IMPROVE- MENTS IN ARRANGEMENTS FOR APPLYING AUXILIARY POWER TO SAILING SHIPS
Year: 1866

page_text: LETTERS PATENT to Robert Duncan, of Port Glasgow, in the County of..
Renfrew, North Britain, Shipbuilder, for the Invention of "IMPROVE-
MENTS IN ARRANGEMENTS FOR APPLYING AUXILIARY POWER TO SAILING
SHIPS."
Sealed the 4th June 1867, and dated the 6th December 1866.
PROVISIONAL SPECIFICATION left by the said Robert Duncan at the
Office of the Commissioners of Patents, with his Petition, on the 6th
December 1866.
I, ROBERT DUNCAN, of Port Glasgow, in the County of Renfrew, North
Britain, Shipbuilder, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN ARRANGEMENTS FOR APPLYING AUXILIARY POWER TO SAILING
SHIPS," to be as follows, that is to say:-
This Invention relates to arrangements for applying auxiliary power to
sailing ships, and has principally for its object to enable them to cross the
belts of calm, such as are met with in most East India and China voyages;
and the Invention consists in fitting or providing one or more boats, such as are
ordinarily carried by ships of a size likely to adopt the present Invention, with
propelling apparatus arranged to be worked by steam generated in one or
more boilers on board the ship. When the auxiliary power is to be used the
boat or boats will be lowered into the water either by hand or by machinery
in the boat, and be connected to the ship by booms and guy ropes, or other
suitable tackle, and the engines or machinery in the boat or boats will bo

page_text: supplied by means of flexible piping with steam from the boiler or boilers on
board the ship. With such arrangements boats of moderate size may be
fitted with much more powerful propelling apparatus than when each carries
in addition a boiler for supplying the requisite steam.
The details are obviously susceptible of many modifications. Various known
kinds of propelling apparatus may be employed, but it is preferred to use screw
propellers driven each by any simple form of engine. It is also intended to
arrange for the easy removal of the propellers and engines from the boats
should these boats be required for other uses. The having on board a boiler
or boilers for the purposes herein-before described will render it unnecessary
to have on board special boilers for working winches or capstans, or for
obtaining fresh water. The auxiliary propelling boats may be advantageously
used otherwise than in calms out at sea. Thus they may be used in
manoeuvring the ship in harbour, and in taking her up or down a river in the
absence of local tug steamers, and they might be the means of saving the
ship by assisting her away from a position of danger.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Robert Duncan in the Great Seal Patent Office on the 5th
June 1867.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ROBERT
DUNCAN, of Port Glasgow, in the County of Renfrew, North Britain, Ship-
builder, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Sixth day of December, in the year of our Lord One
thousand eight hundred and sixty-six, in the thirtieth year of Her reign, did,.
for Herself, Her heirs and successors, give and grant unto me, the said
Robert Duncan, Her special licence that I, the said Robert Duncan, my
executors, administrators, and assigns, or such others as I, the said Robert
Duncan, 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 Isle of Man, an Invention for "IMPROVEMENTS IN ARRANGEMENTS
FOR APPLYING AUXILIARY POWER TO SAILING SHIPS," upon the condition (amongst
others) that I, the said Robert Duncan, my executors or administrators, by an
instrument in writing under my, or their, or one of their hands and seals,

