Brezk-íslenzk viðskipti - 01.05.1947, Page 24

BRETLAND OG ISLAND, Maí, 1947
Aluminium Alloys in Fishing Trawlers
By Dr. E. G. WEST
(Technical Director, the Aluminium Development Association)
The great difference between the top market price for fish and the price paid for
fish suitable only for conversion into fertilizer has encouraged trawler owners
continually to investigate new methods of preserving the catch. The insulation
of trawler fish rooms assisted greatly in improving the condition in which fish
reached the market, but recently the problem has been successfully attacked from
another angle.
RECENT reports have appeared in
the Press in this country, in
America and on the Continent,
to the effect that aluminium ships are
about to be, or are in fact being, built.
These reports, whilst perhaps a little
premature, certainly indicate that
there is a tremendous revival in
interest in the use of aluminium alloys
for ships, and this revival may be
traced partly to the facts that
aluminium is now free from war-time
controls which restricted its use to
aircraft, and that it is the only
commercial metal available, in quan-
tity, at a lower price than before the
war.
The idea of applying aluminium to
marine craft is by no means new, for
one of the earliest experiments in its
use took place over 50 years ago when
Sir Alfred Yarrow built a 60-ft.
torpedo boat for the French Navy.
This vessel was less than 10 tons
lifting weight and made over 20
knots; but unfortunately this early
experiment was unsuccessful as the
aluminium - copper alloy employed
proved unsuitable for service in sea-
water. However, developments in
the last 20 years have demonstrated
beyond doubt that certain other
aluminium alloys possess distinct
advantages over many of the more
conventional materials commonly em-
ployed, not oniy for small boats but
also for structural components of
large ships. It is perhaps convenient
first to summarise the advantages
claimed by aluminium alloys for
marine purposes, and this may be
followed by some notes of past
experience and a brief discussion of
the more technical aspects which are
now receiving urgent and detailed
consideration.
•
ADVANTAGES OF
ALUMINIUM ALLOYS FOR
MARINE PURPOSES
Reference may be made to the
literature supplied by the aluminium
industry for details of the various
properties and characteristics of
aluminium and its alloys, but those
of immediate interest to the ship-
owner, the naval architect and the
shipbuilder may be summarised as
follows:
1. Low Weight.—The density of
aluminium and its alloys is about one-
third that of steel, with the result that
considerable savings in weight are
possible, a general figure being 40 to
60 per cent. reduction compared with
steel.
2. Freedom from Rusting and
High Resistance to Marine Cor-
rosion.—It is not generally apprecia-
ted that aluminium and its alloys
possess greater inherent resistance to
corrosion by sea-water than do the
0 Fish Room in Aluminium
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