Improvements in Armoured Vessels.
Year: 1897

page_text: Date of Application, 18th May, 1897-Accepted, 25th Sept., 1897
COMPLETE SPECIFICATION.
Improvements in Armoured Vessels.
I, ELIAS MATTISON JOHNSON, of Spuyten Duyvil, New York, in the County and
State of New York, United States of America, Manufacturer, do hereby declare
the nature of this invention and in what manner the same is to be performed, to
be particularly described and ascertained in and by the following statement:-
My invention relates to armour plated vessels which are protected by plates
having hardened surfaces. The armoured vessels as now constructed are surrounded
either entirely or partially by a single layer or thickness of Harveyized or other
hardened plates, which vary in thickness from four to eighteen inches according
to the location it is desired to protect.
The object of the hardened or Harveyized plate is to prevent a shot or projectile
from piercing the surface of the plate, or in other words it is to break, crush or
partly destroy the point of the projectile. When the point is thus destroyed the
shot loses its penetrating qualities and is smashed or broken on the plate, only
penetrating the same a short distance.
To accomplish these results, the face of the Harveyized plate is made extremely
hard, this hard surface becoming softer and tougher as the back of the plate is
reached. It is found that if a shot once penetrates this hard surface and keeps
its point, if it has velocity enough, it will pierce or go through the plate. By
recent improvements the point of the projectile is so protected that the surface of
the Harveyized plate is now nearly as easily penetrated as before the plate was
put through the hardening process.
The object of the present invention is to construct the armament of a vessel
of two layers or thicknesses of plates with a space between them, so that a pro-
jectile which may penetrate the outer layer after passing through this first layer
or thickness will be prevented from penetrating the second layer of Kardened
plates, its point being smashed on these second plates or layer.
The invention consists in an armour plated vessel provided with two layers or
thicknesses of plates with a space there between, and the inner layer or plates
surface hardened, as hereinafter fully described.
In the accompanying drawing, the figure is a transverse sectional view of a
portion of an armoured vessel constructed in accordance with my invention.
In the said drawing the reference numeral 1 designates the hull of the vessel,
2 the inner layer or thickness of surface hardened plates, 3 the outer layer or
thickness, 4 the space therebetween, and 5 studs for keeping the plates of the two
layers or thicknesses apart.
The projectiles which these layers or thicknesses are intended as a protection
against, are of that class or character which are provided with a hard solid
conoidal point, having a soft metal cap which will receive the impact when the
projectile strikes the plate, thus protecting the point and preventing it from being
smashed or broken. By constructing the vessel with two layers of such plates
with a space between, the projectile may pass through the first plate without
injury but upon reaching the second plate or layer the protecting cap having been
destroyed, the point will be smashed on the said second plate, and the projectile

page_text: prevented from penetrating the same. As the object of the first plates or layer is
to break down the cap on the head of the projectile it is not necessary that these
plates or layer should be surface hardened, as the cap will be destroyed even when
a soft iron plate is used. The space between the layers will prevent the back
bulge of the first plate caused by the impact of the projectile from injuriously
affecting e plates of the second layer. The plating may extend entirely around
the hull, as indicated in the drawing, or it may extend only partially around,
without departing from the principle or scope of this invention.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what I
claim is:-
1. An armoured vessel provided with two layers or thicknesses of plates with
a space therebetween, the plates of the inner layer or thickness being Harveyized
or surface hardened, substantially as described.
2. A vessel provided with a protecting plating or layer of thick plates Harveyized
or surface hardened on their outer sides and an outer plating or layer of thin plates
with a space between the two layers, substantially as described.
Dated this 18th day of May 1807
BOULT & WADE,
Agents for the Applicant.