The morning news. [volume] (Savannah, Ga.) 1887-1900, 1899-07-16
BASIN FOR TESTING wARsHIPs.
New Cruisers to BE Designed After
Experiments Win Models.

Experiments With Models.
Washington, July 11.-For over fifteen
years Rear Admiral Hichborn, chief of
the construction bureau Of the navy. has
been endeavoring TO secure the building of
an experimental naval basin. He was sent
abroad by Secretary Chandler as far back
as 1884 to see what improvements had been
devised in shipbuildng by other countries,
and came back with the idea for this in
his brain. But it was not until towards
the close of the Fifty-fourth Congress that
he was able to secure an appropriation of
the necessary $50, 900 to put his plans into
operation.
The need of such tanks has been recog-
nized abroad for a sill longer time but the
governments have hesitated to so into it
sufficiently 10 attain the best results. Mr.
William Denny, the most progressive of
the Scoth builders, and the owner of the
only private basin in the word, said re-
Gently, in discussing the question: "Of all
the problems about a steamship, the only
one incapable of being solved at the pres
ent moment by priori method are those
relating to speed and power. No ability
and no training will enable even the most
skiIful naval architect TO overcome the
want of an experimental tank in coping
with these questions.
1t is TO find out this ideal hul,-the one
that win attain the maximum result Of
speed, of carrying power or of whatever
other quality that may be desired-that
the United States has erected, after many
years of solicitation on the part Of the
Of
enormous basin
The basin was authorized by Congress
two years ago, and already partial expert
ments have been made with a model of
the Iowa, and the basin has been proved
10 be thoroughly accurate in its predictions
in regard to speed. Very soon exhaustive
experiments viii be begun to determine
the best shapes for the hulls Of the new
warships authorized last March.
The Eank has a length of 500 feet ond
a.ong each of its long sides is laid a rail-
way on which runs a towing carriage"
which extends like a bridge over the tauR
from side to side.
When the great weight OF the carriage
twenty-five tOns) is taken into considera-
ton as well as the rapidly with which
it moves and the perfect control under
which it operates at ali times, 1t will be
easily understood that the whole process
of operation is little short of marvellous.
In fact, the motor carriage of the model
basin is a mechanical and electrical won,
der and a thing almost entirely unique.
On il is a complicated piece of machin-
cry worked by the Ward-LeOnard system
of electrical control, capable of driving
the carriage along the rails at twenty-five
miles an hour within 200 feet of the start
ing pace.
Hung to this bridge carriage. by means
OF a dynamOmeter will be the various
W 81 is tome To
loaded so as 10 float the exact proportion
ate Depth designed for the ship. As the
carriage sweeps along, towing the model
the dynamometer viii register the resist
ance of the water to that particular form
of bow at each speed from one knot IN
hour up TO thirty. If it is found that the
resistance is greater than it should be, the
model will be taken back to the carpen-
tcring establishment attached 10 the basin
and trimmed down or built out, as may be
thought best. and then tried again and
again until the very best shape for The
purpose intended is resolved upon.
When one is finally adopted, the resist
ance OF the water to its progress at various
speeds will be carefully noted, and from
this it viii be very simple to calculate the
exact power of the engines required TO
give the ship, when built, the greatest
speed Hereafter there will be no danger
that the engines will be found too weak for
and strong, thus losing weight that might
better be devoted to some other part of the
vessel.
There IS one especial advantage in the
high speed that can be attained I'm the
tank which layman will necessarily over
look It results from the tendency of
ship to bore downwards in the wafer.
The faster she goes the deeper she will
bore, the more of her will be submerged
and the larger wil be her displacement
For instance, the coast defense vessel
Monterey, when running at fun speed.
plunges her entire bow under waller, thus
Offering a much greater surface 10 the
water and increasing the resistance 10 her
passage. 1t is evident that portions of the
bow which are well out of wafer at ten
knols-the maximum speed attainable In
any of the European tanks-wil be sub
merged entirely at twenty knots, and that
as much care should be taken TO design
80 as TO offer the least resistance of the
upper portion to the wafer as Is taken with
the lower portions, which are always SUBJ
merged. Yet never In the history of the
" orld has it been possible to ascertain the
best shape for them in advance Of actual
test after The ship has been completed,
when, of course, it is too late for alter
lions.
Objections may be made that the tank
offers, after all, only smooth water facil-
lilies and will not give evidence as to