Year: 1887

page_text: Date of Application, 8th Jan., 1887
Complete Left, 10th Oct., 1887
Complete Accepted, 11th Nov., 1887
I, JOSIAH VAVASSEUR of the London Ordnance Works, Bear Lane, Southwark in
the County of Surrey, Engineer do hereby declare the nature of this invention to be
as follows:
This Invention has for its object improvements in steel projectiles for piercing
armour plates.
In the manufacture of such projectiles difficulty is experienced in tempering them
uniformly throughout and breakage and change of form is liable to occur in the
tempering operation. This arises from the metal being of very different thicknesses in
different parts. To avoid these difficulties I make the projectile in parts as follows.
There is a shell open at the base and of tolerably uniform thickness, and this receives
within it a filling block preferably made in two pieces, and behind the filling block a
plug is screwed into the base of the shell. The rear part of the filling block is simply
a tempered cylinder of steel. The fore part of the block is so shaped as to fit the
cavity in the head of the outer shell; it has a series of steps formed on its exterior and
these bear on a corresponding series of steps formed within the shell. There is a
passage from end to end of this part of the block to facilitate tempering, and this
passage at the rear end may be enlarged to form part of a cavity to receive a bursting
charge. The plug is also of tempered steel and when screwed into the base of, the
shell it abuts upon the rear part of the filling block and this in turn abuts against the
fore part of the filling block and holds it in place.
Sometimes I make the cavity in the fore part of the shell without steps and insert
into it a filling of lead or other material. The rear part of the filling block in this
case resembles a flat headed shell, it is formed with steps upon it near its fore end,
and there are corresponding steps within the body of the shell. A screw plug in the
base of the projectile abuts as before on the filling block and forces it home to its
place. The cavity for the bursting charge is entirely formed within the filling
block.
In some cases I make the point of the projectile in one piece with a stem of the full
length of the projectile; there is an axial passage in this stem to facilitate tempering.
The stem receives upon it an approximately cylindrical block of the full diameter of

page_text: the projectile and this is secured by screwing to the stem at its rear end; in front it
abuts upon a shoulder around the stem in rear of the point of the projectile.
These projectiles may be made of the usual form, cylindrical in the body and with
an ogeval head of uniform circular curvature. Or in order to facilitate penetration
without weakening the point of the projectile, the curvature of the head may be
altered.
In the longitudinal section the radius of curvature at the point may as heretofore
be from one and a half to two diameters and in passing back from the point may be
progressively increased until it amounts to say four diameters; the curve also meeting
the cylindrical body of the projectile a good deal further back than it does in the usual
form.
D .
1

page_text: 1, JOSIAH VAVASSEUR of the London Ordnance Works, Bear Lane, Southwark, in
the County of Surrey, Engineer, 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:-
This invention has for its object improvements in steel projectiles for piercing
armour plates.
In the manufacture of such projectiles difficulty is experienced in tempering them
uniformly throughout and breakage and change of form is liable to occur in the
tempering operation. This arises from the metal being of very different thicknesses
in different parts. To avoid these difficulties I make the projectile in parts as
follows: There is a shell open at the base and of tolerably uniform thickness, and
this receives within it a filling block preferably made in two pieces, and behind the
filling block a plug is screwed into the base of the shell. The rear part of the filling
block is simply a tempered cylinder of steel. The fore part of the block is so shaped
as to fit the cavity in the head of the outer shell; it has a series of steps formed on its
exterior and these bear on a corresponding series of steps formed within the shell.
There is a passage from end to end of this part of the block to facilitate tempering,
and this passage at the rear end may be enlarged to form part of a cavity to receive a
bursting charge. The plug is also of tempered steel and when screwed into the base
of the shell it abuts upon the rear part of the filling block and this in turn abuts
against the fore part of the filling block and holds it in place.
Sometimes I make the cavity in the fore part of the shell without steps and insert
into it a filling of lead or other material. The rear part of the filling block in this
case resembles a flat headed shell, it is formed with steps upon it near its fore end,
and there are corresponding steps within the body of the shell. A screw plug in the
base of the projectile abuts as before on the filling block and forces it home to its
place. The cavity for the bursting charge is entirely formed within the filling
block.
In some cases I make the point of the projectile in one piece with a stem of the
full length of the projectile; there is an axial passage in this stem to facilitate
tempering. The stem receives upon it an approximately cylindrical block of the full
diameter of the projectile and this is secured by screwing to the stem at its rear end ;
in front it abuts upon a shoulder around the stem in rear of the point of the
projectile.
These projectiles may be made of the usual form, cylindrical in the body and with
an ogival head of uniform circular curvature. Or in order to facilitate penetration
without weakening the point of the projectile, the curvature of the head may be
altered.

