IMPROVEMENTS IN SHEATHING IRON AND STEEL SHIPS
Year: 1879

page_text: LETTERS PATENT to John Scoffern, of the Waterproof Paper Factory, Willesden
Junction, in the County of Middlesex, Bachelor of Medicine, for the Invention
of "IMPROVEMENTS IN SHEATHING IRON AND STEEL SHIPS."
Sealed the 4th July 1879, and dated the 28th January 1879.
PROVISIONAL SPECIFICATION left by the said John Scoffern at the Office
of the Commissioners of Patents on the 28th January 1879.
JOHN SCOFFERN, of the Waterproof Paper Factory, Willesden Junction, in the
County of Middlesex, Bachelor of Medecine. "IMPROVEMENTS IN SHEATHING IRON
AND STEEL SHIPS."
This Invention has for its object improvements in sheathing iron and steel
ships.
"
For the purpose of attaching sheathing slabs to iron and steel ships I cause metal
studs to be soldered with soft solder to the plates forming the skin of the ship.
Over these studs the sheathing slabs having corresponding holes formed in them
are applied.
The length of the studs is such that they do not project through the slabs, and
they receive screw nuts or caps.
The holes in the slabs are suitably formed to admit the said nuts or caps, which
thus serve to hold the slabs very securely in their places. The holes in the slabs
are afterwards plugged to complete a flush surface, and prevent the exposure of the
metal studs and their nuts or caps.
In place of using screw nuts or caps the studs may be of soft metal, and clenched
within the holes in the sheathing slabs.

page_text: -July-1879.-
JOHN SCOFFERN, of the Waterproof Paper Factory, Willesden Junction, in the
County of Middlesex, Bachelor of Medicine. "IMPROVEMENTS-IN-SHEATHING-IRON.
AND STEEL SHIPS."
This Invention has for its object improvements in sheathing iron and steel
ships.
For the purpose of attaching sheathing slabs to iron and steel ships I cause metal
studs to be soldered with soft solder to the plates forming the skin of the ship.
Over these studs the sheathing slabs having corresponding holes formed in them
are applied. The length of the studs is such that they do not project through the
slabs, and they receive screw nuts or caps.
The holes in the slabs are suitably formed to admit the said nuts or caps, which
thus serve to hold the slabs very securely in their places. The holes in the slabs
are afterwards plugged to complete a flush surface, and prevent the exposure of the
metal studs and their nuts or caps.
In place of using screw nuts or caps the studs may be of soft metal, and clenched
within the holes in the sheathing slabs.
Having thus given an outline of my Invention for a new process of sheathing
It is well
iron and steel ships, I now will give full working details of the same.
known that the bottoms of iron and steel ships need protection against not only
the chemical action of sea water, which rapidly corrodes the metal, but what is of
still greater importance against the adhesion of sea weed, barnacles, mussels, and
marine vegetables and animals generally. It is well known moreover that sheets
of copper or alloys of copper, which afford efficient protection to the bottoms of
wooden ships, cannot be used in the case of iron or steel ships, because of a galvanic
action which ensues, and which rapidly effects corrosion of the steel or iron. The
means of protection hitherto adopted may be classified under three general heads;
the following: (1.) Coats of paint or paint like semifluids laid on after the manner
of paint. (2.) Sheets of paper stuck on by adhesive cement up to a certain required
thickness. (3.) Slabs or panels of various materials screwed to the steel or iron
skin. I need not make any observations on classes 1 and 2, but as regards class 3
I will observe that a new and sound iron or steel bottom cannot be excavated ever
so little for the purpose of admitting screw attachment without weakening an iron
or steel bottom thus treated to an injurious extent. The strength of such an iron
or steel bottom after such treatment will be only equivalent to the strength of the
weakest part. My process of slab attachment does not involve-any-excavation-of-
the metallic skin, and does not set up any injurious galvanic action. It is appli-
cable to panels or slabs of any material the ship builder chooses to employ, and the
Invention relates to the mode of attachment only, and though I believe that the
materials of a thoroughly efficient slab are comprehended within a very limited
range, yet I claim no specific slab. Whatever the nature of the material used I
believe it must be capable of exfoliation, so that an animal or vegetable growth
deposited shall break away under the combined influence of moisture and motion
from its adhesion by the surface rupture of its base of attachment from underlying
material. This is exactly what happens to a copper sheathing when attached to a
wooden ship. The copper under the influence of water, especially sea water,
oxidises, and forms a layer of loosely adherent material, which, affording no hold
to marine, animal, and vegetable growths, they exfoliate and are carried away; the
opinion commonly entertained that it is the poisonous nature of the copper oxide
and salts which clears the bottom from marine growths is erroneous, as many have
satisfactorily demonstrated.

