IMPROVEMENTS IN SCREW STEAMSHIPS OR VESSELS, AND IN THEIR PROPELLING AND STEERING MECHANISM
Year: 1877

page_text: LETTERS PATENT to John William Sadler, of Glasgow, in the County of
Lanark, North Britain, Master Mariner, for the Invention of "IMPROVEMENTS
IN SCREW STEAMSHIPS OR VESSELS, AND IN THEIR PROPELLING AND STEERING
MECHANISM."
PROVISIONAL SPECIFICATION left by the said John William Sadler at the
Office of the Commissioners of Patents on the 20th June 1877.
JOHN WILLIAM SADLER, of Glasgow, in the County of Lanark, North Britain,
Master Mariner. "IMPROVEMENTS IN SCREW STEAMSHIPS OR VESSELS, AND IN
THEIR PROPELLING AND STEERING MECHANISM."
This Invention has reference to certain improvements in connection with the
screw propellers and their shafts and fittings for screw steam-ships or vessels, for the
better propulsion of these ships, and in consequent improvements connected with
the rudder and steering gear, all which will enable large ships to be built so as to
draw much less depth of water and to be either propelled at a higher speed or with
less power than heretofore, with equal or even greater stability.
And the nature and novelty of the Invention consist in forming the large deep
narrow part of the keel, below the stern, where the screw shaft usually passes out
through a cylindrical channel a little larger than itself, of two frames or thicknesses,
with a deep narrow longitudinal radial or rectangular channel between them
forming two stern posts (instead of one as formerly), with the deep narrow
transverse recess between them, parallel and just wide enough to allow the bush
block of the stern neck journal of the screw shaft to be raised to the usual level, or
even higher, out of the water, and lowered in a new or improved manner quite
down to near the keel, so that the screw which would be keyed on the extreme end
of the shaft would, when the vessel is in deep water, work with its blades quite
down below the line of the keel in solid water not disturbed by the pitching motion
or displacement of the ship.

page_text: The back end of this stern length of the screw shaft would be coupled by a
universal joint to the end of the shaft passing out from the engines inside througth
the usual stern stuffing box pipe; and when the universal joint coupling is desired
to be kept dry, a stuffing box could be formed on a deep slide, fitted on the radially
rising and falling screw shaft outside the coupling, working in a water-tight channel
or partition, leaving a dry well or chamber for the coupling, and a cover might be
fitted over this at the quarter or under deck for the engineers getting in to inspect
and connect or disconnect this universal coupling.
The said carrying or raising and lowering stern journal bearing block of the screw
shaft might, as usual, be bushed with lignum vitæ or other hard wood, or it might
be made with collar and grooved journal, and bearing with white or gun metal
bushes as a thrust block to take the end thrust off the universal joint coupling, and
this bearing block, in either case, may be carried and raised, or lowered by one or
two strong screw bars working in nuts, either attached to the block or turned in or
with a revolving wheel or wheels above by hand or tooth gearing; or rods may be
used, fitted with screw or scroll racks, worked by ordinary geared wheels, screws, or
scroll wheels, by hand or motive power.
Conjoined with this arrangement of these improvements connected with the
propeller two rudders would be used, mounted to work close up to the outside shell
or wall of the recessed or double stern post, with their back edge rather within this,
to work quite clear in front of and on each side of the keel and propeller, the
rudders being worked by any suitable gearing above at the top of their rudder
posts, so that one rudder turns out from the port side and the other from the
starboard side, to. port or starboard the ship respectively, and vice versa, the one
turns in towards the line of the keel as the other turns outwards thorefrom.
... It is to be understood however that other forms of rudders or steering blades may
be used, such as oscillating or sliding vanes, working out through narrow angled
chambers under the port and starboard quarters, the one being projected-out into
action as the other is drawn in out of action by suitable lever or rack and wheel
gear.