page_text: 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 Scal Patent Office within six calendar months next and
immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Robert Duncan, do hereby declare the
nature of my said Invention, and in what manner the same is to be performed,.
to be particularly described and ascertained in and by the following statement
in writing, reference being had to the accompanying Drawings, that is to'
say:-
My said Invention relates to arrangements for applying auxiliary power to
sailing ships, and has principally for its object to enable them to cross belts of
calm, such as are met with in most East India and China voyages.
The desireability has long been recognised of adopting some satisfactory.
means of obviating the waste of time incurred from calms by sailing ships
engaged upon long voyages; but in applying auxiliary steam power for that
purpose too much has hitherto been attempted. Too much power has been
carried merely to steam through the belts of calm, whilst it has been too little
for steaming effectually against strong contrary winds and monsoons. The
ship has been cut up and filled with machinery, boilers, and fuel, which for the
greater part of the voyage were useless dead weight, and the expence and
inconvenience of which were but poorly compensated for by steaming across
calms, whilst against contrary winds the insufficiency of the power could only
result in a wasteful expenditure of fuel, carrying capacity, and freight.
In practically carrying out my present Invention I avoid both the objections'
herein-before indicated. I consider that calms constitute the only waste or
loss. in, the Eastern or other long voyages of sailing ships that can be satis-
factorily dealt with. In the contrary monsoons time is also lost, but that
occurs even with full-powered steamers and to a comparatively not much less
extent than with smart sailing ships beating through; besides, sailing ships are
likely to continue to compete very advantageously with full-powered steamers
oi long voyages in consequence of the meteorology of the sea becoming so
well, understood, and of the certainty with which the steady trade winds and
monsoons.can be relied upon for the greater part of the voyage. There is
thus consequently the less reason for attempting to deal with any loss a sailing
ship may incur from contrary winds, whilst the application of auxiliary power
in the calms alone can be effected by means of my improved arrangements at
a cost bearing no comparison with the advantages gained by shortening the
duration of the voyage, and thereby reducing the current expenditure of the ship.
In order that my said Invention, and the manner of performing the same,

page_text: may be properly understood I have hereunto appended a Sheet of explanatory
Drawings to be herein-after referred to, and representing by way of example
what I'at present believe to be the most convenient and satisfactory mode of
applying my improved arrangements in the case of a sailing ship of about
1,000 tons, but to the precise details of which it must be understood I by no
means restrict myself.
The ship is represented in stern elevation in Figure 1, and in side elevation
in Figure 2; Figure 3 is a longitudinal vertical section of a boat employed in
applying the auxiliary power; and Figure 4 is a transverse vertical section
thereof; whilst Figure 5 is a plan of the boat's engines.
My said Invention consists in fitting or providing one or more boats, such
as are ordinarily carried by ships of a size likely to adopt the Invention, with
propelling apparatus arranged to be worked by steam generated in one or
more boilers on board the ship.
In the example shown in the Drawings a single boat B is used, being
represented as in action at the side of the ship in Figures 1 and 2; this boat B
simply forms part of the ship's equipment, being substituted for one of the
ordinary boats, and thus not constituting any addition. Its place when on
board is indicated by dotted lines at A. The engines only are in the boat, the
boiler C and the fuel being on board the ship, and the weight of the boat is
easily manageable with ordinary davits and tackle, whilst with equal weight and
handiness not one-tenth of the power could be obtained and applied by means
of a boat of the same size carrying boiler and fuel in addition to the engines.
The boiler C may be of any approved construction, but I prefer such a one as
will give the largest amount of power with the smallest size and space. In
the example delineated the boiler C is a horizontal cylindrical tubular one,
about four feet six inches in diameter, and with a sufficient length of tube and
fire-grate to raise steam of from fifty to sixty pounds pressure per square inch
so as to exert and maintain a power of about one hundred horses' effective. I
propose to use fresh or distilled water in the boiler when towing with the
boat, the supply being then taken from water tanks in the hold. When the
towing boat is not in use the boiler may be used for actuating steam winches
for working the sails, for raising the anchors, or for loading or discharging the
cargo; and when steam is not required for these purposes, or even while being
used with them, the boiler may be used with a condenser for distilling water
to supply the water tanks with fresh water for its own subsequent use and for
the use of the crew and passengers. When the boiler is in use for the
ordinary purposes indicated it will give sufficient steam with the natural
draught of the funnel with slow combustion and small consumption of fuel,

