IMPROVEMENTS IN ANCHORS
Year: 1846

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
RODGER, of Shaw field Street, Kings Road, Chelsea, Lieutenant in the Royal
Navy, send gi ceting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Letters Patent under the Great Seal of the United Kingdom of Great Britain
and lieland, beaning date at Westminster, the Eighteenth day of May, in
the ninth year of Hei reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said William Rodger, my exors, adññors, and assigns,
Ile especial licence, full power, sole privilege and authority, that I, the said
William Rodger, my eñois, adirois, and assigns, or such others as I, the said
Williain Rodger, my exois, adiiors, or assigns, should at any time agree
with, and no others, fiom time to time and at all times during the term
of years therein expressed, should and lawfully might make, use, exercise,
and vend, within England, Wales, and the Town of Berwick-upon-Tweed,
my Invention of "IMPROVEMENTS IN ANCHORS;" in which said Letters Patent
is contained a proviso that I, the said William Rodger, shall cause a particular
description of the nature of my said Invention, and in what manner the same
is to be performed, by an instrument in writing under my hand and seal,
to be inrolled in Her said Majesty's High Court of Chancery within six
calendar months next and unmediately after the date of the said in part
recited Letters Patent, as in and by the same. reference being thereunto had,
will more fully and at large appear

page_text: NOW KNOW YE, that in compliance with the said proviso, I, the said
William Rodger, do hereby declare that the nature of my Invention,
and the manner in which the same is to be performed, are particularly
-described and ascertained in and by the Diawing hereunto annexed, and the
following description thereof (that is to say):-
My said Invention of Improvements in Anchors relates principally to those
parts which are usually termed the "arms," the "palms," and the "stock;"
and the object I have in view is to obtain the greatest amount of holding
power and strength with a given weight of iron.
proper relative position.
DESCRIPTION OF THE DRAWING
Figure 1 is an elevation or side view of one of my improved anchois, of
about ten hundredweight (on a scale of one inch to the foot), exhibiting a
section of the stock, and an edge view of the stock plate in their respective
places. Figure 2 is a plan of the same, together with the stock and and
shackle, &c. complete. Figure 3 is a front view of the stock; and Figures
4 and 5 are sections thereof taken at the parts indicated by the dotted lines.
Figure 6 is a plan of the stock plate, with the stock key laid across it in its
Figure 7 is an edge view of the-stock-plate,-also
exhibiting the stock key in connection with it. Figure 8 is a side view of the
square of the anchor, and an edge view of the stock plate, but without the
stock Figure 9 is a plan of the same, representing also the stock plate and
the key which confines it in its proper place. Figure 10 is a back or end
view of the crown, arms, and palms, the dotted lines shewing that the arms
are "shut" at the crown in the usual manneı.
sections of the shank taken at the dotted lines.
section of the shank, shewing the mode of laying the bars or slabs composing
it flatways in the direction of the greatest strain. This is in imitation of a
coach spring, and with a view to render the shank less liable to be broken by
sudden jerks or strains in the act of "weighing," and the same method is
adopted in regard to the aims. Figures 14 and 15 are sections of the aims
taken at the dotted lines.
Figures 11 and 12 are
Figure 13 is likewise a
.
By these Figures it will be seen that the arms of my improved anchor are
formed on the principle of a wedge, the inside or front being made thinner
than the outside or back part. The object of this arrangement is to avoid
disturbing the ground in front of the arms, and to augment the lateral
For the same reason,
pressure of the ground against the sides of the arms
and in order to retain as long as possible the rubbing action of the ground
against the sides of the arms, the chamfer on the outside or back part is made

