RECENT ECONOMIC TRENDS: Demand forships, April 1959
| Author | J. R. Parkinson |
| Published date | 01 November 1960 |
| Date | 01 November 1960 |
| DOI | http://doi.org/10.1111/j.1467-9485.1960.tb00139.x |
RECENT ECONOMIC TRENDS
DEMAND
FOR
SHIPS,
APRIL
1959
THE
demand for ships may
be
considered to depend on three factors:
the amount of tonnage scrapped or lost, the need to expand carrying
capacity when world seaborne trade is increasing (or contract it when
the reverse applies), and the effectiveness of shipping in carrying avail-
able cargoes. The list
is
not,
of
course, complete, and the three
factors are not independent of one another as we shall see, but it
provides a useful framework for considering how the demand for
ships
is
likely to develop in future years.
It
is
the purpose of this
note to set out how
it
appeared reasonable to view the situation in
April
1959,
starting with estimates of the tonnage that it might be
expected would be withdrawn from service
on
the basis of past
experience.
Wastage rates
In
a previous study,’ estimates were made of wastage rates in the
period
1885-1914
(supplemented by data for
1860-1884)
and
for
the
inter-war period; some post-war figures were also given for comparison
which have been brought up-to-date
for
the purposes of the present
study. Broadly speaking it appears from these figures that both before
the first world war and in the interwar period ships lasted on the
average about
33
years. There was a wide dispersion about this
average figure but there appears to
be
little evidence of any striking
change in the longevity of ships over almost a century of experience.
This
is
not
to
say that the longevity of ships
is
independent
of
country
of
ownership
or
economic conditions, to mention only some
obvious variables: and it appears’ also that non-tanker vessels have
an appreciably longer
life
than tanker vessels
so
far
as
can be
judged from what has happened in the past five
years,
although no
account could be taken
of
this
in
arriving at earlier assessments
of
wastage rates.
Quite apart from the interpretation of data calculated for past
periods,
it
is
very difficult to judge how far previous experience
is
relevant to present or future conditions. It
is
sometimes maintained
that technical progress moves more rapidly now than it did
50
to
100
years ago, and that
in
consequence obsolescence occurs rather earlier
in the life of capital instruments than formerly. Again, durability
may change as new designs are introduced, or altered economic con-
1
See
J.
R.
Parkinson,
‘Ship
Wastage Rates
’.
Journal
of
the
Royn!
Stotisticnl
Sociery,
Series
A
(General),
Vol.
120,
Part
I,
1957
(pp.
71-83).
145
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