AN IMPROVED METHOD OF PRO- PELLING AND STEERING STEAM VESSELS AND APPARATUS THEREFOR AND CONNECTED THEREWITHL
Year: 1879

page_text: LETTERS PATENT to George Robert Dunell, of Inglewood, Erith, in the County
of Kent, Grontloman, for the Invention of "AN IMPROVED METHOD OF PRO-
PELLING AND STEERING STEAM VESSELS AND APPARATUS THEREFOR AND
CONNECTED THEREWITHL." A communication from abroad by John Brown
Herreshoff and Jamos Brown Ierroshoff, both of the Town and County of
Bristol, State of Rhode Island, United States of America.
Sealed the 21st March 1879, and dated the 8th January 1879.
PROVISIONAL SPECIFICATION left by the said George Robort Dunell at the
Office of the Commissioners of Patents on the 8th January 1879.
GEORGE ROBERT DUNELL, of Inglewood, Erith, in the County of Kent, Gentleman.
"AN IMPROVED METHOD OF PROPELLING AND STEERING STEAM VESSELS AND
APPARATUS THEREPOR AND CONNECTED THEREWITH." A communication from
abroad by John Brown Herreshoff and James Brown Herreshoff, both of the Town
and County of Bristo!, State of Rhodo Island, United States of America.
It is a woll known fact among sailors and others that much difficulty is at times
experienced in steering, turning, stopping, or reversing the motion of a steamer or
other vessel or boat, especially the stooring when the engines are reversed and the
boat is going rapidly astern.
Such
This
The object of our Invention is to remove some or all of those difficulties which wo
do in the following manner :-Instead of placing the engine which drives the boat
amidships, we prefer to place ours further forward, while the shaft we prefer to
incline at such an angle as to pass through the bottom or keel of the boat.
shaft being carried down into the water to a depth sufficient to enable the propeller
when attached thereto to revolve beneath the keel or bottom of said boat.
shaft we encase in a tube; the whole may be then supported by bars or braco irons,
but we prefer to use for this purpose a metallic chainber, preferably of a V shaped
section and varying in its depth from the shallow and surrounding the shaft where
it passes through the bottom or keel of the boat to the deepor end where it surrounds
the shaft close to the screw or propeller. At the top of this chamber is a flange
on either side so as to permit of its being bolted or otherwise securely attached to
the bottom or keel of the boat. Said chamber wo use as a condenser into which
the exhaust steam from the engine is convoyed while the induction pipe leading to
the air pamp is attached to lowest convenient point of said chamber. At times this

