IMPROVEMENTS IN APPARATUS FOR PESPELLING Vrsoma
Year: 1871

page_text: LETTERS PATENT to Edward James Harland, of Belfast, in the
County of Antrim, Ireland, for the Invention of "IMPROVEMENTS IN
APPARATUS FOR PESPELLING Vrsoma.”
Scaled the 26th March 1872, and dated the 17th October 1871.
PROVISIONAL SPECIFICATION left by the said Edward James Harland
at the Office of the Commissioners of Patents, with his Petition,
on the 17th October 1871.
I, EDWARD JAMES HARLAND, of Belfast, in the County of Antrim,
Ireland, do hereby declare the nature of the said Invention for "Ix-
PROVEMENTS IN APPARATUS FOR PROPELLING VESSELS," to be as follows:―
My Invention relates, firstly, to an arrangement of the screw shafting
of vessels propelled by screws where the screw shafts are connected with
the shaft of the propelling engine, by a universal joint, in such manner
as to allow of the propeller being raised or lowered at pleasure, and yet
of its being driven in either its raised or lowered position according as
the vessel is in shallow or deep water.

page_text: According to my Invention I mount the shafting of the propelling
engine so that it shall be in a line or nearly so with the propeller shaft
when the propeller is below the level of the bottom of the vessel, and by
preference when it is in its lowest position, thereby reducing to a mini-
mum the motion which would otherwise be given to the universal joint
connecting the screw shaft with the propelling power when the screw is
lowered, in which position it is used when the vessel is in deep water, and
consequently when it is most likely to be continuously at work. I also
provide what I call a shoo so suspended under the lower periphery of
said propeller that when the propeller is raised to its highest position
the shoe is in line with the bottom of the vessel and closes in the bottom
of screw space against the access of ropes and the like which might
otherwise foul the propeller when the vessel is passing over them, and
also so suspended that when the propeller is lowered this shoe presents
an inclined surface to obstructions that may be met with and thus wards
them from fouling the propeller, or if of such solid nature as a shoal or
rock, the shoe coming first in contact would rise and lift with it the
propeller, the lifting gear being so arranged as to allow of this.
For some purposes it might be preferred to confine the action of this
shoe simply to closing in the bottom of the screw space against the
access of ropes and such like when the propeller is raised, and this I
effect by sliding a shoc, sliding bar, or otherwise from the bottom of
vessel across the bottom of screw space, and to form for the time a con-
nection between the inner and outer stern posts, afterwards to be
withdrawn prior to the screw being lowered. I also so arrange the parts
of the screw lifting gear that when the said shoe should come on a shoal
or rock, or against any obstruction sufficient to force it up and with it
the propeller, that the lifting gear shall as before stated allow the shoe
and screw to rise up, and shall of itself retain the screw and shoe in its
raised position until they shall be duly lifted further out of danger or
lowered again as might be desired; the screw lifting gear may be worked
by hand, or by steam, or hydraulic, or other power.
This Invention is equally applicable to one or more screws in the
same vessel, and may be attached to or combined with one or more stern
posts, or constructed independently of them.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Edward James Harland in the Great Seal Patent
Office on the 17th April 1872.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, EDWARD
JAMES HARLAND, of Belfast, in the County of Antrim, Ireland, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her.
Letters Patent, bearing date the Seventeenth day of October, in the
year of our Lord One thousand eight hundred and seventy-one, in the
thirty-fifth year of Her reign, did, for Horself, Her heirs and suc-
cessors, give and grant unto me, the said Edward James Harland,
Her special license that I, the said Edward James Harland, my
executors, administrators, and assigns, or such others as I, the said:
Edward James Harland, my executors, administrators, and assigns,
should at any time agree with, and no others, from time to time
and at all times thereafter during the term therein expressed, should
and lawfully might make, use, exercise, and vend, within the United
Kingdom of Great Britain and Ireland, the Channel Islands, and Islo
of Man, an Invention for "IMPROVEMENTS IN APPARATUS FOR PROPELLING
VESSELS," upon the condition (amongst others) that I, the said Edward
James Harland, my executors or administrators, by an instrument in
writing under my, or their, or one of their hands and scals, should.
particularly describe and ascertain the nature of the said Invention,
and in what manner the same was to bo performed, and cause the same
to be filed in the Great Seal Patent Office within six calendar months
next and immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Edward James Harland, do hereby,
declare the nature of the said Invention, and in what manner the same
is to be performed, to be particularly described and ascertained in and
by the following statement thereof, that is to say,—
This Invention has for its object Improvements in Apparatus for
Propelling Vessels."
It being well known that "racing" or the irregular speed of marine
screw engines consequent upon the frequent exposure of the propeller,
caused by the lifting and falling of the vessel's stern in a heavy sea, is

