Improvements in Apparatus for Arresting the Motion of Navigable Vessels.
Year: 1898

page_text: PROVISIONAL SPECIFICATION.
Improvements in Apparatus for Arresting the Motion of Navigable
Vessels.
I, HENRY SIMPSON, of 10, Crooked Lane, Liverpool, in the County of Lancaster,
Lamp Manufacturer, do hereby declare the nature of this invention to be as
follows:-
My present invention has reference to certain improvements in my previous
invention of apparatus for arresting the motion of navigable vessels, for which I
have obtained Letters Patent dated 24th November, 1892, and numbered 21427,
the object being more particularly to improve the details of construction of the
arresters described in the specification to my patent aforesaid, with a view to increase
the strength thereof.
The said arresters are box-like structures built up of plates united by angles; they
are approximately triangular in plan and rectangular in elevation, and each is
mounted on a vertical spindle which is secured to the top and bottom plates of the
box at the centre of its greatest length. When in use, each arrester is subjected to
a heavy water pressure distributed over its front side which is approximately a
vertical plane, and as it is centrally supported by its spindle, it constitutes a double-
ended cantilever.
I find that the back of the arrester, which is under compression, and the top
and bottom plates to which the spindle is attached, are liable to become
deformed under the heavy stresses brought to bear upon them, and I accord-
ingly modify the construction so as to afford additional strength to these
parts.
I make the back of cellular structure by adding within the box a plate parallel
to the back and some little distance from it. This may be rivetted to the top
and bottom plates by independent angles, or, by bending its edges twice at right
angles it may be rivetted between the back plate and the angles which connect
the latter to the top and bottom plates. Transverse plates or bulkheads are
fitted at intervals to tie the plates of the front and back together, so as to give
them greater stiffness.
As the arrester is supported entirely by its spindle, I find it necessary to
provide means for distributing the supporting force and conveying it directly to
the back and front, so as to relieve the top and bottom plates. I prefer, with
this end in view, to rivet to the top and bottom plates, and preferably on the
inside thereof, strong forgings or steel castings which are bossed round the
spindle and well spread out towards the back and front plates, to the angles of
which they are rivetted. I may also fit a transverse bulkhead bossed round the.
spindle and rivetted to the back and front plates.

page_text: In a simpler construction, the back may be tied to the spindle by a vertical
plate bent like a letter U round the spindle and rivetted at its ends to the back
plate.
Dated this 6th day of August 1898.
SLOAN & LLOYD BARNES,
34, Castle Street, Liverpool, Agents for the Applicant.
Improvements in Apparatus for Arresting the Motion of Navigable
Vessels.
I, HENRY SIMPSON, of 10, Crooked Lane, Liverpool, in the County of Lancaster,
Lamp 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 present invention has reference to certain improvements in my previous inven-
tion of apparatus for arresting the motion of navigable vessels, for which I have
obtained Letters Patent dated 24th November, 1892 and numbered 21427, the
object being more particularly to improve the details of construction of the arresters
described in the specification to my patent aforesaid, with a view to increase the
strength thereof.
I have illustrated my present improvements in the accompanying drawings, in
which Fig. I is a sectional plan of one of the arresters and Fig. II is a sectional
elevation on the line A-A of Fig. I; the general arrangement of the arresters and
the gear for operating them are not described nor illustrated in the present specifica-
tion, as these are fully set forth in my said prior specification.
As will be seen by reference to Fig. I, each arrester 1 is a box-like structure built
up of plates united by angles; it is approximately triangular in plan and is mounted
on a vertical spindle 2 which is secured to the top and bottom plates 3 and 4 at the
centre of its length.
When in use, that is to say, swung so that the front side 5 is perpendicular to the
axis of the vessel 6, as indicated in dotted lines in Fig. I, the arrester is subjected to
a heavy water pressure distributed over the side 5, and as it is centrally supported by
its spindle 2, it constitutes a double-ended cantilever.
I have found that the back of the arrester, which is under compression, and the
top and bottom plates 3 and 4, are liable to become deformed under the heavy
stresses brought to bear upon them, and I accordingly make the back of box-like or
cellular form, 7 being the inner and 8 being the outer plating. Additional stiffness
is also given to the structure by two or more transverse plates or bulkheads 9.
As the arrester is supported entirely by its spindle 2, I have found it necessary to
provide means for distributing the supporting force and conveying it directly to the
back and front, so as to relieve the top and bottom plates. With this object in view,
I reinforce these plates in the vicinity of the spindle by the strong forgings or steel
castings 10, which are bossed round the spindle and well secured by rivetting at
numerous points through the back and front angles of the arrester. The parts 10
are lightened by the hole 11, and are of course cut away to clear the casing 12 which
is necessary to clear the spindle 21 of the other arrester.
The parts are united by angles and rivets after the manner common in structures
of this class. As shown in Fig. II the parts 10 are so arranged that their rivetting
passes through the angles and the plating; the outer angles 13 are preferably
arranged as shown in this figure, so as to facilitate the rivetting up of the bounding
plates 5 and 8 after the structure has been otherwise completed.

page_text: In the case of arresters of very large size, additional bulkheads such as 9 may be
fitted, and one of these may be bossed or folded round the spindle 2 so as more
effectually to transmit the load thereto.
Instead of making the spindle circular where it fits in the arrester, and keying or
feathering it thereto, it may be made of polygonal cross-section, thus dispensing with
keys and enabling the spindle to be readily withdrawn if required.
It is to be understood that I make no claim herein to any of the subject matter
described or claimed in my prior specification aforesaid, but,
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:-
The improvements in ship arresters, substantially as described and illustrated.
this 5th day of May 1899.
SLOAN & LLOYD BARNES,
Chartered Patent Agents, 34, Castle Street, Liverpool.