page_text: smaller than that on the inside or front part, and I have ascertained by actual
experiment that the ground, by reason of its elasticity, immediately closes in
and reunites behind the anchor thus constructed, and thereby tends to exclude
the water, which, when permitted to enter, has a tendency to force the anchor
forward, as is the case with the large palmed anchors of the usual construction,
which when dragged leave a wide rut o trench behind them.
Figure 16 is another sectional form, which, although in some respects
inferior to the forms just described, is nevertheless much superior to those in
common use. The arms of anchors of the ordinary construction being usually
made of an oval form, or of an oval flattened a little at the sides, and some-
times nearly 1ound, now it is obvious that when any body of a round or oval
section passes through the ground the fiction and lateral pressure of the
ground ceases for the most part to produce any retarding effect beyond the
centre of that body, and moreover these sectional forms are far from being
the most efficient in regard to strength. To remedy these defects, then, is the
object of this my said Invention; and I may here remark, that in fixing upon
the sectional forms herein described and recommended I have had no less
regard to an increase of strength in the direction of the greatest strain than
to an augmentation of friction and lateral pressure against the sides of the
aims, which I have found to produce an immense increase in the holding
power of my improved anchors. But although my principal attention has
been directed to the improvement of the "arms," the "palms," and the
"stock," I have not neglected the no less important part usually termed the
"shank;" for it will be seen by a reference to Figure 1, and the section close
to the "throat," Figure 12, that it possesses greater strength in the direction
of the greatest strain to which anchors are usually subjected than any other
anchor of equal holding power and weight now in use, and likewise as
much strength as is required in a lateral direction. And as the shanks of
anchors are fiequently broken at a short distance from the "stock," I may
now refer to the section, Figure 11, by which it will be seen that that part
of my improved anchor is of a square form, which is better calculated to resist
torsion than the rectangular form of the other parts of the shank, and
I have ascertained that it is in consequence of the twisting action
proluced by the cable getting under the stock that anchors are broken at
the part referred to. In fact, I believe that no other action (excepting
a collision) could produce the effect, for the sectional area at the part
alluded to is much greater in proportion to the leverage acting upon it
than the sectional area of the other end of the shank. I do not, however,
mention this peculiarity of form as being new, having in reality used it for
$

page_text: several years with another anchor of my Invention, and with the most
beneficial result, for I have never known it to fail. I now return to the aims.
Figure 17 is a section of the palm taken at the dotted line in Figure 1.
-By-this-Figure it will be seen that the form of my improved palm is widely
different from all the forms of palms now in use, for, instead -of-presenting_a
flat surface at right angles to the resisting medium, the fiont of the palm 15
"bevilled." and thus presents two surfaces obliquely to the line of traction,
with one intermediate surface (comparatively small) at right angles thereto :
and as any two sides of a triangle are longer than the third, and as the semi-
circumference of a circle is longer than its diameter, three surfaces present a
greater area of resistance than could be obtained by a flat palm of the same
length and breadth, and, moreover, their centre of resistance is considerably
deeper in the ground, which is a decided advantage. I have now, however,
to advert to a principle which has been as yet but only slightly glanced at.
If, for example, a wedge having parallel sides be placed flatways at the depth
of two or three feet beneath the surface of the ground, its resistance to any
impelling force in the direction of its point, whether by traction or by
propulsion, would be in proportion to the superincumbent weight which
would have to be raised up as the wedge-advanced, but if the wedge_be
placed edgewise at the same depth as before, it will be found that its resistance
would be greatly increased by the indefinite extent of the ground laterally,
and therefore the wedge could not be moved forward without compressing the
ground on either side of it to such an extent as to allow its thick end to pass.
This then is precisely the, action of the edges of my improved palm when
the aim of the anchor is buried to a certain depth in the ground, as repre-
sented by Figures 22 and 23. The action of the oblique surfaces being in
the duection of the perpendiculars thereto, is partly lateral and partly vertical,
and will be clearly understood by a reference to Figures 10, 21, 22, 23, and 25,
but the palm is always buried to such a depth that its vertical action upon the
ground does not produce any perceptible elevation of it at the surface.
Figure 18 is a section of another palm, presenting a convex surface to the
resisting medium, but which I do not consider so efficient as that already
described Figure 19 is a front view, and Figure 20 is a back view of the
palm and aim before it is curved oi bent Figure 21 represents a front view
of the arm and palm when the anchor is buried up to the middle of the
shank, and Figure 10, already referred to, exhibits a back view of the arm
and palm in the same position. Figure 22 is a front view, and Figure 23 is
a back view of the aim and palm when the anchor is buried up to the middle
of the upper aim, the dotted line A, A, Figure 1, representing the surface of

