A NEW OR IMPROVED ARRANGEMENT OF SHIFTING SCREW PROPELLER
Year: 1872

page_text: LETTERS PATENT to Leopold Christian Warneck, of Place St. Pierre,
3, Nantes, and of 37, Boulevard Bonne Nouvelle, Paris, in the
Republic of France, Merchant Captain, for the Invention of "A
NEW OR IMPROVED ARRANGEMENT OF SHIFTING SCREW PROPELLER."
COMPLETE SPECIFICATION filed by the said Leopold Christian Warneck
at the Office of the Commissioners of Patents, with his Petition
and Declaration, on the 20th July 1872, pursuant to the 9th Section
of the Patent Law Amendment Act, 1852.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, LEOPOLD'
CHRISTIAN WARNECK, of Place St. Pierre, 3, Nantes, and of 37, Boulevard
Bonne Nouvelle, Paris, in the Republic of France, Merchant. Captain,
send greeting.
WHEREAS I am in possession of an Invention for: "A NEW OR
IMPROVED ARRANGEMENT OF SHIFTING SCREW PROPELLER," and have petitioned
Her Majesty to grant unto me, my executors, administrators, and assigns,
Her Royal Letters Patent for the same.

page_text: NOW KNOW YE, that I, the said Leopold Christian Warneck, do
hereby declare that the following Complete Specification, under my
hand and seal, fully describes the nature of my said Invention, and the
manner in which the same is to be performed :-
As a captain making long voyages I have often had occasion to
verify the serious losses to ship owners resulting from the calms or light
breezes which arrest or lessen the progress of a vessel to such an extent
as always to cause considerable loss of time, sometimes even to doubling
the length of the voyage; also the risks incurred by being unable, from
want of a motive power, to seize and profit by favourable moments. My
shifting propeller will be found a great aid in getting under weigh, to
keep off a coast when becalmed, and with the swell setting in to the
shore, in straits, in the long calms at the change of the monsoons in
the Indian and China seas, to pass the Strait of Magellan, and thus
avoid the delays occasioned by the frequency of gales off Cape Horn, it
will also finds its useful application for the passage of the Red Sea, in
the Mediterranean, on the coast of Africa, as well as the passage of the
equator, latitudes in which calms are so long and so frequent; finally,
for avoiding collisions where there are a number of vessels having no
stecrage way, and which might otherwise collide.'
+
My improved shifting propeller by reason of its simple arrangement
is hoisted like a poop boat and even more easily, by means of a tackle
on each side of the poop, and of a double girt, line coming from the guy
to the frame of the screw, which is consequently shifted very promptly
and easily without apparatus, manoeuvering, or. difficulty.
My novel arrangement of shifting screw propeller has for object to
obviate all the inconveniences above set forth, and to considerably shorten
the voyage of ships; 15 tons of coal will suffice for 25 days' travelling,
day and night; therefore, supposing a voyage of 100 days, its use during
one-fourth of the voyage, and the little loss of cargo space incurred, the
economy, of my system will be at once, evident.
My screw worked by a small steam engine is, capable of giving to a
ship a regular minimum speed of 3,700, metres, per hour, that is to say,
two nautical miles, which will enable it always to travel in calm
weather. This speed can always be added to one or two knot breezes.
These circumstances of calms or light winds are so frequent that they
enter to the extent of half or at least a third in the greater number of
voyages (this is casily ascertainable by consulting shipping gazettes),
.

