Improvements in Masts or Spars for Ships.
Year: 1895

page_text: Date of Application, 19th Feb., 1895--Accepted, 23rd Mar., 1895
COMPLETE SPECIFICATION.
Improvements in Masts or Spars for Ships.
I, WILLIAM EDGAR LEWIS, of 46 Duryee Street, in the City of Newark, and
State of New Jersey, United States of America, Manufacturer of Blinds and Doors,
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:-
The object of this invention is to decrease the weight of the masts, and other
spars, to decrease the size and the resistance thereof, and, at the same time to
increase their strength, and to secure other advantages and results hereinafter
referred to.
The invention consists in the improvements and in the combinations and
arrangements of the parts thereof, as herein set forth and finally pointed out in the
claims.
Referring to the accompanying drawings in which like letters of reference
indicate corresponding parts in each of the figures where they occur, Figure 1
represents a central longitudinal transverse sectional view of a mast or spar
embodying my improvement, Figure 2 is a similar view showing a modification,
Figure 3 is a transverse section taken through line z of Figure 1, Figure 4 is a
transverse section taken through line y of Figure 2, and Figure 5 is a transverse
section similar to that of Figure 1 showing a modification.
In said drawing, A, designates a mast or spar, which is preferably made of wood
and in two longitudinal sections, each side or section being hollowed out at
intervals, as indicated in Figures 1 or 2, or it may be hollow throughout its entire
length if preferred.
The two sections are then firmly glued or cemented together and further secured
at intervals by dowels, a. Through the centre of the mast or spar is arranged a
metal plate, b, composed of steel, iron, bronze, or other appropriate material; said
plate being seated in a rabbet or recess, b¹, in one of the sections and, when the
sections are together, firmly clamping said plate between them, as will be
understood upon reference to Figures 2 and 3.
By arranging the plate, b, across the mast with its edges seated in longitudinal
grooves, it is evident that when the strain comes upon the mast in the line of the
plate, the plate would afford the greatest resistance to bending of the mast; and to
prevent the edges of the plate from splitting the mast when the grooved surfaces
would be forced against the said edges, the narrow plate, c, is arranged at the
bottom of each of the grooves or recesses in the mast at right angles to the plate, /,
as shown in Figure 3, so that any strain against the edge of the plate, b, would be
taken by the plate, c, and the liability of splitting of the mast would be avoided.
By extending this narrow plate, c, the length of the mast it will be readily seen
that the latter is rendered much stronger and, at the same time lighter than a solid
wooden mast of equal dimensions.
When a mast is hollowed out at intervals, as in Figures 1 and 2, the plate, b,
passes between the solid portions which serve to brace said plate and prevent
buckling or bending, as will be readily understood.

page_text: In cases where a mast is made hollow throughout or within a short distance
from its extremities, 1 provide a supplemental plate, e, Figures 3 and 5, which is
inserted and stayed in the wooden shell at one edge in the same manner as plate, b,
and intersects with and is firmly bolted and riveted to said plate, b, as will be
understood.
In the modification shown in Figure 2, in the inside of the wooden shell, at each
side, I arrange a steel plate, c'. Said plates lie in recesses formed in one section
of the mast or spar to receive them, and extend, practically, from one end of the
shell to the other and project inward, say from one inch to two inches toward the
centre, according to the size of the mast or spar, and abut against the plates, d,
arranged transversely with respect to said plates, c, and c¹. Braces e¹, are arranged
diagonally with respect to the shell and in opposite directions throughout the
interior thereof, and firmly secured to said plates, c' and to one another, as plainly
shown in the drawings.
It will be seen from the foregoing that the arrangement of the plates and braces
as described, impart immense strength and rigidity to the mast or spar, and at the
same time materially lessen the weight thereof as compared with a mast or spar
having a solid plate extending entirely across the shell.
In some cases, especially in vessels where a jib is not used, I introduce in the
mast an additional means of strength, to wit:a plate, f, arranged longitudinally
and at right angles to the braces, e', and secured thereto and to one section of the
shell, as indicated in the drawing.
By the construction herein shown and described a mast or spar of a given length
can be much smaller than one made of solid wood, and is much stronger and lighter.
This is of considerable importance in connection with racing yachts, because of their
decreased resistance to the atmosphere, for which purpose the modification shown
in Figure 5 also possesses some advantages, as will be readily understood.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
1. The combination with a hollow wooden mast, the inner surface of which is
grooved longitudinally upon its opposite sides, of a plate, b, extending across the
hollow of the mast with its edges seated in recesses, formed in the latter, and a
cross-plate, c, at the bottom of each recess and arranged at right angles to the
plate, b, whereby the strain upon the edges of the plate, b, will be taken up by the
plate, c, and the liability of splitting the mast along the line of the edges of plate, b,
is avoided, substantially as set forth.
2. In a hollow wooden mast, the combination of a central longitudinal plate, and
transverse braces arranged at intervals between the top and bottom of the mast to
stay and support said plate, as described, and for the purposes set forth.
3. In a hollow wooden mast, the combination of a metal plate passing through
the centre thereof, longitudinally, and seated at its opposite sides in a recess formed
in the wooden shell, a supplemental plate arranged at right angles to the plate
aforesaid and a cross-plate aiso seated in the shell against which one edge of the
supplemental plate abuts, substantially as set forth..
4. The improved mast or spar herein described in which is combined a hollow
or tubular wooden shell composed of two sections joined together longitudinally,
and having an inwardly projecting tongue or plate at each side thereof, and a series
of braces arranged diagonally with respect to the mast or spar and firmly secured
to said tongues or plates and to one another, as described and for the purposes
set forth.
5. The improved mast or spar herein described in which is combined a hollow or
tubular wooden shell composed of two sections joined together longitudinally, and
having an inwardly projecting tongue or plate at each side thereof; a series of
braces arranged diagonally with respect to the mast or spar and firmly secured to

page_text: said tongues or plates and to one another; and a plate passing longitudinally
through said mast or spar at right angles with said braces and connecting therewith
and with one section of the shell, as described and for the purposes set forth.
Dated this 24th dow of Taun 1905
WILLIAM EDGAR LEWIS.
Haseltine, Lake & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.