page_text: the ground Figure 24 is a top view of the palm in the same position, and
Figne 25 is a section of the palm, taken at the dotted line in Figure 24,
which will more clearly illustrate its action than as represented by Figure 17.
In this position it will be seen that the back part of the palm (which is slightly
concave) is resting upon the ground, and as the water is completely excluded
from beneath it, and the rut also filled up behind, as before stated, it is
obvious that the holding power of the anchor will be augmented to a
considerable extent, for it will not only have the pressure of the atmosphere
upon the palm and the whole of the lower arm, but it will likewise have the
weight of the superincumbent fluid pressing upon them. And if the anchoi bo
diagged whilst in this position the resistance will be still further increased by
the fiction upon the back of the palm, which will be almost equal to that on
the front of it. The hole in the crown of the anchor is for the purpose
of attaching the buoy chain to it, instead of fastening it round the armis in
the usual manner, which latter mode adds a useless weight of chain, and tends
to prevent the anchor from sinking into stiff ground. With regard to the
"stock," it will be observed by the sections Figures 4 and 5 that the front is
thicker than the back pait, which gives it a tendency to buy itself in the
ground, and the projecting part in the middle, Figure 3, with the addition of
the stock plate, represented in Figures 1, 2, 6, 7, 8, and 9. forms a 1ut for
the shank to fall into, and when the anchor is diagged a mound of earth will
be thrown up in fiont, which will eventually completely cover both the stock
and shank of the anchor, and doubtless increase its holding power, for every
practical seaman has experienced the effect of getting the anchor "sand
warped" The holes in the ends of the stock are for the purpose of lightening
these parts where weight would be prejudicial, and of facilitating its sinking
into the ground after the anchor has been "canted " I may here state that a
wooden stock is applicable to this as well as to any other anchor, and when
used I would recommend its being made of one piece, and fitted with plates,
&c, in the manner represented by the Diawing annexed to the Specification
of my former Platent for Certain Improvements in Anchors," molled the
Twenty-fourth of January, One thousand eight hundred and thirty-four, but
I consider the iron stock represented by the annexed Diawing, and herein
described, decidedly preferable, excepting perhaps for very large anchois.
Figure 26 is a side view of one of my improved kedge anchors of about two
hundredweight (on a scale of one inch to the foot), exhibiting the stock in
section. Figure 27 is a plan of the same with the stock complete. Figure 28
is a back or end view of the "clown." "arins," and "palms." Figure 29 is
a front view of the aim and palm,-which it will be perceived is formed in such

page_text: a manner as to prevent its hooking the boat's gunwale in the act of throwing
it, an accident of no unfrequent occurrence, and sometimes attended with loss
of life by the upsetting of the boat. Figures 30 and 31 are sections of the
stock, which is "rove" through the shank in the usual manner. The other
parts of my improved-hedge-being-similar to those of my improved anchor
previously described, it is not necessary to lengthen the description of it-by-a
more particular explanation of the properties of its various parts; but as
my improvements in the palms of anchors admit of several modifications, I
shall now describe in what manner they may be applied to anchors (in other
respects of the usual construction), in order to meet the convenience of such
manufacturers as have not the requisite machinery for making anchors on my
improved plan, in the manner already described. In the first place, then, I
shall endeavour to explain in what manner the anchors already made may be
materially improved in their holding properties at a very small expense.
Figure 32 is a side view of the arm of an anchor of about ten hundredweight,
of the usual construction, and Figure 33 is a back view of the palm and arm
before it is curved or bent. Figure 34 is a back view of the palm and arm
when the anchor is buried up to the middle of the upper arm; the dotted lines in
this Figure representing, for the sake of contrast, the position which my improved
palm would assume under the same circumstances, as shewn by-Figure--23.
Figure 35 is a section of the palm and blade of the arm taken at the dotted
line in Figure 32. Now in order to avoid disturbing the ground in front (which
is one of the defects of a large palm), and with a view to place the resisting
surface as low as possible, I propose bending the palms backwards, as represented
by Figure 36, and also shewn in Figure 32 by the dotted lines representing an
edge view of the palm thus altored. But as many of the palms are very
imperfectly welded on to the blade of the arm, and perhaps would not admit
of being bent as much as represented by Figure 36, I would recommend in
such cases that the palms should only be bent to the extent exhibited by the
clotted curved lines in Figure 35, bearing in mind that even a slight deviation
from the flat surface will be an improvement. Tho practice at present is to
make the front of the palms slightly concave, or, as it is technically termed,
"dished," and this doubtless under the impression that when thus made it
takes a firmer hold; but the fact is it carries the ground along with it, and if it
be of an adhesive quality the anchor becomes "shod," and rises out altogether,
which renders it absolutely necessary to let go another anchor when it would
have been desirable to have ridden by one only. I may now state that in
making anchors in other respects of the usual construction, but with the palms
bent backwards, it will be better to make them shorter than they are bioad,

