IMPROVEMENTS IN PROPULSION OF SHIPS OR VESSELS
Year: 1884

page_text: PROVISIONAL SPECIFICATION.
I ALEXANDER MAC LAINE of No 1 Queens Elms Belfast, in the County of
Antrim, Shipowner, do hereby declare the naturo of my said invention for
IMPROVEMENTS IN PROPULSION OF SHIPS OR VESSELS, to be as follows:―
.
I construct ships or vessels propelled by steam or other motive power with two
separate propeller spaces placed one before the other at the after end of the vessel,
and I place a screw propeller ou each side of the vessel on the Twin Screw system,
one opposite each propeller space with its blades projecting through the space,
revolving across the centre line of the vessel and transversely overlapping the
blades of the other propeller.
By preference, I place one of these screw propellers a considerable distance
forward of the other and construct a shaft bearing or support for each screw,
placed to suit its own propeller space; and I may place two screws with two
separate propeller spaces as aforesaid at the forward as well as at the after end of
the vessel.

page_text: I ALEXANDER MAC LAINE of. No 1 Queens Elms, Belfast, in the County of
Antrim, Shipowner do hereby declare the nature of my invention for IMPROVE-
MENTS IN PROPULSION OF SHIPS OR VESSELS and in what manner the same is to
be performed, to be particularly described and ascertained in and by the following
statement:
I construct ships or vessels propelled by steam or other motive power with two
separate propeller spaces placed one before the other at the after end of the vessel-
one opposite each propeller space with its blades projecting through the space
revolving across the centre line of the vessel and transversely overlapping tho
blades of the other propeller; and in order that my said Invention may be more
fully understood I shall now proceed to refer to the drawings upon the sheet hereto
nnnexed the-same-letters of reference-indicating-the-same-or-corresponding parts
throughout all the figures.
Fig I Is an elevation sheer plan of the after end of a vessel showing two
_separate propeller spaces placed one before the other with a screw propeller on
.each side of the vessel one opposite each propeller space.
Fig II Is a full breadth plan of the bottom of the after end of the saine vessel
showing the two propellers each with its blades projecting through its own separate
propeller space arranged to revolve across the centre line of the vessel and trans-
versely overlap or cross over the position of the blades of the other propeller.
Fig III Is a stern view of the same vessel looking from aft showing the two
propellers with their blades overlapping each other across the centre line of the
vessel.
a a are two separate propeller spaces placed one before the other bb are two
propellers each opposite its own propeller space with its blades projecting across
the centre liue of the vessel c c and transversely overlapping the blades of the other
propeller at d d.
Having now described the nature of my said Invention and in what manner the
same is to be performed I declare that what I claim is
The construction in ships or vessels propelled by steam or other motive power
of two separate propeller spaces placed one before the other at the after end of the
vessel combined with overlapping propellers substantially as described and shown
in the drawings hereunto annexed.
Dated his L
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