The Neihart herald. [volume] (Neihart, Mont.) 1890-1901, 1897-12-18
PLATING SHIPS, HuLLs.
iron Ships to Be Placed In an Electric
Bath.

Bath.
A new departure in the sheathing or
vessels Is to be undertaken in TINS
country, and the future cruisers ana
battleships made for the United States
navy will probably be copper-sheatneus
according to the new process of cleo
tro-plating. Experiments have been
going OF for many years to electro
plate with copper the hulls of iron or
steam vessels, and the results OBJ
tanned now justify the general adop-
ton of a process of protection that IAN
be called purely American. An cleo
trio plant has been established at Jer-
sey City by the Ship Copper-Plating
Company, and the seagoing tug ASSIST
ance was treated to the new process as
an experiment. She has stood the test
so well that, after a year, she has a
hull nearly as free from all defects
caused by c%orrosion and sea animals
as when first launched.
Copper sheathing has been adopted
by s~hip-builders of all the leading
countries for years, and it has always
proved the best protection to the hulls
that could be devised, but rust and r
rosion find it's way between the cop
per plates in time, and starts up open
ings hat eventually destroy the ships
bottom or necessitates the costly work
of resheathing it.
The old way was to plate the bottom
Of the ship carefully from stem to stern
with stout wood, and then coat this
with sheath copper, but the new meth
cd is to place the vessel in a bath of
copper sulphate, into which an electric
current is passed. Liquid-tight COM
partments are made to fit firmly upon
the sides and bottom of the hull, and
when filed with a solution of the cop
per the four anodes are placed through
an opening in the top. These consti-
tute the positive pole, n the iron
hull acts as the negative. A film or
copper without seams or breaks gradu-
ally forms on the bottom of the ship,
and in forty-eight hours this air-tight
sheathing is one-sixteenth of an inch
thick. The sheathing fits SO tightly
to the hull that it cannot be removed
without cutting into it with sharp in
struments, and even then it has be-
come so welded to the iron that he
two cannot always be separated.
The value of this unbroken surface
of copper plating can be readily UNDER
stood when some of the injuries to the
bottom of iron vessels are examined.
The old method of copper sheathing
added so much to the weight of the
vessels that the naval advisory board
in 1882 refused to have the hulls OF
the Chicago, Boston, Atlanta and Dol
phin sheathed. In the case of the Chi
cago it was estimated that 255 tons
would be added to the weight of the
vessel, and 100 tons would be added to
both the Boston and Atlanta. Pur-
suing this same policy of keeping the
vessels light and buoyant on the water,
and thereby gaining additional speed,
the department refused to have any OF
the subsequent war vessels copper
sheathed. AS a result me of our war
vessels are s%heathed, although a good
r percentage of the ships of the English,
French, German and Russian navies
have their bottoms protected in this
way. BY the new process of electro
plating the weight added to the YES
sells amounts only to 2.S5 pounds to the
square foot.-Philadelphia Times.