page_text: whereby the lateral pressure against the sides of the arm will be considerably
augmented Figure 37 is a side view of the aim of an anchor, with a palm
of this description welded on in the usual manner, but bent backwards, as
represented by the section, Figure 38, the inside of the blade being previously
1ounded in order to adapt it to the curve of the palm. Figure 39 is a front
view of the palm and arm before they are bent; and the dotted line A, A, in
Figure 37 shews the extent of the rubbing surface, which would be completely
lost by using a palm of the ordinary form and size represented by Figures 32
and 33 Figure 40 is a side view of the arm of an anchor with the palm
welded on to the back of the blade instead of being welded on to the front
part in the usual manner. Figure 41 is a front view of the same, and
Figure 42 is a section of the blade and palm taken at the dotted line in
Figure 40. This palm would be still more efficient if made slightly concave'
in the back part, as represented by the dotted lines in Figure 42 The advan-
tages of this method are, that it places the palm in the lowest possible position
(when it acts precisely in the manner of a wedge placed edgewise, as already
described,) and it retains the lateral pressure upon the blade down to the very
point on extremity of the arm Great care, however, must be taken to ensure
sound workmanship, and for the large sizes of anchors it would certainly be
better to make the palms "out of the solid;" but the small sizes suitable for
kedges might be easily accomplished, and for that purpose, as well as for
the stream anchors, I would recommend a palm of the form represented by
Figure 29, to prevent its hooking the boat's gunwale in the act of throwing
it. Figure 43 is a front view of the aim and palm worked "out of the solul,"
with the blade in front, a section of which, taken at the dotted line A, A, is
represented by Figure 42. This palm possesses all the advantages of that
represented by Figures 40 and 41, and can only be objected to on account of
the additional expence in making it.
Having thus described the nature of my Invention of "Improvements in
Anchors," and the manner in which the same is to be carried into effect, I
wish it to be distinctly understood that I do not mean or intend to claim as
my present Invention anything herein described which has heretofore been
used; but I do mean and intend to claim as my Invention the peculiar shape
of the arms, the sectional form of which is based on the principle of a wedge,
the inside being made thinner than the outside or back part, as herein-before
described.
I also claim the peculiar shape of the palms, which, instead of presenting
a flat surface at night angles to the resisting medium, the fiont part of my
improved palms is bevilled off on each side so as to present two oblique

page_text: surfaces to the ground, and thereby producing a greater power of resistance
than has hitherto been obtained by anchors of equal weight and strength
I also claim the method of improving the holding qualities of the anchors
on the old construction (whether already made or now in actual use) by
bending the palms backwards so-as-to-render_the_punciple of my Invention
available to them.
I also claim the method of making anchors in other respects similar to those
of the old construction, with palins welded on as usual, but bent backwards,
as here:n-before described.
I also claim the method of welding on the palms on the back of the blade
instead of their being welded on in front in the usual manner.
I also claim the method of forming palms "out of the solid," but with the
blade in front instead of being on the back of the palm, as is usual.
I also claim the method of making the iron stock, having the front part of
it thicker than the back part, and likewise the application of the stock plate
in the manner berein-before described; but I wish it to be distinctly under-
stood that I do not claim the method of fitting the stock upon the square of
the anchor in the manner represented by the Drawing hereunto annexed.
In witness whereof, I, the said William Rodger, have hereunto set my
haud and seal, this Fourteenth day of November, in the year of our
1.oid One thousand eight hundied and forty-six.
AND BE IT REMEMBERED, that on the Fourteenth day of November,
in the year of our Lord 1846, the aforesaid William Rodger came before our
said Lady the Queen in He Chancery, and acknowledged the Specification
aforesaid, and all and every thung therein contained and specified, in form
above written. And also the Specification aforesaid was stamped according to
the tenor of the Statute made for that purpose.
Eniolled the Fourteenth day of November, in the year of our Lord One
thousand eight hundred and forty-six.