower its average shipping costs per measure by renting
a full container. For example, the average shipping cost per measure
of cargo remains fixed at $332 up to the point where the cargo load
is 14.13 measures ($4690/$332), but begins to decline thereafter,
reaching a minimum of $104.22 per measure at a full load of 45
measures. Thus, for all cargo loads ranging from 14.13 measures up to
a full load of 45 measures, the average shipping cost per measure of
cargo is given by the equation

where Y is the average shipping cost in dollars per measure and X
is the volume of cargo in measures (or fractions of measures).

For all cargo volumes over 14.13 measures, up to a full load,
average shipping costs decline, but at a diminishing rate. The rate
at which average shipping costs decline as the volume of cargo
increases is given by the derivative of the function Y with respect
to cargo volume X:

Such patterns in freight shipping costs have practical
implications for a company that is in the process of shipping a final
product overseas. Knowing the rate at which average shipping costs
decline with cargo volume will help in making better financial
decisions. For more information on freight forwarding see
www.forwarders.com.
What Would You Do?
1. Suppose that a shipping line charges the following rates for
shipping freight from Baltimore to London, England:
- $261 per measure of cargo
- $5079 per full container of 45 measures
(a) Formulate a general guideline for when to choose the
per-measure cost or the full container cost, and justify with
calculations.
(b) Construct a function that reflects the average
shipping cost per measure for this situation, and sketch its graph on the appropriate
domain.
(c) At which shipment level is it more beneficial in terms of cost
to increase the shipment size by one measure at 25 measures or at
35 measures? Explain your reasoning.
2. Suppose you have more than enough cargo to fill one
full load, but not enough to fill two loads. How would you use the
cost functions to decide whether to make one shipment first or
ship all of your goods at the same time?