The sun., 1893-11-23
TRIPLE-SCREW PROPULSION
Its Advantages Both for War Vessels and
the Merchant Mnrine,

WAsHINoToN. Nov. 22.-One result OF the re-
| markable success OF the Columbia In her trial
trip will probably be q very great extension Of
the use Of three propellers instead OF two in
war vessels. and very likely also In some fast
merchant ships.
1t was not. indeed. the use OF three screws
instead Of two that gave the Columbia her re-
markable speed record. II the power OF her
big engines could have been applied to two
screws on that trial It would perhaps have
achieved speed as great and possibly even
little greater But the use Of three propellers
has certain other advantages OF much value.
and since 1t has been shown that splendid
speed may be made with three. any doubt as,
to their usefulness as q whole must vanish.
Triple propellers were we'll known In foreign
navles before they were introduced into our
own. One OF the most fam Gus vessels to which
they had been applied was the great French
cruiser Dupuy dc LONE. OF 0.297 tons dis
placement. which received them years ago.
Again. various Italian torpedo cruisers had
been fitted out with them. including the
Tripoli. the Montebello. and the MonzAmbano.
Finally. the splendid and yery fast German
cruiser Kaiserin Augusta, which was present
In New York at the international review last
spring. had them at that time.
Thus 1t 10 not at all an experiment that has
been tried on the Columbia. but we'll -estAb-
lished system OF propulsion. A further justin
cation Of Its adoption here was the fact that
the proper manner OF placing the screws had
been fully determinsd By European practlce
The French made all the necessary experl-
ments with their steam launch CArpe. and
they ascertained that II all three propsllers
were placed abreast. the centre one would not
do so much work As 1t should. since the water
flowing to It was intsrfered with by the two
aNI AEuNU L.. 4 4 4
the centre propeler was placed aft OF the other
two. and the same arrangement was followed
In the Columbia where 1t 10 fifteen feet aft.
Again. further to secure the greatest efficiency
for all three screws In the Dupuy de LONE
they were not even placed In the same horizon
tai line but the two side ones were higher.
WITH 4 view 20 prevent their race from inInr-
iGis arrangement Was also S' aSopted rGP'f IN sSc
Columbia. improvements. OF course. being
In the Colam 6ia the MID H de p4opelleris about
cline: .lg6iiS d9ERwsrd, i, %Rio ,ssl. fs@ on on
from being Affected Ss ihsIss sun mOtSS! diSSt
blades while thsy have only three each
6s ssG6osr sG5S RarsS snd In water thrOSn az
y is said. g about ons,tsath' fho1 ma. a.
GLHH'nssR6 LH bs,0 lhs SSluH9lp was designed
improvements over triple screws a. nseI
elsewhere should bs passed 10 the credit OF
our englnecr!ug authorities. Ii i believed
also thai the me shape ot the Coiunibia's hHii
assists tho iree run OF the water along 10 The
screws me middle propeller is rlaced ia tbs
mldshlp me. close down to the Keel aud
lust forward Of the rudder, while the others
are l"ratei above. one under each counter
ana, as has ALREADY been Indicated. forward Of
the stern post The MessTs. tramp bullI tho
engines oi the Columbia strictly on tile de-
signs OF hisI Engineer Melville
The introduction OF the trlpls propuIsion
system IN Europe had come al a REGULARLY
tqrtqhatg time Tor our purpose. Ii Was de-
unprec ell sntsd in our navy. Az agEregafs ~
A. least 2l,OuO Indicated hoI pow eT Was fiGed
upon. or more than double that Of any vessel |
itself In the fact that IL was Ysry doubtful |
Nðsr shAftinR heaVT enough could be pro-