page_text: and if it be considered that a ship costs 8 or 12 pounds a day, the
value will at once be seen of a propeller so practicable, so easy of
application, and above all, of so insignificant a cost..
My system is so simple that not the least alteration of the ship
is necessary, nor any disarrangement or loss of time. For example, it
is not necessary to lengthen its keel, to give it a second sternpost, nor to
change the position of the rudder, it is not even necessary to dock the
vessel in order to fit my apparatus, as it can be put in position whether
the ship be in a roadstead or at a quay; the horizontal shaft not passing
through the stern post gives one chance the less of a leak; finally, if
the screw fouls it is easily freed and lifted by means of its tackle.
If an accident should happen to the apparatus or to the engine when
a ship is anchored far from a port, as on the coast of Coromandel, it is
not necessary to run into a harbour the one or the other can be put
into a boat and be sent on shore for repair. without any disturbance to
the ship, nor the slightest delay.
J
When the breeze is blowing strongly and the screw becomes useless,
it is hoisted by the side tackle and it comes like a poop boat to the level
of the poop, upon which rests the upper part of the frame of the screw.
In this position the arrangement presents to the sea, when the vessel
is running, before the wind or in heavy weather, less surface than a poop
boat. In ports where it may be inconvenient, the entire arrangement
may be taken to pieces, be lashed secure from any shock as well as the
slide E (see Fig. 1 of Drawing.)
The resistance of a ship being given by the following formula R =
K S V³, of which K is the coefficient of resistance, variable according to
form and dimensions; S, submerged surface of the midship frame; V³,
the cube of the speed per, second. By making this calculation it will
be seen that a three horse-power, or thereabout is sufficient to give a
speed of two nautical miles per hour to a ship of from five to six hundred
tons, but five or six horse-power might be used without difficulty. The
screw shown on the accompanying Sheet of Drawing is combined to
produce this result with three horse-power in a dead calm.
Five or six horse-power double piston horizontal steam engines are
obtainable, measuring about 32 inches in breadth and height, by five
feet in length, and which can easily be placed in the cabin instead of a
caisson. Such machines weigh between six and eight hundredweiglit.

page_text: In studying my novel arrangement of shifting screw from the double
point of view of a general application, and of a more special application
to each kind of sailing vessel, I have deemed it desirable to transmit
power from the auxilliary motor to the screw by placing at the upper
part of the frame an intermediate shaft carrying a driving pulley, and
two cranks keyed at right angles, which, by the aid of two connecting
rods and two cranks set on the screw shaft, communicate motion to the
screw in a very efficacious manner. Although I apprehend no danger
from a direct transmission by means of a chain a simple band half
india-rubber and canvass necessitating no particular arrangement will
now suffice to transmit motion to the screw, because the action is only
to be exercised in calm weather or light winds, further, the pulley of
the intermediate shaft and the band are sufficiently raised above the
water. In order to submerge the screw very readily I have jointed the
horizontal frame of the screw upon the rods and supports, so that when
the entire arrangement is lifted it can in no way be a source of em-
barassment in handling the guy or the spanker.
My Invention may also be adopted to ascend and descend rivers, and
in entering and leaving docks, the expense and annoyances of a tug
being thus avoided.
On the accompanying Sheet of Drawing forming part of this Specifi-
cation, Figure 1 is a longitudinal elevation of the stern part of a vessel
fitted with my shifting screw and its engine, Figure 2 a front view
of the stern of same, and Figure 3 a plan view. All these Figures are
drawn to a scale of 12th.
The shifting screw A is keyed on its axle a moveable in two bearings
on the frame B, one of which is arranged for the thrust bearing; at the
two ends of the shaft a are keyed at right angles two cranks a¹, a', to
which are attached the two connecting rods c, c, arranged so as to com-
municate to the screw the motion of the shaft C moveable in two other
bearings in the frame B, having also at its ends two cranks c³, c¹, and in
the middle the pulley D. It is desirable that the pulleys should have
a somewhat projecting flange to keep the band from coming off. The.
frame B is bolted at its upper part upon a support E fixed at the stern
of the ship, and tied at its lower horizontal part by the two rods F, F,
jointed at ff, to the ship. Two other cross rods G, G, secure suitable
rigidity to the entire arrangements. Upon the four points o, 0, 0, 0, of

