Improvements in the Construction of Ships' Masts, Yards, sand Booms.
Year: 1891

page_text: Date of Application; 15th July, 1891-Accepted, 15th Aug.,
1891.
COMPLETE SPECIFICATION.
Improvements in the Construction of Ships' Masts, Yards, ſand
Booms.
We, JOHN HENRY BELL, Iron and Rivet Manufacturer of Monkwearmouth
Iron Works, Sunderland and WILLIAM ROCKLIFFE, Engineer of 35 South Street
Durham, both in the County of Durham 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 relates to improvements in the construction of ships? masts yards.
and booms.
According to the present system in vogue the iron or steel plate as the case may
be is first sheared to the requisite shape to allow for the taper of the mast yard or
boom and then it is furnaced and bent in bending rolls to the requisite curve prior
to rivetting up.
This system necessitates an unnecessary amount of labour and as compared with
articles constructed after our invention does not produce so efficient a result.
According to our invention we form plain or corrugated flanged or unflanged
tapered pressed plates by pressing them in a press to the required form and taper.
The plates may be plain flanged tapered plates or plain unflanged tapered plates or
corrugated flanged tapered plates or corrugated unflanged tapered plates. In
every case we press out the plates whether plain or corrugated, whether flanged or
unflanged in a press to the required form and taper. Great economy in the con-
struction of ships' masts, yards or booms can thus be effected compared with the
system of construction now in use.
In certain cases and according as required the mast, yard or boom, constructed as
above in accordance with our invention, may be sheathed with wood.
We will further describe our invention with reference to the accompanying
drawings in which
Figures 1, 2, 3, 4, 5, 6 and 7 show respectively sectional elevations of tapered and
pressed masts, yards or booms as herein above just described!
In Fig. 1, two plain flanged pressed and tapered plates a are shown.rivetted at a'
to form a yard, mast or boom. The sheathing a when such is required may be
bolted to the plating, the heads of the bolts being let into the wood and plugged,
thus giving the appearance of a wooden mast. In Fig. 2, three plain flanged
pressed and tapered plates 6 are shown built up and rivetted in the samo manner.
In Fig. 3, four plain flanged pressed and tapered plates care similarly shown
illustrating the improved construction. In Fig. 4, four single-corrugated flanged
pressed and tapered plates are shown built up to form a mast, yard or boom.
In Fig. 5, four double-corrugated flanged pressed and tapered plates are similarly
shown. In Fig. 6, four triple-corrugated flanged pressed and tapered plates are
shown illustrative of the improved mode of construction. In Fig. 7, two corrugated
unflanged pressed and tapered plates are shown lap jointed and rivetted, Fig. 8
showing a side view of this construction.
The transverse joints of masts, yards or booms constructed of pressed tapered
plates as herein described may be butted and strapped and rivetted or lapped and
rivetted or otherwise jointed in any convenient manner.
The corrugated construction, by increasing the strength of the plating, enables a
lighter section to be used as compared with plain plating and where flanges are
adopted, machine rivetting can be substituted for hand work,
1

page_text: Having now particularly described and ascertained the nature of our said inven-
tion, and in what manner the same is to be performed, we declare that what we
claim is:
1. In the construction of ships-masts, yards or boomsthe use of plain or
-corrugated flanged or unflanged tapered pressed plates, such plates having been 6
pressed or stamped in a machine press to the required form and taper substantially
as and for the purpose herein set forth..
Dated this 10th day of July 1801
A. CRAWHALL CHAPMAN,"
3, St. Nicholas' Buildings, Newcastle-on-Tyne,
Patent Agent for Applicants.