When twin screw ships are fitted on this new or improved system the ordinary
arrangement of central rudder would do, and two double-cased vertical radial
channels or chambers would be fitted one under each quarter for the shafts of the
port and starboard screw shafts to be raised and lowered, with the screw propellers
quite forward in advance of the centre stern post, so that the rudders could be put
hard a-port or a-starboard without interfering with the action of either screw;
either or both of the screw propellers could be raised in shallow. water and lowered
in deep water to give the improved action and propelling effect described in reference
to the single screw arrangement first referred to.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed.by.
the said John William Sadler in the Great Seal Patent Office on the 20th
December 1877.
EE
JOHN WILLIAM SADLER, of Glasgow, in the County of Lanark, North Britain, '
Master Mariner. IMPROVEMENTS IN SCREW STEAMSHIPS OR VESSELS, AND IN
THEIR PROPELLING AND STEERING MECHANISM."
My said Invention has reference to certain improvements in connection with
screw propellers and their shafts and fittings for screw steamships or vessels, for thie
better propulsion of these ships, and in consequent improvements connected with
the rudder and stearing gear, all which will enable large ships to be built so as to
draw much less depth of water and to be either propelled at a higher speed or with
less power than heretofore, with equal or even greater stability and safer sailing.
qualities.
And in order that the nature, novelty, and mode of performing my said Invention
may be properly understood, I shall now proceed to describe the several Figures on.
the Sheet of Drawings which I have hereunto appended for the purpose of showing
the best modes and means I am at present aware of for putting the same into effect
or practice, the same reference letters indicating the same or similar parts in all the
Figures where shown.
Figures 1 and 2 are a sectional elevation and a corresponding horizontal section
respectively.of the stern part of a screw steamship, shown as fitted with one modi-
fication of my said Invention or improvements connected with the screw propeller,
and its shaft, gearing, and fittings, and with the stern of the ship and its rudders.
Referring to these Figures 1 and 2, the nature and novelty, of the Invention
consist in forming the large deep narrow part of the keel Z below the stern, soine-
times termed the "dead wood," where the screw shaft usually passes out through a
cylindrical tube or channel a little larger than itself, of two frames, as seen at A, A,
cach with an outer and inner skin or thickness of sheet plating A¹, A", in iron or
steel ships, or of planking in wood vessels, with angle-iron or other frames A111
between them, and a deep, narrow, longitudinal, radial, angled, or rectangular
channel B, B¹, between the frames A, A, formed with or having two vertical stern
posts A at the extreme stern (instead of one as formerly), joined below by a strong
sole or frame B, preferably hollow at b for the water to pass through, with
strengthening ribs b' across, with a deep parallel vertical recess B' on the inner
face of..and between the posts A², narrow transversely, that is, just wide enough to
allow the long, bush or lignum vitæ packed bearing block C of the stern neck
journal d of the screw shaft D to be raised to the usual level, as seen at 1 - - -
. 1, or
it might be higher out of the water, as indicated by the dotted line 1 - - - - 2, and
lowered quite down, as indicated at 1 - - 3, to near the keel, both in a new or
improved manner, as seen particularly in Figure 1, so that the screw E, which,
under these improvements, is secured and keyed on the extreme or overhanging stern
end of the shaft D, so that when the vessel is sailing in deep water it would. thus
work with its blades quite down below the bottom line --- of the keel Z of the
ship in solid water not disturbed by the pitching motion or displacement of the
ship.
--
The back end of this stern length D of the screw shaft would be connected or
coupled by a universal joint coupling D₁ to the back end of the shaft D, passing
out from the engines and engine-room, and when it is desired to get easily at and:
keep this universal joint coupling D' dry, it would be fitted in the compartment or
well B¹¹¹, close inside, or in front of the stern stuffing box tube F, F¹, passing out
through the end B" of the outer deep recess B, B', the stuffing box F of which.
would be made spherical, and formed and fitted in two parts on a deep.slide F"",
titted or mounted on the radially rising and falling ball tube F, F', of the screw.
shaft Don and over the strong planed water-tight jointed end plate F, jointed and
bolted or otherwise secured with an oblong slot in it over one in the end B of the

page_text: outer channel B; all with the stuffing boxes F and F and universal joint coupling
within a water-tight partition and dry well or chamber at B, over which a cover.
might be fitted on the quarter or under deck for the engineers getting in to inspect
and tighten up the suffing boxes F¹, F¹¹, and connect or disconnect this universal
joint coupling D¹.
