IMPROVEMENTS IN ARRANGING, FIXING, AND PROTECTING SCREW PROPELLERS, APPLICABLE TO STEAM AND SAILING VESSELS AIDED AND PROPELLED BY AUX RY STEAM, OR OTHER MOTIVE-POWER
Year: 1881

page_text: LETTERS PATENT to James Mathew Leishman, of the Firm of J. and G. Bulloch
and Co., of 13, Fenchurch Avenue, in the City of London, for an Invention of
"IMPROVEMENTS IN ARRANGING, FIXING, AND PROTECTING SCREW PROPELLERS,
APPLICABLE TO STEAM AND SAILING VESSELS AIDED AND PROPELLED BY
AUX RY STEAM, OR OTHER MOTIVE-POWER." A communication from
abroad E. Cousteau, Shipowner, of Bordeaux, France.
"J
PROVISIONAL SPECIFICATION left by the said James Mathew Leishman
at the Office of the Commissioners of Patents on the 27th October 1881.
JAMES MATHEW LEISHMAN, of the Firm of J. and G. Bulloch and Co., of 13, Fen-
church Avenue, in the City of London. "IMPROVEMENTS IN ARRANGING, FIXING,
AND PROTECTING SCREW PROPELLERS, APPLICABLE TO STEAM AND SAILING VESSELS
AIDED AND PROPELLED BY AUXILIARY STEAM, OR OTHER MOTIVE POWER." (A
communication from abroad by E. Cousteau, Shipowner, of Bordeaux, France.)
According to this Invention the stern of the vessel is constructed with two stern
posts and a protecting case or recess.
The front stern post is constructed with a case or recess of suitable dimensions
to receive the screw propeller into which the same is moved or drawn when the
vessel is sailing.
The front of the back stern post is constructed with a suitable bearing to carry
the end of the screw shaft when put in motion and propelled by steam.
The "Mangin" or double screw propeller is the most advantageous form of screw
propeller for this purpose on account of its reduced projections.
When the vessel is to be propelled by steam the screw shaft is driven or moved
into its bearing in the front of the back stern post by means of well known
mechanism arranged within the hull of the vessel. The screw propeller being
moved out of its protecting case or recess it can then be put in motion.
When the vessel is sailing the screw propeller can be drawn back into the case
or recess in the front stern post, and will not offer any resistance to the speed of
the vessel in sailing.

page_text: As the nature of each of the views is written thereon it will not be necessary to
repeat the same here.
The after part of the ship (which is not reduced) is built with propeller and
stern posts a and b as in ordinary screw steamers. The propeller post a is con-
structed with a frame so as to form a screw case or recess a', the dimensions of
which are calculated to receive the screw propeller c when the ship is under sails.
On the fore part of the stern post ba bearing b¹ is fitted or arranged to receive
and support the end of the screw shaft d when the ship is under steam or other
motive power.
The screw propeller known as the "Mangin" is advantageously used for the
purposes of this Invention in consequence of its reduced projection.
When a ship (arranged as previously described) is propelled by steam power the
screw shaft is driven from inside aft until its end rests in the stern post bearing bl,
the running in and out of the screw shaft being effected by suitable well known
mechanical means, the nature of which it will not be necessary to describe as it
forms no part of these improvements.

page_text: When the ship is under sail and the screw propeller c lodged in its cage a' it
will not injuriously affect the steering of the vessel as it offers no resistance
thereto.
Having thus described the nature of this Invention (communicated to me from
abroad by E. Cousteau) and the manner of performing or carrying the same into
practice, it must be clearly understood that no claim is made to any of the parts
separately which are well known and in common use, but what I claim (on behalf
of the said E. Cousteau) under the above in part recited Letters Patent is,―
The improved method of arranging and protecting a screw propeller so as to
avoid resistance when at rest by enclosing it within a case or recess such as a¹
formed in the stern post a of the vessel, substantially in the manner and for the
purpose hereinbefore described and represented in the Drawings hereto annexed.
In witness whereof, I, the said James Mathew Leishman, have hereunto set
my hand and seal, this Nineteenth day of April, in the year of our Lord
One thousand eight hundred and eighty two.
T 35 T DICITMENT
-
J. M. LEISHY
EXT
(1.S.)