IMPROVEMENTS IN SEA-GOING VESSELS
Year: 1882

page_text: "
LETTERS PATENT to John Henry Johnson of 47. Lincolns Inn Fields in the
County of Middlesex, Gentleman, for an Invention of "IMPROVEMENTS IN
SEA-GOING VESSELS communicated to him from Daniel Ammen a person
resident at Beltsville Prince George's County and State of Maryland in the
United States of America.
PROVISIONAL SPECIFICATION left by the said John Henry Johnson at
the Office of the Commissioners of Patents on the 12th December 1882.
"
JOHN HENRY JOHNSON of 47 Lincolns Inn Fields in the County of Middlesex
Gentleman "IMPROVEMENTS IN SEA GOING VESSELS a communication to me
from abroad by Daniel Ammen of Beltsville, Prince George's 'County and State
of Maryland, in the United States of America.
The object of the Invention, is to produce a vessel of very great strength of
construction, of great handiness in movement, and capable of being kept afloat, and
even temporarily repaired at sea, should a hole of considerable size be made in the
bottom, by whatever cause.
The vessel is formed transversely on the semi-conjugates of ellipses, the curves
of which are prolonged to meet at the sides in the plane common to both ellipses,
the spaces between the true ellipses, and the prolongations of the curves before
mentioned, may be filled with sponsoning, should the purpose of the construction,
be favored by a sponsoning-There are also longitudinal bulkheads-Longitudinally
considered, the girders, upon which the vessel is built, converge following the
curves of a parabola, the keel also following the line of a parabola, for any desired
proportionate length of the keel, and terminating in the plane of the greatest Beam.
The point towards which these parabolic curves are projected, may be at some
distance beyond the terminals of the bow and stern of the vessel, and the bow and
stern fashioned, and fastened as desired-The after body is constructed on the
same principle as is the fore body, namely the converging of the girders on
parabolic curves-Open trusswork to support the rudder post may be employed

page_text: in the construction, the object of which is to support the rudder post and at the
same time to avoid the lateral pressure against the action of the rudder, when
employed in turning the vessel as rapidly as possible.
Throughout the vessel, transverse bulkheads are placed where practicable, at
distances apart, equal to the half sum of the transverse and vertical diameters, of
the interior shell of the vessel.
For the prevention of sinking should a considerable hole from any cause be made
in the bottom, it is arranged to close all of the apertures through the deck and
parts over the fire room, by means of air tight scuttles, or hatches, and to bulkhead
- off the fire room and any portion of the engine room desired, from the other
portions of the interior of the vessel, bracing the bulkheads sufficiently to resist
the pressure caused by operating a steam air pump, having the necessary pipes
attached, through which the various compartments, other than the fire room, or
part partitioned off by bulkheads, shall be filled with compressed air, and held
under a pressure, slightly in excess of that of a column of water having a height
equivalent to the draught of the vessel.
In order to pass from the fire room to the other compartments double doors and
an air lock of the size desired, are to be made, and the doors are provided with
suitable gaskets to make them air tight, when secured.
The chamber is to be provided with an air valve, opening into an apartment
having air pressure, by operating which the apartments can be brought into
equilibrium, as to air pressure.after securing the outer door.
Pressure gauges can be fitted in the fire room, from all the compartments, and
thus any irregularity, or defective condition, would be brought to light and could
be remedied.
To effect this object, and for increased security, all the scuttles through the
various bulkheads, should have double faces, fitted with gum gaskets, operated in
common, with a lever or otherwise, the object being to secure a tight-joint,
whether the pressure be on the one side of the bulkhead, or on the other.
Should a hole be made through one or both bottoms of the vessel, so long as
the air pressure is equal or greater, than the hydrostatic pressure, no water will
enter; however large the hole may be, and repairs can be effected unembarrassed
by water, by means of mats, planks, stanchions and, wedges, so that were
longer possible, or desirable, to maintain an air pressure,. the leak, would be
inconsiderable, and controllable by pumping
it no
Should a hole be made above the floor at any given height, and below the water
line on the vessel, there would be an inflow, proportioned to the hydrostatic
pressure, impeded more or less, by an escape of compressed air, until the water.
reached the height of the ingress, unless repairs easily made were effected-By
increasing the air pressure and. opening suitable valves on the floor, the water
would be expelled.,

