New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1898-04-17
BOTTOMS EASILY FOULED.
TROUBLE CAUSED BY MARINE GROWTHS
ON WARSIIIPS.
Cop,,t,p surATuING TIE ONLY SUCCESSFUL
PLAN OF AVOIDING THANKING IA
pIpITY OF THE GROWTIIS.

The stateme1; made n few days ago that ''c
,o.ilo-sbin Massachusetts was at present IN
capable Of attaining the speed necessary loi ''0
fivina squadron. owing 10 the foulleSS oi hV'
bottom has called attention anew I" the pio'-
lem of keeping the huls of WarShlps cea"' anu
has given new force to the arguments III l"No'
OF the use of copper sheathnS. The amount VI
The marine growths of various KINDS WhIch az
cu71,ulate upon Il ships bottom would seem al
most incredible to the ordinary uhinloriheu GU
,zon An idea of the rapidity with which they
gather may be gained from two examples take"
at random from one Of the Naval reports Dur
In six months in 1857 the bottom OF the "''
FRO, vessel Alert was found to have become IN
crrsted with twelve tons of hainacles' n III
tie over two months after this had been
tborouch,v cleaned off a diver again inspected
.hs bottom and reported that it was aireadH
covered with "A strong new growth. III i'N'
flo Ranger also an iron vessel. was locked
ofier y few months voyage. in order to he
cleaned at the Mare Island Navy YARD, near
San Francisco She is said to have prcschie"
o strange appearance as she came up the mar
bor Along her water-line was a thick grown
Of bright green seagrass. varying from t."
inches TO a foot in length. Besides inns great
stringers and lunches Of kelp-the large spcc'es
of eeaweed common on the racine c"as'S ~
both North and South Amerca-Were 'ral""s
ALONGSIDE and astern. Some OF these CLUSTERS
were six feet in length. The water III the Marc
Island Straits is nearly fresh. and consequently
most Of Che kelp soon dropped off. but when the
shin was locked she found to he coated
with barnacles. in many places to the depth
Of an inch and a half, and there was dehse
growth Of marine vegetation, with clusters Oh
mussels, to an average depth Of four inches
The total weight of the entire mass accumu-
lated was computed at twelve tons
This gives fair idea Of the kind OF growth
which fouls a ships hull. In addition to the
varieties mentioned coral also attaches HSch
70 the bottom The barnacles are Of two kinds
the goose and the acorn barnaclc. They dincr
IN that the former fastens itself to the metal
nv means of a stem while the latter adhercs
directly and closely But barnacles and mus
sells are not the only shellfish which assist in
fouling ships All the lime formations OF sea
water are more or less troublesome. Large
oysters have been found adherlng to the hulls
Of iron vessels after a few months cruising In
comparatively warm waters. The higher the
temperature Of the sea the more rapidly does
the fouling process go on, fact when Is pro'cu
constantly 10y the difference In that respect OBJ
served by the transatlantic liners. according to
whether they follow the northern or the south
route
Any known substance will begin to accumu-
late a marine growth when submerged In sea
water and the various kinds Of anti-f"ung
paint which have been tried serve only to re-
tard the evil more or less: they do not succeed
in preventing ii. Among the many expert
ments which have been made with view 10
avoiding fouling, copper sheathng has been
found to be the only thoroughly satisfactory
means Of accomplishing this end Copper is
peculiarly suitable, because. although in com
mon with other materials 1t is subject to &C
crctions Of marine matter, IL is "A metal which
corrodes very readily in sea-watcr. The verdgris
resulting from this corTOsiOn has little power Of
adherence to the metal and falls off powder
upon the application Of the most trifling force
such as is furnished by the wash Of the waves
and the movement Of the ship through the
water As the verdgris drops off il carries
with it the growth which is just starting and
the vessels bottom is thus continually kept
bright and clean. The only occasions on which
copper shcathcd ships have been known to be
come foul have been when they remained
anchored for some time in warm water. but as
soon as they were well under way the marin"
growths were soon swept off. a Kind Of brass
called Mun.z metal and zinc have also been tried
for sheathng, but they have proved inferior
to pure copper.
The extent to which fouling reduces vessels
speed is IN many instances very great. by the
increased resistance which the roughncss causes
in the passage through the water the speed IL
sometimes lesscned onc-third In the case Of
the Massachusetts recently it was said that
she dropped from seventeen to thirteen knots
Oh account Of the condition Of her hun. 1t has