page_text: but when it is in use with the towing boat the draught may with advantage
be forced by means of a steam jet in the funnel. For the purpose of keeping
the funnel snug when the ship is under sail, and in order to provide sufficient
length for the draught, the funnel may be made either telescopic or with a
hinge joint. I believe the best position for the boiler on the ship's deck to
be between the main batch and the foremast, as represented in the Drawing,
with a steam winch D just before the main batch and the firing end of the
boiler towards the winch with the stoking space between, so that one man'
may attend to both. The fore end of the boiler should be to the after end of
the cooking galley E with an iron bulkhead between having a door in it to
give easy access to the boiler, smoke box, for cleaning the tubes, and for
repairs. The galley and deck-house in large ships being usually from ten to
twelve feet wide, the space occupied by the boiler with clearance for heat and
with a working passage on each side will not exceed six feet, so that with an
iron bulkhead on each side of the boiler a wing space or bunker on each side
will be available for stores or coals. If used wholly for coals these side
bunkers will hold about twelve tons, sufficient for three days' hard steaming
with the towing boat at full power. When utilising all the power in one boat,
as in the present example, such boat should be of about the size of an ordinary
ship's launch, that is to say, about twenty-five feet long, eight feet beam, four
feet depth amidships, and five feet depth at the stern. The boat is made, as
shown, with a deep heel to give about three feet draft of water aft, and in
order to admit of the application and complete immersion of a propeller screw.
of about five feet in diameter. The propeller shaft is carried through the
stern post as closely as possible to the bottom of the beel, and the lower half
of the screw is below the boat. I prefer to use a four-bladed fishtail screw
for greater propelling power and freedom from vibration. The propeller shaft
is di-posed at an angle, so that the engines can be conveniently arranged in
the middle of the boat.
The engines represented in the Drawing consist of two direct-acting
oscillating cylinders, without condenser, and with the valve gear and other
details constructed in the simplest possible manner, being designed to develop
about one hundred horses' power. The engines, framing, and sole plate are
so arranged and combined as to admit of being easily removed entire when
the boat is required for other purposes. The shafting is represented as
arranged for hoisting the boat out of the water by its own power, being
prolonged forward to the stem, the stem bearing forming a thrust block, or
additional thrust block for the shaft. Close to the stuffing box at the inner
end of the stern pipe the shafting is fitted with a disconnecting coupling f, by

page_text: means of which the screw can be thrown out of gear when using the engines
for hoisting. Just in front of the coupling f the shaft has on it a small
barrel g, round which is to be turned the heaving end of the after tackle
being led off from it by hand; the after tackle fall block is hooked to a sling
fast or hooked to a ring bolt fixed to the inner stern post, the sling having
guys connected to ring bolts at the sides under the gunwale. The hauling
part of the tackle goes direct from the davit block to a leading block under
the barrel g, and thence to the barrel. A similar barrel i is fitted on the
forward part of the shaft close to the stem thrust bearing, and an eye bolt or
swivel ring is fitted to the upper part of this bearing for the forward tackle
fall block to be hooked to; the heaying end of this tackle may be passed
directly upon the barrel i, or it may be first passed through a leading block at
the keel. Immediately abaft the main thrust bearings at the engines the
shafting is fitted with a second disconnecting coupling k to allow of the
engines being thrown out of gear when it may be desired to work the screw
propeller by hand. For working the shaft by hand there is fast on it a spur
wheel 7, with which there can be put into gear, when required, a spur wheel
or pinion m, which is carried above on a short shaft formed with a handle
which can be actuated by two or more men. The driving wheel or pinion m
can be made of any size found suitable for effectually actuating the propeller
shaft. The steam is conveyed by a copper or other metal pipe p from the
boiler C to the ship's bulwarks, and it has there connected to it with a swivel
joint a horizontal length of metal pipe g, the outer end of which is supported
by guys and stays; from the outer end of the metal pipe q'a length of flexible
tubing of vulcanised rubber prepared for the purpose, or of other suitable
material, extends down to the engines in the boat, being connected to a stop
valve r, from which branches s go to the valve casings of the cylinders. The
exhaust steam passes by branches to a vertical or slightly inclined pipe u,
which I prefer to have made of sheet iron or drawn tubing, and to fit with
shrouds and tackle to serve as a mast to carry sail, should the boat cver
require sail in an emergency. When the boat is towing I prefer to have the
towing rope hooked or fixed to the ring bolt at the stem, and to pass thence
to and through a ring or hook fixed at about the centre of the boat to a beam
or to the deck when there is one over the engines, as shown in the Drawing.
From the centre attachment the towing rope passes aft to the end of a boom v
guyed out from the ship's side, and thence further aft to a sheave or hawser
hole w in the bulwarks to a bit inside. A man in the stern of the boat can
easily exert whatever steering action may be required by passing the tow rope
to either quarter of the boat. The boat is also connected to the ship forward

