IMPROVEMENTS IN THE CONSTRUCTION OF ICE-BREAKER' SHIPS, AND IN SCREW PROPELLERS FOR THE SAME AND FOR OTHER SHIPS
Year: 1874

page_text: LETTERS PATENT to Edward Griffith Brewer, of 89, Chancery Lanc,
in the County of Middlesex, for the Invention of "IMPROVEMENTS IN
THE CONSTRUCTION OF ICE-BREAKER' SHIPS, AND IN SCREW PROPELLERS FOR
THE SAME AND FOR OTHER SHIPS."-A communication from abroad
by E. J. Weedermann and Sons, of Flensborg, Prussia.
.
PROVISIONAL SPECIFICATION left by the said Edward Griffith Brewer
at the Office of the Commissioners of Patents, with his Petition,
on the 21st February 1874.
I, EDWARD GRIFFITH BREWER, of 89, Chancery Lane, in the County
of Middlesex, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN THE CONSTRUCTION OF 'ICE-BREAKER' SHIPS, AND IN SCREW
PROPELLERS FOR THE SAME AND FOR OTHER SHIPS" (a communication to me
from abroad by E. J. Weedermann and Sons, of Flensborg, Prussia), to
be as follows :—

page_text: power but also a great portion of the weight of the ship is used for
breaking the ice by raising the stem of the ship so high out of water as
to rest on and to cut through the ice.
One mode of accomplishing this result is by forming both ends of the
ship alike and as water tanks, and by emptying and filling the same as
required; one end or the other is raised. Each end is formed with
rudder and propeller.
Another mode is to form both ends alike as before, but each end with
a part projecting some distance beyond the propellers, and forming this
part with a sloping keel or narrow bottom part, the extreme outer end
of which is just above the water level or surface of the ice. On putting
on full steam the ship will gradually ascend on to the ice, and thus aided
by part of the weight of the ship break through the same.
In this case
the tanks may be dispensed with.
The next part of this Invention refers to the construction of screw
propellers, applicable to the aforesaid "ice-breaker ships," and for
propelling purposes generally. The blades of this screw are without any
twist or real screw blade form, but form simply flat surfaces set at an
angle of about 30 to 60 degrees to the axis. The blades are preferably
narrow, strong at the boss, but thin at the outer half-round edge.
construction of propeller exerts a greater pressure than the ordinary
screw, causes less commotion in the water, and is equally effective for
forward or astern propulsion.
This
The aforesaid improvements are applicable not only for ordinary
passenger and goods steamers, but also for steam ferries, troop transport
vessels, diving boats, and other ships or vessels.

page_text: WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-first day of February, in the
year of our Lord One thousand eight hundred and seventy-four, in the
thirty-seventh year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto me, the said Edward Griffith Brewer, Her
special licence that I, the said Edward Griffith Brewer, my executors,
administrators, and assigns, or such others as I, tho said Edward
Griffith Brewer, my executors, administrators, and assigns, should at
any time agreo 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 Isle of Man, an In-
vention for "IMPROVEMENTS IN THE CONSTRUCTION OF ICE-BREAKER' SHIPS, AND
IN SCREW PROPELLERS FOR THE SAME AND FOR OTHER SHIPS" (a communication
to me from abroad by E. J. Weedermann and Sons, of Flensborg,
Prussia), upon the condition (amongst others) that I, the said Edward
Griffith Brewer, my executors or administrators, by an instrument in
writing under my, or their, or one of their hands and seals, should
particularly describe and ascertain the nature of the said Invention, and
in what manner the same was to be 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 Griffith Brewer, 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, reference being had to the accompanying
Drawings, and to the letters of reference marked thereon, that is to
say:
-
The first part of this Invention has for its object so to construct or
build ice-breaker" ships as to enable them to pass through icc of much
greater thickness than heretofore has been attained by any sort of "icc-
breaker" ship or other apparatus.
In order to carry a ship of ordinary or known construction through a
layer of ice it is necessary to steer right against it with the stem, and
thereby break the ice, and to the extent to which this is accomplished
depends upon the power which can be given out by the paddle wheel or
screw. It has been tried to furnish the stem of the ship with various

