Ship Damage 
Extensive cost studies on ship damage due 
to heavy seas are virtually non-existant. For 
the most part, the problem has been covered 
by such statements as, ''Throughout the war 
(WW II) the cost and time lost in the repair of 
ships damaged by heavy seas were as great as 
for battle damage." No doubt this estimate 
is in the right ballpark, and as such it presents 
the startling fact that we financed two equally 
expensive naval wars - the ''shooting'' war and 
the ''interface'' war. Even worse is the fact 
that the latter has never ceased, 
power vessels of over 500 gross tons register 
ed with the various governments of the world 
at the beginning of 1954, some 1, 021 suffered 
Of the 32,358 
heavy weather damage, 20 foundered and were 
a complete loss, and_another 976 were strand- 
ed during the year. 
Townsend da in a detailed study of for- 
ward bottom damage resulting from slamming 
in heavy seas to 141 American Flag vessels 
over a 26 month period, found that the total 
repair cost amounted to $3, 084, 905 averaging 
$21,879 per vessel, and requiring a total of 
581 days of repair. These figures represent 
only physical repair and do not reflect the 
cost of the vessel during repair or loss of 
earnings. It should also be emphasized that 
only the damage to shell plating and internal 
members in the forward bottom of the ship 
were considered. Any damage which may 
have been experienced by the rest of the ship, 
either due to slamming or to green water on 
the deck, is not included. 
Of some interest, in the context of this 
paper, is the fact that 56 percent of above 
damage occurred in the North Atlantic, 15 
percent in the North Pacific, 10 percent in 
the Western Atlantic, and 7 percent in the 
North East Pacific. Only 12 percent of the 
ships were damaged in the other parts of the 
world's oceans. Of course, a part of this is 
due to the position of the main trade routes 
rather than the geographical incident of 
heavy seas. 
233 
Since sea state cannot be controlled, the 
cost resulting from ship and cargo damage 
as well as fuel consumption can only be re- 
duced through better hull designs and ship 
routing. The Navy, realizing this, is using 
its Ship Routing Program, which was 
originally designed to reduce the cost 
of MSTS vessel operation, to route an 
increasing number of various fleet units, 
including submarines. The Program, 
developed by the Hydrographic Office and 
operated by the Navy since 1958, has made 
some 1637 individual routings (not to be con- 
fused with the number of ships routed) as of 
March 1961, As stated in the Introduction, 
this service has resulted in an appreciable 
transit time reduction by providing optimum 
routing through existing sea conditions. Re- 
liable figures for the reduction in ship and 
cargo damage resulting from this program 
do not exist, although various estimates 
indicate a significant reduction, Private 
shipping lines which, in their present heavily 
subsidized economic plight, can ill afford 
unnecessary damage and operating cost, have 
made only token use of this service although 
it is offered by several private concerns. 
WAVE HEIGHT OBSERVATIONS 
AND FORECASTING 
The Sea State Code 
The term sea state, as generally used, 
may be defined as the average height of the 
highest one-third of the waves observed in 
a wave train referred to a numerical code 
which covers an increasing range of such 
heights (see Table II). As shown in Table 
III the code may also be applied to swell con- 
ditions, but used alone, as it usually is, it 
makes no distinction between sea and swell. 
In addition the code gives no idea of the 
stage of development or decay of the wave 
spectrum, nor does it allude to the distri- 
bution of periods. 