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Henry Johnson in the Great Seal Patent Office on the
-- 9th June 1883.
".
JOHN HENRY JOHNSON of 47 Lincoln's Inn Fields in the County of Middlesex
Gentleman "IMPROVEMENTS IN SEA-GOING VESSELS a communication to me
from Daniel Ammen a person resident at Beltsville, Prince George's County, and
State of Maryland in tlie United States of America
,
The object of the invention is to produce a vessel of very great strength of
construction of great handiness in movement and capable of being kept afloat, and
even temporarily repaired at sea should a hole of considerable size be made in the
bottom by whatever cause.
And in order that the said Invention may be fully understood I shall now
proceed more particularly to describe the same and for that purpose shall refer
to the several figures on the annexed sheet of Drawings the same letters of reference
indicating corresponding parts in all the figures.
Figure 1.is a transverse section of the middle body of the vessel and Figure 2
drawn to a smaller scale is a side elevation partly in section.
The outline of the vessel as represented in transverse section in Figure 1 is
formed on two semi-conjugates of ellipses the curves of which are prolonged to
meet at the sides as shown at A and A in the plane common to both ellipses the
spaces between the true ellipses and the prolongations of the curves before
mentioned may be filled with sponsoning. C (as shown in the drawing) if the
purpose of the construction would be favored by a sponsoning.
According to the arrangement illustrated the vessel is divided longitudinally
by bulk heads B B¹. Figure 2 exhibits the principle of the construction longi-
tudinally considered. The girders upon which the vessel is built converge
following the curves of a parabola the line of the keel, at the stern following
the line of a parabola from D to E or for any desired proportionate length of
the keel and terminating in the plane of the greatest Beam as shown in the same
figure.
The point towards which these parabolic curves are projected may be at some
distance beyond the terminals or the bow and stern of the vessel and the bow and
stern fashioned and fastened as desired.
The after body as exhibited by Fegure 2 is constructed on the same principle
as is the fore body namely the converging of the girders longitudinally on
parabolic curves, open trusswork as shown in the drawing being employed in the
construction to support the rudder post the object being to support the rudder
post properly and at the same time to avoid the lateral pressure which is opposed
to the action of the rudder when employed in turning the vessel as rapidly as
possible which pressure exists in vessels the after body of which is carried out on
a straight keel. Throughout the vessel transverse bulk heads are placed where
practicable at distances apart, equal to the half sum of the transverse and vertical
diameters of the interior shell of the vessel.
For the prevention of sinking should a considerable hole from any cause be
made in the bottom, it is arranged to close all of the apertures through the deck
and parts other than the fire room or stoke hole by means of air tight scuttles, or
hatches, and to bulkhead off the fire room and any portion of the engine room
desired from the other portions of the interior of the vessel bracing the bulkheads
sufficiently to resist the pressure caused by operating a steam air pump, having the
necessary pipes. attached, through which the various compartments other than the

page_text: fire room or part partitioned off by bulkheads shall be filled with compressed air
and held under a pressure, slightly in excess of that of a column of water having a
height equivalent to the draught of the vessel.
In order to establish communication with the fire room or stoke hole or
other compartment containing compressed air, double doors and an air lock
or intermediate chamber of the size desired are provided and the doors are
furnished with suitable packing or gaskets to make them air tight when closed
and secured.
The chamber is to be provided with an air valve opening into the adjacent
compartment having air pressure by opening which valve the compartment
and the chamber can be brought into equilibrium as to air pressure after securing
the double doors.
Pressure gauges can be fitted in the fire room communicating with all the
compartments and thus any irregularity or defective condition would be brought
to light and could be remedied.
To prevent leakage or reduction of pressure and for increased security all the
scuttles through the various bulk heads should have double faces and corresponding
doors or lids fitted with gaskets or india rubber packing and operated in common
by a lever or otherwise in such a manner as to secure an air-tight joint, whether
the pressure be on the one side of the bulkhead or on the other."
Should a hole be made through one or both bottoms or skins of the vessel, so
long as the internal air pressure is equal or greater than the hydrostatic pressure
no water will rise above the leak however large the hole may be and repairs can
be effected unembarrassed by water by means of mats, planks stanchions wedges
and the like so that were it no longer possible or desirable to maintain an air
pressure the leak would be inconsiderable and controllable by pumping.
Should a hole be made above the bottom but below the water line, there would
be an inflow, proportioned to the hydrostatic pressure impeded more or less by
an escape of compressed air until the water reached the height of the ingress,
unless repairs were immediately effected. By increasing the air pressure and
opening suitable valves in the bottom the water may be expelled after the damage
has been repaired.
Having now described the nature of the said Invention and the manner in
which the same is or may be used or carried into effect I would observe in
conclusion that I am aware that air pressure has been employed for the purpose
of resisting lateral pressure in tunnelling or making deep excavations and that
double doors or air locks have been employed to afford ingress or egress to or from
spaces where artificial air pressure has to be maintained also that in the con-
struction of vessels transverse and longitudinal bulk heads and girders and arched
or "turtle back" decks are not new in themselves alone, but what I consider to be
novel and original and therefore claim as the invention secured to me by the
hereinbefore in part recited Letters Patent is :-
: :
First: In the construction of the bottom portion of sea going vessels as herein-
before set forth the system of double that is to say transverse and longitudinal
arches substantially as hereinbefore described and illustrated in the accompanying
drawings.
Second-In sea going vessels the employment of an open framework for
sustaining the rudder post so arranged as to present a minimum of resistance
to the turning of the vessel substantially as hereinbefore described and illustrated
in the drawing.
Third In sea going vessels the employment of internal air pressure to prevent
vessels from sinking in case a hole is formed in the bottom of the vessel sub-
stantially as herein before described
Fourth-The employment in sea going vessels constructed with chambers or
compartments in which an artificial air pressure is to be maintained of double
doors or air locks and double acting air tight scuttles or hatches for the purpose of

page_text: closing all the apertures through which the air would otherwise be liable to escape
substantially as hereinbefore described.
Fifth-Constructing sea going vessels with transverse and longitudinal girders
curved and combined as hereinbefore set forth with a view to obtaining a structure
of great strength in combination with compartments capable of being filled with
compressed air whereby water is prevented from rising above the level of the leak
all substantially as hereinbefore described and illustrated in the drawings.
In witness whereof I the said John Henry Johnson have to this my
Specification set my hand and seal this fifth day of June One thousand
eight hundred and eighty three.
J. HENRY JOHNSON (L.S.)