page_text: ice-breaking apparatus, but their efficiency also depends upon the pro-
pelling power of the vessel. This Invention however differs materially
from the ordinary methods.
According to this Invention the propelling power of the ship is also
utilized it is truc, but this power is considerably increased by reason of
the peculiar construction of the vessel, whereby a great portion of the
weight of the vessel itself is utilized for breaking the ice. Simultaneously
with the horizontal breaking, or cutting, or crushing of the icc, the
latter receives a pressure from above downward thereby that the keel of
the fore end of the vessel passes over it, according to the well-known
principle of the inclined plane, and thus a great part of the weight of the
vessel exerts a downward pressure on the icc. It is obvious that the ice
must be very thick to withstand such a pressure simultaneously with the
cutting pressure of the stem or keel.
Figs. 1 and 2 of the accompanying Drawings illustrate two methods
whereby this Invention may conveniently be carried into effect. Both
vessels are built alike at both ends with rudder and propeller, thus
obviating the necessity of turning about and cuabling them to
manoeuvro in narrow waters. The keel may be straight or sloping
upwards at cach end, as shown.
Fig. 1 is shewn with one end raised over the ice surface A, B, the
other end being below the same proportionately. When this vessel then
is propelled forward the keel at the stem will cut and break through the
ice as above described; the vessel will run up so far on to the icc that
the latter will not be able to withstand the pressure, and then it will
break. In the same way the vessel can act as an ice-breaker in the
opposite direction; the other end is then raised up over the ice while its
opposite end is lowered. This peculiar raising and lowering of one end
or the other is accomplished in a very simple way, viz., by the aid of
water tanks, cisterns, or holds with fixed bulkheads arranged at cach
cnd. These water receivers are filled or emptied as required through
self-acting valves, and by the steam power of the vessel. At Fig. 1 part
of the vessel's skin is left out to shew this water cistern C. According
as these cisterns aṛo filled or emptied one end or the other of the ship is
raised or lowered.
Fig. 2 shows a construction of ship where this raising or lowering
method is not necessarily applied, because of the peculiar build of tho

page_text: ship. In this case the ship is built so that the stem is bound in all
cases to come above the ice, and thus will exert an enormous pressure
on it and break it. For this purpose cach end is formed with a part
projecting some distance beyond the propeller, and this part has a
sloping keel or narrow part, the extreme outer end of which is
just above the water level or surface of the ice. On putting on full
steam the ship will gradually ascend on to the ice, and thus aided by
part of the weight of the ship break through the same. In this case the
water holds or tanks may be dispensed with.
ship. In this case the ship is built so that the stem is bound in all
cases to come above the ice, and thus will exert an enormous pressure
on it and break it. For this purpose cach end is formed with a part
projecting some distance beyond the propeller, and this part has a
sloping keel or narrow part, the extreme outer end of which is
just above the water level or surface of the icc. On putting on full
steam the ship will gradually ascend on to the ice, and thus aided by
part of the weight of the ship break through the same. In this case the
water holds or tanks may be dispensed with.
Vessels may obviously be built according to the principles here
delineated without closely resembling either Fig. 1 or Fig. 2, but rather
forming intermediaries between the two.
When these improvements are applied to sailing ships the steam
power of the hoisting engine or crab may be used for filling and
emptying the water receivers; and in certain cases, such as with ferries,
where a fixed point of attachment for a rope in front of the vessel can
be obtained, the steam power can be applied to the hauling along of the
vessel, and thus breaking the ice.
رو
The next part of this Invention refers to the construction of "screw
propellers applicable to the aforesaid "ice-breaker" ships, and for propell.
ing purposes generally. This form of screw is here shewn applied to cach
end of the "ice-breaker ships illustrated by Figs. 1 and 2, and to a larger
scale by Figs. 3, 4, and 5, Fig. 3 being a perspective view of same;
Fig. 4 a side elevation, and Fig. 5 an end elevation. The blades of this
screw are without twist or real screw blade shape, but form simply flat
surfaces set at an angle of about 30 to 60 degrees to the axis. The
blades are preferably narrow, strong at the boss, but thin at the outer
rounded edge, which latter by preference is made half-round or there-
abouts, in order more easily to get clear of any pieces of timber or other
bodies with which the screw might come in contact. The blades are by
preference placed at an angle of 45 degrees with the axis. A propeller
constructed according to this Invention exerts a greater pressure than
the ordinary screw propeller; it causes less commotion in the water, and
is equally effective for ahead and astern propulsion.
The aforesaid improvements in "ice-breaker" ship are applicable not
only for ordinary passenger and goods steamers and exploring vessels

page_text: but also for steam and other ferries, troop transport vessels, diving boats,
life-boats, and other vessels.
And having thus fully described and ascertained the nature of this
Invention, and in what manner the same is or may be performed, I
declare that I claim as the herein described improvements in the con-
struction of "ice-breaker ships, and in screw propellers for the same and
for other ships,-
Firstly. The construction and formation and methods of action of
ships used as "ice-breaker ships, by utilizing a portion of their weight
for ice-breaking purposes, substantially as shewn and as described.
Secondly. The construction and formation and methods of action of
ships fitted with water holds, tanks, or cisterns, and used as "ice-breaker"
ships, substantially as shewn and as described.
Thirdly, The form and construction of propeller, substantially as shewn
and as described with reference to Figs. 3, 4, and 5.
In witness whereof, I, the said Edward Griffith Brewer, havo here-
unto set my hand and seal, this Twenty-first day of August, in
the year of our Lord One thousand eight hundred and seventy-
four.