page_text: In the longitudinal section the radius of curvature at the point may as heretofore
be from one and a half to two diameters and in passing back from the point may be
progressively increased until it amounts to say four diameters; the curve also meeting
the cylindrical body of the projectile a good deal further back than it does in the
usual form.
In order that my said invention may be fully understood and readily carried into
effect I will proceed to describe the drawings hereunto annexed.
Figure 1 is a longitudinal section of a steel projectile built up in parts.
Figure 2 is a similar view of a built up projectile of another form.
Figure 3 in like manner shows a third form.
In each cash the projectile is designed so as efficiently to carry out the object of
the invention, that is to say, in each part of the projectile the variations in thickness
are not large or such as materially to interfere with the uniform tempering of the
piece.
Figure 4 shows in elevation the head of a projectile designed in accordance with my
invention.
Figure 5 is a diagram illustrating the method I adopt for tracing the generating
curve of the head.
In Figure 1-a is the external shell of the projectile. b and c are the two parts of a
filling block inserted within it; they are made to fit accurately within the shell a and
are forced into their places. is a plug also of tempered steel screwed fast into the
shell behind the parts b and c.
e is a block of
In Figure 2 a is the external shell and d the base plug as before.
compressed lead or other harder metal which replaces fore end of the part in
Figure 1. is a tempered steel filling block behind the base plug d, it is closed at
the fore end.
In Figure 3a is the external shell, in this case it is open at the fore end and g is a
separate point with a stem g¹ extending to the base of the projectile and there screwing
into its place.
The projectiles shown by the Figures 1, 2 and 3 are of the usual external form, the
curve of the ogival head having a radius of two diameters.
Figure 4 by the full line shows an improved form of head and by the dotted line a
two diameter ogival head. It will be seen that the improved form, at the point, is as
obtuse or somewhat more obtuse than the other and the curvature is somewhat
greater but the curvature decreases rapidly and continuously until it meets the
cylindrical body which it does much further back than in the ordinary form namely
at the point whereas the corresponding point on the dotted line is at i.
By thus making the head of the projectile with a progressive curvature the strength
of the point is maintained whilst penetration is facilitated; the head also if upset will
be less injuriously distorted and the liability to crack is lessened.
Figure 5 shows the way in which I trace the curve for the head of the projectile.
I first draw two parallel lines a and b at a distance apart equal to the semi diameter
of the projectile. I then subdivide this distance into equal parts by drawing between
a and other parallel lines c c² 3 and c; the more numerous these lines the more
accurately will the curve be traced. I next draw a line d parallel to and at a
distance from it equal to the radius of curvature selected for the nose of the projectile.
(In Figure 4 this is 165 diameters). I then draw a line e parallel to band at a
distance from it equal to the radius of curvature at the shoulder of the projectile
where the curve of the head meets the cylindrical body. (In Figure 4 this is four
diameters). Between d and e 1 draw other parallel lines ff and dividing the
distance between d and. e into equal parts. Then from a centre at any point in the
line d and with the radius which has been selected for the nose of the projectile I
describe an arc g h connecting the lines a and c¹. I now draw another arc hi from

page_text: the point where the first are meets the line c¹ and joining the line c¹ and c²; the radius
of this arc is the distance between the lines band and the centre of the are hi is
upon the line f¹. Similarly I draw other arcs ij, j k and kl from centres on the
lines and e respectively.
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. A projectile substantially as described consisting of a hollow shell of tempered
steel with an inner or filling piece or pieces also of tempered steel fitted within the
hollow shell.
2. A tempered steel projectile built up in parts substantially as described in respect
to Figure 1.
3. A tempered steel projectile built up in parts substantially as described in respect
to Figure 2.
4. A tempered steel projectile built up in parts substantially as described in respect
to Figure 3.
5. A projectile having a head of progressive curvature and substantially as described
in respect to Figures 4 and 5.
Dated this och rasy
LOOT
CARPMAEL & Co.,
Agents for the Applicant.
CARPMAEL & Co.,
Agents for the Applicant.