page_text: by means of a boom and guy ropes, the position between the two booms
securing the necessary steadiness in towing, and permitting the boat to rise
and fall with the undulations of the sea clear of the ship's side without risk
of injury.
In addition to the advantages already herein-before indicated as belonging
to my system of and improved arrangements for applying auxiliary power to
sailing ships they possess the following, the stating of which will conduce to
the said improved arrangements being the more fully understood and the more
satisfactorily carried out in practice, that is to say:-
My improved auxiliary steam power may obviously be applied to any ship
without altering the hull, the placing and securing of the boiler, on deck, and
the fitting of the deck-house to suit, being the principal items affecting the
ship, and being all such as can be done without delay whilst the ship is afloat
or loading. The boilers and boats being made independently of any ship, and
being suitable for any ship, may be kept in stock on shore, or they may be
transferred from one ship to another at a very small outlay; the same amount
of power could not be applied directly to the ship within herself without great
and expensive alterations in the hull. Taking as a standard the example
herein-before described and shown on the accompanying Drawings, namely, a
ship of 1,000 tons with a propelling power of 100 horses, the ship will be towed
at the rate of about four knots an hour in a calm, equal to about 100 miles
per day, with a consumption of fuel of about 4 tons per day. The average
breadth of the calin belts of an Eastern voyage is about 300 miles, the
ordinary rate of progress through them with light baffling airs being about
a knot an hour, which is equivalent to thirteen days; a speed of four knots an
hour will take the ship through in three days, and save ten with an expenditure
of only twelve tons of coal. It is also well known that in certain seasons the
calms of the Indian Ocean and the Eastern Archipelago cover more than
1,000 miles of latitude, and ships lose weeks and sometimes months in
creeping through them. With my auxiliary power, however, the 1,000 miles
could be run through in ten days with a consumption of forty tons of coal;
and the time which has hitherto been looked upon as certainly lost may as
certainly be saved at a very moderate expenditure. The machinery takes
nothing from the carrying capacity of the ship, and the coal not much; as a
matter of dead weight the whole machinery and coal for ten days' steaming
do not add more than three inches to the draught of water of a ship of 1,000
tons, and many ships carry ten times the weight as ballast with considerably
less advantage. Although I do not contemplate the use of my auxiliary
power against contrary winds it may still be advantageously used otherwise

page_text: than in calms; thus it may be used in manoeuvring the ship in harbour, and
in towing her up or down a river in the absence of local tug steamers, and it
might be the means of rendering great assistance to the ship in positions of
danger.
Having thus particularly described my said Invention, and the manner
in which the same is to be performed, I have to state that I do not restrict
myself to the precise details herein described or delineated; but that what I
believe to be novel and original, and claim as the Invention secured to me
by the herein-before in part recited Letters Patent is, the providing of sailing
ships with auxiliary steam propelling apparatus arranged in a boat or boats to
act alongside, such apparatus being supplied with steam from a boiler or
boilers on board the ship, substantially as herein-before described.
In witness whereof, I, the said Robert Duncan, have hereunto set my
hand and seal, this Fourth day of June, in the year of our Lord One
thousand eight hundred and sixty-seven.
Witness,
EDMUND HUNT,
Patent Agent,
Glasgow.
ROBT. DUNCAN. (L.S.)