page_text: chamber may be partially filled with lead or other heavy substances to act as ballast
and give greater stability to the boat.
It is a fact that much propelling power is lost if the axis of the screw or propeller
be not parallel with the lino of motion of the boat. In order therefore to secure the
best results when the shaft is pitched at an angle as horoin-before described wo
spring or curvo it sufficiently to bring the axis of the propeller into or near the
dosired position. While for the purpose of steering the boat and to permit of its
course being rapidly and easily changed or reversed wo placo a rudder at each end
thereof supported in any convenient manner so as to hang clear of the bottom keel
or sides, which arrangements we make in order to permit of their turning or making
a complete revolution upon their axes or rudder heads. We may use but ono
rudder, hung as described, such rudder being placed either in the extreme bows or
at the storn of the boat, but when we desire to turn the boat in an exceedingly
small space we prefer to use two rudders, as set forth.
"
Some of the advantages of carrying the shaft through the bottom or keel and
placing the screw or propeller approximately beneath the centre of the boat may be
enumerated as follows:-The propeller always being in solid water the engine nover
"races," and there is consequently no loss in the effective driving power. Again,
the V shaped chamber or condenser surrounding the shaft acts also as a "skeg
contre board or false keel, and being centrally located forms a species of pivot,
enabling the boat to be more readily and rapidly turned, as the rudder or rudders
are situated at a distanco from said pivot and give thereby great steering or
directing leverage or power.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said George Robert Danell in the Great Seal Patent Office on the 3rd
July 1879.
GEORGE ROBERT DUNELL, of Inglewood, Erith, in the County of Kent, Gentleman
"AN IMPROVED METHOD OF PROPELLING AND STEERING STEAM VESSELS AND
APPARATUS THEREFOR
from
AND CONNECTED THEREWITH." A communication
abroad by John Brown Herreshoff and James Brown Herreshoff, both of the Town
and County of Bristol, State of Rhode Island, United States of America.
It is a well known fact among sailors and others that much difficulty is at times
experienced in steering, turning, stopping, or reversing the motion of a steamer or
other vessel or boat, especially the steering when the engines are reversed and tho
boat is going rapidly asteru. The object of our Invention is to remove some or all
of these difficulties, which we do in the following manner, reference being had to
the accompanying Drawing, which forms part of this Specification, and in which
Fig. I. shows a sectional elevation of a torpedo boat, while Fig. II. is a sectional
elevation on the line x, x.
"
Instead of placing the engine which drives the boat amid-ships we prefer to place
ours further forward, as shown, while the shaft " A we prefer to inclino at such an
angle as to pass through the bottom or keel of the boat; such shaft, which may be
straight or curved (as hereafter more fully set forth), being carried down into the
water to a depth sufficient to onable the propeller when attached thereto to revolve
beneath the keel or bottom of said boat. This shaft we encaso in a tube, the whole
may then be supported by bars or brace irons, but we prefer to use for this purpose
a metallic chamber approximately of a V shaped suction and varying in its depth
from the shallow end surrounding the shaft where it passes through the koel or
bottom of the boat to the deeper end where it surrounds the shaft close to the screw
or propeller. At the top of this chamber is a flange on either side so as to permit of
its being bolted or otherwise securely attached to the bottom or keel of the boat.
When employing condensing engines we use said chamber as a condenser into which
the exhaust steam from the ongines is conveyed by means of pipe B, while the
induction pipe leading to the air pamp is attached to the lowest convenient point of
said chamber. At times this chamber may be partially filled with lead or other
boavy substances to act as ballast and give greater stability to the boat.
When not using condensing engines the shaft is oncased in a tube, as before
described, while the place of the condenser is taken by a skeg or false keel formod
of metal or wood which gives the same support to the shaft.
It is a fact that much propelling power is lost if the axis of the screw or propellor
bo not parallel with the line of motion of the boat. In order therefore to secure the
best results when the shaft is pitched at an angle, as herein before described, we
spring or curve it sufficient to bring the axis of the propeller into or near the desired
position.
The proper spring for a shaft of 3 inches diameter and twenty two feet long I
have found to be about equal to the carvo obtained by placing a twenty pound
weight at the centre of said shaft when only supported at its ends, while for the
purpose of steering the boat and to permit of its course being rapidly and easily
changed or reversed we place a rudder at each end thereof, supported in any con-
venient manner so as to hang clear of the bottom keel or sides. This arrangement
wo make in order to permit of their turning or making a complete revolution upon
their axis or rudder heads. We may use but one rudder C, as shown and hung
as described, such rudder being placed either in the extreme bows or at the stern
of the boat; but when we desire to turn the boat in an exceedingly small space we
prefer to use two rudders, as set forth. Some of the advantages of carrying the
shaft through the bottom or keel and placing the screw or propeller approximately
at the centre of the boat may be enumerated as follows:-The propeller alway

page_text: being in unlistarbed solid water the ongine never races and there is consequently
no loss in the effective driving power. Again, the V shaped chainber or condensor
surrounding the shaft acts as a "skeg" centro board or false koel, and being cen-
trally located forms a species of pivot enabling the boat to be more readily and
rapidly turned as the rudder or radders are situated at a distance from said pivot,
and give thereby great steering or directing leverage or power.
Having thus described the nature of my Invention as communicated to me by my
foreign correspondents, what I claim and desire to secure by Lotters Patent is,—
1st. The rudder or rudders so hung or placed that they may turn or perform a
complete revolution upon their axis.
2nd. The screw in the position described, in combination with the condenser, as
described.
3rd. The scrow in the position described, in combination with the rudder or
rudders, as described.
4th. The sprung or curved shaft, as and for the purposes specified.
5th. The sprung or a straight shaft in combination with the rudder or rudders,
as described.
6th. The spring or a straight shaft, in combination with the condensers, ns
doscribed.
7th. The condenser in the position described, as and for the purposes specified.
In witness whereof, 1, the said George Robert Dunell, havo hereunto Bet my
hand and seal, this Third day of July, in the year of our Lord 1879,
GEO. R. DUNELL. (L.B.)