page_text: attended by a serious inconvenience, risk to, and loss of power of tho
machinery, and consequent loss of speed to the vessel. The object of
my Invention is to so arrange the propeller or propellers, that they may
be as readily worked at a much greater depth under water, and con-
sequently less frequently exposed, and yet be easily raised to the 5
ordinary level of the vessel's bottom when approaching shallows without
any stoppage of the engines. And further, for light draft steamers or
for any steamers where a large proportion of screw power is desired to
be applied, it having been hitherto found difficult to apply propellers of
sufficiently large diameter to absorb the power necessary for driving 1
them at high speeds when in deeper water, by the arrangements I
propose for lowering the screws such can be accomplished to almost any
extent and yet be readily adjusted again for shallow water without any
stoppage of the engines; and lastly for war vessels the propellers when
so lowered would be the farther from the reach of shot.
And in order that my Invention may be more clearly understood, I
annex Drawings of some simple arrangements to illustrate some of the
modes by which the several parts of my Invention may be applied to
vessels.
Figures 1 represent the stern of a screw vessel in end and side
clevation, and in plan, parts of which are in section.
1
A is the screw propeller; B, the screw shaft; C, the universal
joint; D, the shafting leading to the propelling power; E, the shoo;
F, the outer bearing to screw shaft, to which is attached the lifting rods
and gear G; H is the ordinary screw space somewhat modified in shape:
and open at the bottom, the stern post being hung from the screw frame
and specially stiffened to support the rudder. The lower part of the
inner stern post I, and the after part of the keel are double to allow of
the travel up and down between them of the screw shaft bearing and
the shoe, a strong coupling between each side being retained at the
point J. These views represent the vessel as in deep water with the
propeller down, or nearly half its diameter below the bottom of the
vessel, but with the propeller shaft in line with the rest of the shafting
leading to the engines, in which position the universal joint as a joint is
not working. It will be readily seen that if the shoe were to come in
contact with anything sufficiently solid at say E, it would through the
medium of its hanging links K, and backing L, and working upon its
hinge joint M, force the screw bearing upwards and with it the screw

page_text: and shaft till if necessary the shoe became in line with the keel, in which
position or at any intermediate point the whole would be retained by the
pawls clearly shewn in the Drawing in connection with the lifting rods
and gear G. During this process of elevation the propelling engines
need not be stopped or even slowed, as the universal joint gradually
comes into play, and continues to drive the propeller at this extremo
angle of clevation with but a trifling loss of power or extra strain to
itself.
Under all ordinary circumstances those in command of the vessel
would know what depth of water they had, and would themselves by
the lowering and raising gear G regulate the position of the screw.
The clear space M' in the run, necessary for the elevation of the screw
shaft, and enclosed by the longtitudinal bulkhead on the top and by the
transverse (ship's) bulkhead at the fore end, I prefer left open to the sea
for simplicity, but confine the water to it from the tunnel by a stuffing
box round the screw shaft, working also as a quadrant, or so that the shaft
shall be free both to turn and to rise.
The universal joint is-upon the ordinary well-known gimbal principle,
but fitted with brasses or any other well-known bushings, or otherwise
adjustable in the journals to ensure its true working. If desired it could
be bushed with lignum vitæ and worked in water by dividing a chamber
off from the tunnel and keeping it flooded with stiffing glands, as shewn,
and accessible from the tunnel by water-tight doors..
°
Figures 2 in like manner represent the stern of a screw vessel with the
| screw lowered down, and the screw shaft and shafting leading to the
propelling power in line, but illustrating another form of shoe or bolt to
prevent the propeller from being fouled when up.
N represents a simple form of sliding shoe which is pushed out from
the bottom of the vessel across the screw spaco till.it touches the bottom
of the outer stern post by a rod O or other convenient mode, for pre-
ference and simplicity worked from inside. the tunnel through a stuffing
box on the bulkhead, and thus closing in the bottom of the screw space
against the entrance of warps and such like which might otherwise foul
the screw when passing over them. With this description of sliding shoe
the keel may be solid right to the after end and unite together the
double inner stern post and be of such section as best to suit this
purpose and the working of the sliding shoe.
Figures 2 also shew that