page_text: .
the horizontal frame B, Fig. 3, are fixed four supports which find their
point of attachment upon the vertical frame B where they like balance
beams unite in giving to the entire arrangement a very great rigidity,
which may however be obtained by other known means, or by increasing
the proportions of each part of the framework attached to the frame,
as well as the frame itself. Thus the main rods may be strengthened
especially at the part P, P¹, by two wooden cheeks, between this part
P, R, would be comprised. If outside the ship there are ring bolts,
catheads, or any projections of from 18 to 20 inches for example, this
inconvenience will be obviated by placing an iron bar or brace of two
or three inches of projection at most from f to R. This projection
cannot be otherwise than advantageous, as the greater it is the more it
will lessen the curve of the rods F, F. The driving engine H is placed
at the stern of the ship, and by means of suitably arranged toothed
gearing I, I, actuates an intermediate shaft J, at the end of which is
keyed the driving pulley K. This shaft is arranged parallelly to the
upper shaft of the frame B of the screw to which it transmits motion.
This shaft is movable so as to permit the easy regulation of the tension
of the band L. This machine may easily be removed and be placed near
the hatchways to be used as an auxiliary motive power for all the
requirements of the ship either to work the capstern; or for loading or
unloading, or for working the pumps in case of serious leakage; one
seaman will in any case suffice as stoker and to work the engine.
The boiler with all its accessaries may be placed in the cook's galley,
where it would be entirely out of the way, and be put in communication
with the machine by steam pipes passing along and beneath the range
of belaying pins, where they would be secure from blows, while exposed
to view in case of escape of steam and easily got at for repairs. In case
of fire a single jet would be sufficient to master it, and a small elastic
tube passing from the boiler to a refrigerator would give a supply of
fresh water for the crew, emigrants, and animals.
It will be evident that by the arrangement shown on the Drawing it
is very easy to lower and lift the shifting screw when in a dead calm or
a light breeze it is desired to employ the auxiliary motive power, all
that is necessary is to fix the two rods F, F, to their fixed joints f, f;
carrying the entire arrangement, then by the aid of the two tackles P, P;
coming from the poop on to the main rods, which have first held them
in the position shown in red at. Fig. 1, they must be lowered, the upper

page_text: part of the frame B be bolted on the support E and the main rods be
bolted at R. The engine being also fixed in position as well as the
driving band, it may be at once set at work.
When it is desired to momentarily suspend the action of the propeller
it is only necessary to fix the tackle, unbolt and lift the arrangement to.
the position shown in red at Fig. 1. This operation may be assisted by
a double girt line coming from the guy or spanker on to the frame of
the screw.
'In order that the frame of the screw may not in this latter position
interfere with the handling of the guy or spanker the two draw rods F, F, 1
may be jointed at their lower part on the frame B; then likewise unbolt
the two transversal rods G, G, and joint them at P, P, on the main
draw rods F, F, so that the frame B may come down at first behind the
ship so as to offer less projection, as shown in. red at Fig. 1.
To sum up. My novel arrangement of shifting screw constitutes with 1
its motive-power engine an auxiliary apparatus of little weight, slight
bulk, and reduced cost, easily worked as well as easily set up and taken
to pieces with the means at hand, and sufficiently efficacious to propel
a ship in calms and light winds, so as to considerably shorten voyages
and otherwise render important advantages to ship owners.
2
Many ship owners have incurred the expense of a steam launch for
tugging their ships in calms, but the numerous inconveniences which it
was easy to foresee caused them to abandon it, in fact a launch of such
weight could not be set afloat and raised inboard several times a day, and
still less at night, to meet the caprices of the wind; it is impossible, as 2
the whole time would be spent in these manoeuvers, and they would'
prevent the ship from profiting by the wind.
I have entered into all these details in order to answer objections
which might be raised against the value or the advantages of my system
of shifting screw, to which it is always easy to give any needful amount 3
of rigidity by known means. The cases in which my apparatus may give
important advantages are too numerous for recital here, the experience of
mariners of all nations will supply instances in recalling to their minds
the difficult circumstances in which they might have profited thereby, and
ship owners, captains, and insurers will find it greatly to their interest 3
to adopt a system which will diminish the length of voyages and the
risks of navigation. Consignees themselves will always give the pre-
ference to ships provided with a propeller, because as the voyage must in

page_text: most cases be shorter the cargo will be less exposed to damage arising
from the moisture which heat and want of air always develope in the
hold of a ship becalmed in the torrid zone, principally when the cargo is
composed of rice, grain, or other merchandize which heat will cause to
ferment. The same advantages are found in the carriage of emigrants
or of animals. Insurers will also find their insurances lighter, risks of
every kind being greatly lessened, and captains will by its aid have less
anxiety and a more fortunate navigation.
In witness whereof, I, the said Leopold Christian Warneck, have
hereunto set my hand and seal, this Fifteenth day of July, in
the year of our Lord One thousand eight hundred and seventy-
two.