The said carrying or raising and lowering stern journal bearing block C of the
screw shaft D may as usual be bushed with lignum vitæ or other hard wood, or be
made with a collar and grooved journal bearing of white or gun bush metal as a
thrust block to take a part of the end thrust off the universal joint coupling D¹; or
this could have its central steel ring or disc D³, with its radial journal arms D²,
formed or fitted with a hard polished spherical centre or ball D', between and work-
ing in the spheroidal end of the shafts D and D", which could thus receive the end
thrust in propelling the vessel forward, and so relieve the strain upon the driving
journal arms D2, as seen in Figure 1 A.
By one arrangement, as hero shown in the Drawing, the stern end of the screw shaft
D is raised and lowered through its carrying bearing block C, which has two lateral
journal arms c, working in hollow bearings c', in the two deep sliding and carrying
brass screw blocks C¹, working in planed recessed guides B¹, on the inside of the
stern posts A² of the stern frames A, A. These deep screw nuts or bushes C¹ work
on and are carried or raised and lowered, each by a strong vertical screw shaft or bar
C, working in a footstep bearing C, and upper or neck journal bearings at Cin
the stern part of the ship and on a deck frame, where the upper ends of the screw
spindles could be fitted with spur wheels C, turned by a central wheel C³ gear-
ing into the wheel C, and the central shaft of the wheel C can be driven by
hand and toothed wheels or screw gearing, or by small special single or double
cylinder engine C, for the purpose, or chain wheel and chain from the windlass and
hauling deck engines in common use; or other equivalent gearing may be used
instead of the screws C for the raising of the stern bearing block C and shaft D;
such as vertical rods fitted with screw or scroll racks, or links or chains worked by
ordinary geared wheels, screws, and scroll wheels, by hand or motive power.
The lateral swivelling stems c of the stern or neck journal bearing block C might
be nade long enough to work quite through and through the slide blocks c¹, C, if
the carrying or raising and lowering screws C¹ are fitted to work through these
blocks a little abaft or forward from these stems c, and likewise when this bearing
block O is carried and raised and lowered by any of these other arrangements of
lifting and lowering gear.
Although the universal joint coupling D1 of the screw propeller shaft D has been
herein described and shown in the Drawings as placed and fitted inside the ship and
stern stuffing box tube F, F, this being preferred for safety in case of breakage,
and convenience of examination and repair, yet still in many cases, as for the
smaller classes of ships or short voyage vessels, this coupling might be fitted in the
outer open chamber B, B¹, close up to the outer end of the stern stuffing -box tube
F, F, which in this case would be of the ordinary stationary construction hereto-
fore used, and not require the ball-and-socket stuffing box F", F; and sliding
frame F, F, described and shown.
Conjoined with this arrangement of these improvements connected with the pro-
peller, two rudders G would be used mounted to work close up to the stern frames
A, A, preferably in a flush line or plane with the outside shell or wall A'¹ of the
recessed or double stern post A, B, B¹, and having their back edge G¹ rather within;
and so as to work quite clear in front of and on each side of the stern posts A²; and
keel Z and propeller E.
The rudders would be jointed as usual, but to the vertical part A³ of the frame
A, and would have the upper posts or spindle ends G passed up through the bush
frames H on the deck, so as to be worked by any suitable gearing ranged and fitted in
a duplicate manner at the top of their rudder posts on a portable frame as H on the
deck, as shown in one arrangement detached in sectional elevation and plan in Figures
3 and 4; each rudder post G" having a screw toothed quadrant seginental wheel
g

page_text: itted on it, working into a screw on a horizontal spindle g¹, revolving in bush
ournal bearings h on the frame H, one on each side of the central hand wheel or
iller shaft I, also carried in bush bearings h¹ in the top of the frame H, and having.
loose wheel g² and g" on each end of the shaft inside the frame, gearing into
corresponding pinions g³, g¹¹¹, fast on the screw spindles g¹.