page_text: by carrying up the double section of the inner stern post sufficiently high,
together with the clear space M' in the run, and also by providing
sufficient scope in the universal joint and glands, the propeller P may bo
raised sufficiently high up to allow of its coming above the water for
either the purpose of examination, or repairs, or exchange, or for the
removal of any of the blades, where portable, in place of having to go into
a graving dock. As a matter of precaution the lowering apparatus and
the rod O for forcing out the sliding shoe, to be so connected by any
simple well-known means, so that the operation of lowering the screw
cannot be performed until the sliding shoc has been drawn in.
In Figures 1 and 2 I have shown the screw shaft and bearing
working between a double inner stern post, which I conceive to have
many advantages, but I do not confine myself to this, as on the plea of
economy in first cost in the case of new vessels and as giving the greater
facility for converting existing screw frames to this mode of lowering the
screw, it may be preferred to adhere to a single inner stern post with
guides on the outside for the travel and retention of the outer bearing
and shaft, somewhat similar to the guides as shewn in Figures 3, the
screw shaft entering the shell of the vessel in a similar manner also.
In that case the screw and shaft would be that much off the centre line
of vessel, and the dropping shoc or sliding shoe modified in details to
suit.
Figures 3 in a similar manner represent the after part of a vessel but,
for example, propelled in this case by twin screws so arranged as to be
capable of being lowered and raised to the same effect as in the foregoing
examples, but cither singly or conjointly; and as for the sake of
compactness I prefer the propellers when up to work slightly over-
lapping each other a screw space is in that case required similar to that
for a single screw. I have therefore shewn it as if converted from a
single to a twin screw. In this instance I dispense with any modification
of protecting shoe as scarcely worth the necessary supports to them at
points so far out from the hull.
In this arrangement A, A, are the screw propellers; B, B, the screw
shafts; C, C, the universal joints, D, D, the shafting leading to the
propelling power; F, F, the outer bearings to screw shaft with ball and
socket covers, or so as to allow of the duplex motion of the shaft, and to
which are attached the radial supporting arms G, G, G, G, so arranged

page_text: as to allow the periphery of the one propeller when up or nearly so to
lap over the wake of the other as shewn by the dotted lines in the end
clevation; H is the ordinary screw space which however could bo
dispensed with altogether if compactness were less an object or if the
3 vessel were so wide and shallow as to make it preferable without; I is
the inner stern post, on each side of which guides are fitted for the travel
of the sliding blocks on the upper ends of the supporting arms G, G, and
to which are attached the lifting chains or rods coupled to the lifting
and lowering purchase above. If preferred these guides might extend
to the bottom of the stern post, and then both the top and bottom
supporting arms G, G, could be connected and travel together with the
propeller as one bracket, and thus dispense with the joints at the three
points of attachment. In this case no screw space or opening through
the dead wood would be required.
In this as in the previous examples, when the screws are down the
screw shafts are in direct line with the shafting leading to the propelling
power, for the obvious reasons before named..
I am aware that universal joints have beforė been designed in
connexion with the shafting of screw propellers, and that propellers
and shafts have thus been designed to lower from their normal position
or direct line with the propelling power, and that the propeller and shaft
have been designed to lift out of the water in connexion with a single
joint, and also that the propeller and shaft have been designed to work in
a fixed position below the bottom of the vessel. To such arrangements
therefore I make no claim, but what I claim is, the application of a
universal joint coupling the screw shaft with the shafting leading to the
propelling power, so that as the screw. is lowered to work below the
bottom of the vessel, such separate lengths of shafting shall be brought
into or caused to approach a straight line the one with the other, sub-
stantially as described.
I also claim the application of a lowering shoe to protect the said
propeller when lowered from injury or when raised from being fouled by
ropes when passing over them, substantially as described.

page_text: screw, and when thus lifted may be retained by pawls or equivalent
contrivances, substantially as described.
I also claim the general arrangement of the apparatus substantially as
described and shewn in the annexed Drawings.
In witness whereof, I, the said Edward James Harland have here-
unto set my hand and seal, this Sixteenth day of April, in the
year of our Lord One thousand eight hundred and seventy-two.