Democratic Northwest and Henry County news. [volume] (Napoleon, O. [Ohio]) 1894-1905, 1894-09-13
DOCTORING SHIPS.
PARASITES THAT SEND OCEAN YES
sells TO THE HOSPITAL.

Been Found-The Old and the New Man
ners Of Construction-someth About
Drydocls and Their Uses.
The sea is grand and yet treacher-
ous mother to the thousands of ships
that sail over its broad expanse, and aft
er buffeting with its storms the ships
must go to their hospital for repairs
This hospital is the drydock, and the
doctors are the army of careful work
men who look over carefully and repair
every faulty seam or broken rivet.
Salt water is teeming with parasites
Of plant and animal life that cling to
the bottoms Of ships, eat slowly yet
surely through wood and iron alike. or
rust it away, while they act as a check
on the speed by vastly increasing the
resistance and friction of the water
against the ship. The ''gods of the
storms see everywhere" and pick out
each weak seam or faulty rivet and
slowly and surely eat into the vitals Of
the ship, SO that every few months 1t
becomes necessary to examine and re-
pair the vessel. To do this she must
come out Of the water. The drydock is
Just great box of wood, iron and stone,
connecting with the sea by great gate
way. When the ship is ready to enter,
the gate is shut and the water all pump
ed out; then the workmen, with prao-
ticed skill, place the blocks at the bot
tom Of the dock for the keel to rest
upon, taking the dimensions from the
plans and drawings of the vessel. These
In place, the dock is flooded again, the
gate opened, and the ship hauled in
The gate is now closed again, and while
the water is slowly pumped out and the
ship settles down the dockers pull her
this way or that until she rests evenly
on the keel blocks. Then shores, or
heavy wooden beams, are braced from
the sides Of the dock to the sides of the
ship, and as the water is pumped away
the ship stands "high and dry" ver-
liable fish out Of water" the bottom,
which was below the water line, cover
ed with seaweeds and parasites that
hide the defects they have caused.
Then the workmen scrape and scour
the unwelcome barnacles and grass
away, the seams and rivets are all ex-
Rmined and repaired, fresh coat Of
paint goes on again, and as the dock is
again flooded the ship rises from her
hospital bed, and the wooden supports
are knocked away until she floats out to
sea again, healthy and strong" to
battle with the wind and sea and the
enemies of the flag she proudly flies.
When wood was used almost exclu-
sively in building ships, very easy and
convenient means was found to protect
the under water portions Of the ship
from the insidious attacks of barnacles
and parasites Of plant and animal life.
This was done by covering the whole
bottom Of the ship with a plating of
thin copper, for the galvanic action of
the salt water upon the copper was to
convert the ship and sea into vast bat
terry, where the copper became the mega
tive pole and was slowly yet constantly
eaten away, the particles, as they fell,
taking with them the barnacles and sea-
weed as fast as they formed on the
ship, thus keeping the ships bottom
and sides always clean, so that the speed
was not cut down by dragging the bar
nacles and yards of seaweed through the
water. Yet even then the copper need
ed repairs; faulty timbers rotted and
crumbled away, SO that every few years
the ship had to go into drydock and be
thoroughly overhauled, each faulty tim
ber replaced and rusty bolt repaired un-
til no loophole was left for the sea tc
work upon.
But with the advent of iron in the
building of ships the old means failed,
for where copper was placed over iron
the iron became the negative pole of the
great battery and was eaten away quick
| ly, riddling the bottom Of the ship with
many leaks Many devices were tried
the under water portions Of the vessels
were covered with q waterproof layer o.
wood, which was then coppered as be-
fore, but wherever there was any me-
tallic connection between the copper
and iron the whole force of the battery
acted there, and holes were eaten in un
expected and inaccessible places bring
ing in an element of uncertainty anG
enforcing great care in "sheathing" the
vessels, as the coating of wood is called,
and the ships still had to go more otter
than ever to the drydock.
Then the various methods Of painting
the bottoms with protective paints have
been tried and are used in all Of the
cruisers of our navy. The skill of hun
dreds Of chemists has been exerted K
find paint that would act as the cop
per does and throw off the barnacles ant
seaweed. Great prizes have been offer
ed, and fortune awaits the successful
discoverer of such coating for ships
yet so far none has been discovered tina
acts completely, and the iron and stee
ships which start from port with fresh
ly painted sides and bottoms return in
few months coated with barnacles ant
sea weed, which, as it trails in the wa
ter, very materially cuts down the speet
and power of the ship. Then she mus
be put in the dry dock and scrubbed ant
scraped and repainted. Still worse thai
the barnacles and the seaweed is tn
water itself when it finds an entrance
be it ever so small, through the pain
to the steel below. Slowly but surel.
it rusts out a little pit, which extend
sometimes almost through the plate be
fore the paint scale drops off and dis
closes the defect, which can even thel
only be seen by putting the ship in DIR.
dock and examining every square foo
, of her bottom plating.
This all shows how necessary it is fo
the ships to go to their hospital" ant
how careful her doctors should be
} for millions of dollars worth of propert,