As seen in Figure 3 the central shaft I (which has the steering hand spoked
wheel I keyed on its front end) is bored hollow, and fitted with a central screw
spindle i, screwed powerfully out or in a short distance by the hand wheel i¹
working by a collar nut in its eye on the outer end of the spindle i, and in a thrust
socket screwed or otherwise secured on the outer end of the shaft J, all so as to
shift a duplex friction grooved clutch J, mounted on the centre of the hollow
shaft I, and secured by a cotter through a slot in this shaft to the inner end of
the screw spindle i, & so as to take into one or other of the corresponding angled
grooved and ring couplings formed on the inner face of each pinion g², g¹¹, according
as shifted and screwed up by the hand screw wheel ³, as desired, after both rudders
have been placed in a line with the keel, as for engaging and working the
port rudders G and simultaneously disengaging the starboard one, or vice versa,
engaging and working the starboard rudder at the same moment, and by the same
act disengaging the port rudder; the one rudder turns out from the port side and
the other from the starboard side, to port or starboard the ship respectively, by
the turning of the hand steering wheel I', the one rudder having first been turned in
towards the line of the koel before the other is turned outwards therefrom to so port
or starboard the ship.
The main stern frames A, A, behind each rudder G, G, is formed with a large
open, nearly rectangular, recess a through it, with strengthening ribs a¹ across, all
so that in steering the outer water is free to rush up through the openings b in the
keel B2 into the chamber B, B', and out through these openings a in the keel
frames A, A, or out through the back end between the stern posts A², over or under
the screw propeller, all as indicated by the arrows in Figure 1.
Instead of or in addition to the openings b (in the bottom B² below the keel, for
admitting water to the open channel B, B¹, of the screw shaft D) openings may be
formed in the side frames A and plating A¹, A", in front of the rudders at A* for
the water to flow in, by, and out through the said openings a behind the rudders
to relieve all counter-suction or pressure on their back surface, and so allow them
to be easily and freely actuated to effect the proper steadying of the ship.
The screw toothed segmental wheels may be mounted loosely with deep eyos
on the top of each rudder post G", and coupled or uncoupled when it is to be
brought into action to bring up the rudder to starboard or port the vessel, or put
it out of action to let the rudder fly back to the line of keel by the forward motion
of the ship and action of the water, all respectively by an angled groove or ring,
disc, clutch, or coupling, such as seen at 7, 22, in detached sectional elevation in
Figures 5 and 6, when desired, and that these segmental wheels g, g, may be made
large enough in diameter to work into the same or reverse cut screws on the central
shaft I, which in this case need not be made hollow.
It is to be understood, however, that other arrangements of rudder gearing may
be used, such as oscillating or sliding vanes working out through narrow angled
chambers under the port and starboard quarters, the one being projected out into
action as the other is drawn in out of action by suitable lever or rack and wheel gear.
When twin screw ships are fitted on this new or improved system the ordinary
arrangement of central rudder would do, and two double-cased vertical radial
channels or chambers would be fitted one under each quarter, for the shafts of the
port and starboard screw shafts to be raised and lowered, with the screw propellers
quite forward in advance of the centre stern post, so that the rudders could be put
hard a-port or a-starboard without interfering with the action of either screw į
either or both screw propellers, separately or simultaneously, could be raised and
lowered by the screws or equivalent gearing, as herein-before described, to propel
the ship in shallow water or in deep water to give the improved action and

page_text: propelling effect described in reference to the single screw arrangement, shown in
Figures 1 and 2 of the Drawings.
The following are some of the advantages which will result from, or be gained
from, the adoption of my said Invention.
Steamers built with the improvements herein specified will admit of much more
beam and much less draught of water than those constructed on the ordinary
stationary propeller and single rudder plan; thus shallow waters, estuaries, and
rivers which are not navigable to the larger steamers of which the merchant
marine service now mainly consists, and bars, similar to that at New Orleans and
other harbours, impracticable to these steamers from their great draught of water
necessary to give sufficient diameter to their propellers and secure their proper
immersion, will be easily navigable and perfectly practicable to steamers of greater
carrying capacity, constructed in accordance with the improvements herein specified.