page_text: Amongst laminating materials I believe paper to be the best out of which to
manufacture slabs for ship sheathing purposes. It does not suffice to make the
slab directly from paper pulp, inasmuch as such a slab being nothing more than
very thick card board or mill board would be destroyed by the action of water in
an hour. The paper material must consist of sheets stuck together by some water-
proof cement and condensed by pressure. I do not specify any particular cement,
but will incidentally state that the material known by the names of "cupro-
ammonium paper" or "tissue," "cuproxyline" or "cuprolignine" is wholly efficient,
as is in like manner paper stuck together with tar, pitch, marine glue, and various
other hydrocarbonaceous adhesive materials.
Whatever the nature of the panel my mode of attachment is the following:-
I solder at convenient distances by means of soft solder my studs or stays, which
are of the following nature:-Each consists of a base (b) see Figure 1 of the
annexed Drawings, and a shaft or stem (8). The base affords solder attachment; the
shaft having a screw thread takes a collar of the following nature :—It is a circular
disc of iron or steel (see Figure 2) having a screw thread in the central hole admit-
ting the corresponding shaft. The two side holes are for the purpose of screwing
up by means of a tool constructed as follows:-It is of steel, tempered as ordinary
screw drivers are tempered, differing merely from an ordinary screw driver in the
respect that instead of terminating in a blunt edge fitting into a notch it is furnished
with two points fitting respectively into the pair of side holes already described as
drilled in the collar.
With regard to the number of shafts or stems upon a given area of ship's bottom,
this will vary according to the area, also according to the figure of the area, which
may vary from an_alinost plane surface through an infinity of curves, some concave
others convex, on the side to be sheathed or covered. It is impossible to specify
these curves, varying as they do for every ship. This infinite variation makes it
necessary that the panels shall be cut into convenient but variable shapes. As
regards the dimensions of panels for attachment by my process to a plane surface
they may vary to any extent without affecting my process. If the panels however
consist of laminated paper I find that panels of not more than twelve inch sided
squares are most convenient. Assuming a panel of this size to be employed then I
consider five spills or soldered shafts arranged as in Figure 3 to be sufficient.
If operating on a curve instead of a plane the number of shafts may be greater,
but this must always depend upon the abruptness of curve.
The first operation in my sheathing process consists in soldering to the ship's
bottoms the stays or studs. Assuming this done over a twelve inch sided square
area I take a panel of corresponding size and mark upon it the spots where holes
corresponding to the soldered on shafts are to be made. Each hole must be of the
general shape represented in Figure 4, and that part of the hole immediately corre-
sponding to the shaft must be somewhat larger than the shaft for the purpose of
permitting any slight adjustment by sliding of the panel. Before the panel is laid
in place I recommend that the iron or steel surface to be sheathed should previously
to the sheathing being laid on be smeared or painted. Tar alone or mixtures of tar
and pitch are appropriate. The panel is now adjusted, and upon each spill or shaft
a collar previously described is screwed up, not flush with the surface, but leaving
a slight excavation to be filled up. If the panel be of laminated paper I prefer to
fill it up with a disc of corresponding material cemented in by a portion of what-
ever adhesive substance may have been used in sticking the original sheets of paper
together to form a panel.
I have not stated any dimensions for the soldered shafts, but I recommend as
being perfectly efficient shafts of about an eighth of an inch diameter, each having
a base for solder attachment of about one half inch diameter. As to the length of
shaft it must be regulated by the thickness of panel. Panels of laminated paper I
consider best when about one fourth of an inch thick.
As I have already stated instead of shafts if iron or steel, shafts of soft metal,
such as pewter, may be substituted, and these instead of being fitted with screw

page_text: collars may be hammered, pressed, or otherwise splayed out.
In fact the shaft stays
may be made of any metal of necessary strength so long as the metal be of a sort
not productive of injurious galvanic action.
Moreover although soldered shafts of the peculiar description already stated have
_been_alone_described the necessities of certain curves render other forms of soft
_solder_attachments desirable, amongst which I specify the following:
:-
A flat surface of metal having at right angles two metallic slips, as represented in
section-in-Figure 5. The slips are passed through a corresponding slit in a panel
and flattened down right and left (see Figure 6).
The sheathing may be applied to the interior as well as to the exterior of an iron
or steel ship.
The term soft solder is sufficiently well understood by practical men to obviate
the need of any special definition. Several varieties exist all more or less applicable
to my purpose. I prefer however a special solder, consisting of the ordinary soft
solder with 3 per cent. of cadmium added.
I recommend the tool represented by Figure 7 to be used in soldering the studs
in their places.
The part from w to wis made of wood, and is the handle; t, t, represent an iron
pipe in section. The part c, c, corresponds to a perforated lump of copper ending in
a flat surface (circular), the diameter of circle equal to the diameter of the round
foot of the stem or shaft. The action of the tool is such that the copper being
heated and pressed down upon the foot of the shaft already prepared for soldering
the solder joint is established, whereupon the operator's thumb pressing upon
forces down a slender spill of iron upon the end of the shaft and at the same time
prizes away the hot copper lump, thus steadying the shaft, until the solder at its
base shall have consolidated. Pressure of the thumb being removed a spiral spring
concealed in the handle withdraws the steadying spill back into its original
place.
What I claim is,-
First. The attachment of sheathing to iron and steel ships by means of metal
studs fixed to the ship's side with soft solder.
Second. The means for attaching sheathing to iron and steel ships, substantially
as herein described.
In witness whereof, I, the said John Scoffern, have hereunto set my hand
and seal, this Twenty fourth day of July, in the year of our Lord One
thousand eight hundred and seventy nine.