Steamers built with my said improvements will possess greater strength, and will
be safer and better sea-boats than the steamers now in use by reason of the superior
proportions of construction of which these improvements admit; their carrying
capacity will be increased without a proportionate increase in the cost of construc-
tion; and the diameter of the screw propeller could be considerably increased as
might be required in vessels of equal tonage; there will be no vibration and no
"racing" of the engines at sea, and therefore secure the greatest possible immunity
from many accidents arising from convulsions resulting from these causes and
common to ocean steamers now in use; security against "listing" and consequently
against the "heeling error" of compasses; while the economy of motive power by
providing against "slip" will be very considerable.
Further, the density of water increasing in the ratio of depth, the motive power
for steamers of, say, 360 feet in length and 55 fect of beam, drawing, when loaded,
about 20 feet of water, and constructed with the improvements herein specified,
would be more directly and economically applied than on steamers of the proportions
of which the first class vessels of the merchant marine service now consist, encoun-
tering as they do, from their great draugh of water, an important resistant in the
increased density of the water; besides losing even in moderate weather sometimes
as much as 30 per cent. of their motive power in "slip" by pitching.
In case of any accident occurring to the machinery at sea rendering steam as a
motive power impracticable, the propeller could be raised out of the water; and
steamers having the improvements herein specified could therefore proceed much
more advantageously under sail than steamers without said improvements.
Further, all necessary repairs connected with the propeller could be made either
at sea or in port without docking; those damages which not unfrequently result
from hawsers fouling the propeller shaft in port or elsewhere will be entirely
avoided; while, by virtue of the improvements herein described, steamers would be
'constructed so as to admit of being shifted without ballast; and even of crossing
the Atlantic in safety with no cargo excepting an ordinary supply of coal..
Protection from certain sea damages to which other steainers are exposed being
'secured to steamers possessing the improvements referred to (such as losing
propellers, carrying away rudders, rudder posts, and steering gear), insurance risks
would be reduced, and insurance companies would accept risks on such steamers and
on their cargoes on the most favourable conditions; and other advantages would
accrue from reduced dues in harbours and ports.
In addition to these and other advantages accrueing to the merchant marine
steamship service from the adoption of the improvements herein specified, steamers
constructed with said improvements will be vastly superior as passenger vessels,
inasmuch as the vibration, rolling, listing, and other discomforts which aro now
experienced in transatlantic and other long voyages will be reduced to a minimum,
and the greatest possible comfort secured.
Having now described the nature of my said Invention and the manner of
performing the same, I have to state that I do not confine myself to the precise-
details herein described or delineated, but what I consider novel and original and

page_text: therefore claim as the Invention secured to me by the herein-before in part recited
Letters Patent is,―
First. The general arrangement for and method of raising and lowering screw
propellers and their shafts, and the fittings connected therewith and therefor, of
steamships or vessels with double rudders and their fittings, all substantially as and
for the purposes and advantages herein described in reference to and shown in the
accompanying Drawings, or any mere modification thereof.
Second. The construction and arrangement of a raising and lowering screw
propeller E overhung on its shaft D quite behind or abaft the stern posts A³, A²,
with two rudders G quite forward or in advance of the stern posts, with inlet and
outlet water spaces b, a, to and from the chamber B, B', for the screw shaft D
between the rudders, all substantially as and for the purposes and advantages herein
described in reference to and shown in the accompanying Drawings, or any mere
modification thereof.
Third. The raising and lowering of the screw propeller shaft D of steamships or
vessels by an arrangement of duplex screws C and screw blocks or their equivalent,
with open free water circulating chamber B, B¹, a, b, for the shaft D to move in, all
substantially as herein described in reference to and shown in the accompanying
Drawings.
Fourth. The fitting of raising and lowering screw propellers of steamships or
vessels with two rudders G, G, one on each side of an open free water circulating
chamber B, B1, a, b, all substantially as herein described in reference to and shown
in the accompanying Drawings, or any mere modification thereof.
In witness whereof, I, the said John William Sadler, have hereunto set my
hand and seal, this Nineteenth day of December, in the year of our Lord
One thousand eight hundred and seventy-seven.
Witness,
W. R. M. THOMSON,
Patent Agent,
Glasgow.
JOHN W. SADLER. (L.S.)